Original Link: https://www.anandtech.com/show/10116/the-dell-xps-15-9550-review
The Dell XPS 15 9550 Review: Infinity Edge Lineup Expands
by Brett Howse on March 4, 2016 8:00 AM ESTIt was roughly a year ago that we had a chance to review Dell’s XPS 13, which was the first laptop from Dell to feature the Infinity Edge display. In addition to making the laptop look as much like a bezel-less display as possible, it also let Dell squeeze a 13-inch laptop into a much smaller chassis. The XPS 13 is still, to this day, unparalleled in the PC space in this context. So the obvious question at the time was when or if Dell was going to do the same to the rest of the XPS lineup? That question was answered in October 2015, when Dell launched the updated XPS 15 with Skylake and Infinity Edge. Just like the XPS 13 before it, the laptop was bezel-less and the larger 15.6-inch model fits into a laptop chassis that would normally house a 14-inch display. Smaller, lighter, and with the same styling as the XPS 13, Dell has the potential to set the bar higher in the larger laptop segment as well.
With the updated chassis also came an update in the internals. Dell moved to Skylake for the 9550 model, with Core i3, i5, and i7 models based on Intel’s H Series chips. The Core i3-6100H is a dual-core 35-Watt CPU, and the Core i5 and i7 are both quad-core 45-Watt processors. The base RAM option is 8 GB of DDR4, and you can order up to 16 GB from Dell, although this laptop does have SODIMM slots so you can add up to 32 GB if needed. Graphics on the Core i3 model is just the base integrated solution, but all other models come with a 2 GB GeForce GTX 960M graphics card, which has 640 CUDA cores, 1096 MHz frequency plus boost, and a 128-bit GDDR5 memory subsystem.
Dell offers two display choices. The standard model is a 1920x1080 15.6-inch model, or you can opt for the $350 upgrade to a 3840x2106 touch display which has a backlight which can cover the Adobe RGB color space.
Dell XPS 15 9550 Configurations | |||
Core i3 | Core i5 | Core i7 (Model Tested) |
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GPU | Intel HD 530 | Intel HD 530 + NVIDIA GeForce GTX 960M w/2GB GDDR5 |
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CPU | Intel Core i3-6100H (35w) Dual-Core w/HyperThreading 2.7 GHz |
Intel Core i5-6300HQ (45w) Quad-Core 2.3-3.2 GHz |
Intel Core i7-6700HQ (45w) Quad-Core w/HyperThreading 2.6-3.5 GHz |
Memory | 8-16GB DDR4-2133 RAM Two SODIMM slots, 32GB Max |
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Display | 15.6" IPS 1920x1080 sRGB | 15.6" IPS 1920x1080 sRGB Optional 3840x2160 IGZO IPS w/Adobe RGB color space and touch |
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Storage | 500GB 7200 RPM Hybrid w/32GB NAND | 1TB 5400 RPM Hybrid w/32GB NAND | 256/512/1024 GB PCIe NVMe SSD (PM951) |
I/O | USB 3.0 x 2 w/Powershare SD Card reader 1 x USB 3.1 Gen 2 Type-C w/Thunderbolt 3 Headset Jack HDMI |
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Dimensions | (mm) : 357 x 235 x 11-17 (inches) : 14.06 x 9.27 x 0.45-0.66 |
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Weight | With 56 Wh Battery 1.78 kg / 3.9 lbs With 84 Wh Battery 2 kg / 4.4 lbs |
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Battery | 56 Wh | 56/84 Wh | |
Price | $999+ | $1199+ | $1499+ |
Dell offers a 500 GB hybrid hard drive as the base offering, and a 1 TB hybrid upgrade, or you can get rid of the spinning disk altogether and choose PCIe based solid state drives, with 256 and 512 GB options. If you elect for an SSD, you also have the option of getting an 84 Wh battery instead of the standard 56 Wh version. The 84 Wh battery takes up the space where the 2.5-inch hard drive would have been, which is a smart idea.
Wireless options are interesting as well. The base model comes with a 2x2 802.11ac wireless card, but the upgraded models feature a 3x3 802.11ac offering, which is rare indeed on a Windows PC. This gives a maximum connection rate of 1.3 Gbps, assuming you have a router that can support 3x3 connections. This should, in theory, give a lot better throughput than the more common 2x2 implementations we see on most notebooks, but this is certainly something we’ll test later on.
We also see Dell continue to support Thunderbolt 3 ports, which is coupled with a USB Type-C connector. This port provides 40 Gbps of bandwidth when in Thunderbolt mode and can be used for various peripherals including Dell’s own Thunderbolt dock which gives a single cable docking solution. The dock adds Gigabit Ethernet, HDMI, two DisplayPort connections, VGA, three USB 3.0 connectors, two USB 2.0 connectors, headset, and even a speaker output. The laptop itself also has two more USB 3.0 ports, HDMI, and a SD card reader.
Overall this is a pretty compelling package. Dell is offering a 15.6-inch notebook which is about the same size as a 14-inch model, but at the same time they’ve found enough space to pack in plenty of performance, along with Thunderbolt 3 and one of the few 3x3 wireless implementation to date.
Design
There’s certainly some issues when competitors outright copy another’s design, but luckily for Dell they have one of the most appealing laptops already in the XPS 13. The XPS 15, other than the larger size, is extremely similar to its source of inspiration, and that’s a good thing. Moving to the Infinity Edge display brings the same strengths and weaknesses along with it, but the one thing you’d have a hard time knocking is the look of this laptop.
Dell uses CNC aluminum on the top and bottom of the laptop, which gives it that great cool feeling of metal when you are holding it in your hand. But open up the XPS 15, and you get to look at a soft touch carbon fibre weave which surrounds the keyboard deck. This soft touch material makes for a positive typing experience, and by going to black on the keyboard, Dell gets to avoid the contrast issues that happen on other machines with lighter colored keys. Although the laptop looks like a bit of a sandwich when its closed, I think the color scheme works very well and gives the XPS lineup a premium look.
The bottom of the laptop is as well thought out as the XPS 13. There’s a large vent for cooling, and the rubber feet are almost the entire width of the machine. There’s no issue with sliding around on a table top when you are using the XPS 15 thanks to these feet, and that’s not always something I can say about other laptops. It also gives you a nice stable platform in your lap. Another great XPS touch is that all of the FCC information, serial numbers, and other markings, are collectively put under an XPS badge on the bottom of the device to keep the look as clean as possible.
The left side of the laptop has the power connector, USB 3.0 Type-A port, HDMI, a USB 3.1 Gen 2 Type-C port which supports Thunderbolt 3 and power as well, and a headset jack. The right side has another USB 3.0 port, SD card slot, and a push button battery gauge. With the inclusion of USB 3.1 Gen 2 and Thunderbolt support there is a pretty big amount of bandwidth for any accessory, but as that market matures the USB Type-A connectors are likely going to see more use. It would have been nice to see a third USB port on the side but that’s a minor issue. Dell does sell a USB-C adapter which gives HDMI, VGA, Ethernet, and USB 3.0 all in one nice compact package which works well.
Once opened, the Infinity Edge display captures your eye, and the minimal bezel looks as good, or even better, than the smaller XPS 13. The webcam is still in a poor location though, tucked under the display and pointing up, which doesn’t flatter anyone. Considering the large bezel at the bottom of the display, I’d be fine with the screen shifting down slightly so the webcam could be fit above the screen, but I’m not a big user of a webcam so it’s not a big issue for me. If you do utilize a webcam a lot, this is not ideal and an external one might be better. I’d also like to see Windows Hello support in a premium machine such as this. Microsoft was able to fit it into the Surface Pro 4 and Surface Book with minimal bezels, so it can be done.
Taking a look at the keyboard, it’s very possible this is the exact same keyboard as on the XPS 13. It has the same white backlighting with high, low, and off settings, and the same layout as well. Dell didn’t try to squeeze a number pad into this 15.6-inch machine, and that’s a good thing since it would be very compromised with the smaller chassis this fits into. Key travel is 1.3 mm, which is adequate, and on the XPS 13 it was likely all that could be done thanks to the very thin body, but on the thicker XPS 15 I would have liked some more depth. The actuation force is also pretty light. The keyboard is ok but it’s not the best I’ve used, especially on a larger device.
Dell has gone with a Synaptics trackpad, and it is both very large and very smooth. Dell uses the Microsoft Precision Touchpad standard for their software, and although it lacks the outright customization of some of the other packages, in my time with the XPS 15 I found the touchpad to be excellent. The large size is very welcome, and it’s very precise while at the same time being very smooth. Two-finger scrolling works very well. There are not many options for three and four finger gestures with the Precision Touchpad, with three-finger tap opening Cortana, and four-finger tap opening Action Center. There are no other choices other than to swap those or disable it.
The overall design of the XPS 15 is as ground-breaking as the XPS 13 before it. By shrinking the bezels, Dell is able to fit a 15.6-inch device into a much smaller chassis, which makes it much more portable. The laptop itself is only 17 mm (0.66”) thick at its widest point (not including the feet) and weight with the 56 Wh battery is 1.78 kg (3.9 lbs) which is very light for a 15.6-inch machine. If you step up to the 84 Wh battery, that bumps the weight to 2 kg (4.4 lbs) which is still pretty respectable.
System Performance
The XPS 15 is offered with three processor choices. The base model is the 35-Watt Intel Core i3-6100H, which is a dual-core Skylake chip with a 2.7 GHz frequency and 3 MB of cache. While I’m sure that it’s fine for most tasks, the base model is also lacking a discrete GPU and means you are only going to be using the integrated graphics, which in this case is the HD 530. I would expect the bulk of Dell’s sales to be the Core i5 and i7 models, which also come with the NVIDIA GeForce GTX 960M graphics card. The Core i5-6300HQ is a quad-core, 45-Watt part, that runs between 2.3 and 3.2 GHz, and it has a 6 MB cache. The top option is the Core i7-6700HQ, which includes HyperThreading (the Core i5 lacks this but the Core i3 has it) and a base frequency of 2.6 GHz with a turbo frequency of 3.5 GHz. The Core i7 is the model that was provided to us for this review.
On the memory side, this device includes two SODIMM slots which is a nice bonus for upgradability. The base offering is 8 GB of DDR4-2133, and you can buy it with 16 GB as well, or if you want to add your own DIMMs you can put 32 GB in this machine. For storage, hybrid hard drives are at the low end of the device range, but Dell ramps up to PCIe based SSDs on the higher priced models. The review unit has a PM951 Samsung drive, which is the TLC version that we’ve already seen in many notebooks this year. Read speeds are generally great, but write speeds will be among the slower PCIe SSDs thanks to the TLC.
I’ve run the XPS 15 through our standard notebook suite, along with a couple of other tests as well. All laptops in the charts below are from our Notebook Bench, and if you’d like to compare the XPS 15 to any other device we’ve tested, please check it out here. The previous generation XPS 15 9530 in the charts has the Core i7-4702HQ processor, GTX 750M GPU, 3200x1800 display, and a 91 Wh battery. The Lenovo Y700 is a device that we just reviewed and has the same CPU and GPU as the XPS 15 9550, and I thought it would be interesting to also see the XPS 13 here as well, although this is the Broadwell version we reviewed last year. This is a Core i5-5200U CPU, 3200x1800 display, and 8 GB of memory.
PCMark
PCMark attempts to recreate actual workloads that people would use every day, and with version 8 they have several tests to focus on workloads for those tasks. Home includes web browsing, gaming, photo editing, and video chat. Creative has web browsing, photo editing, group video chat, transcoding, and some gaming, and Work has document editing, spreadsheets, and video chat. Pretty much all aspects of the device are tested, and even things like the display resolution can impact the score. The UHD resolution on the review unit impacts these scores quite a bit in fact, with the XPS 15 often quite low compared to the Lenovo Y700 which has the same CPU and GPU but a 1920x1080 display.
Cinebench
Cinebench is a CPU heavy workload which renders an image. It can use all cores and likes more MHz as well. Just like the Lenovo Y700, I found the XPS 15 wasn’t a big jump in performance with Skylake compared to Broadwell and even some of the later Haswell Core i7 parts. It is however a sizeable jump over the outgoing XPS 15 9530.
x264
This test does video transcoding, and much like Cinebench is strongly influenced by CPU performance. More cores and higher frequencies are the name of the game here. Just like Cinebench, there also isn’t an increase in performance with Skylake on these tests compared to Broadwell or later generation Haswell chips like the i7-4720HQ, which can turbo up to 3.6 GHz compared to 3.5 GHz on the i7-6700HQ. But it is still a big jump over the i7-4702HQ found in the XPS 15 9530.
Web Tests
I’ve mentioned this a few times already but its worth repeating. Since the launch of Windows 10, we’ve switched from using Google Chrome for web testing to Microsoft Edge. Edge has performance that is quite a bit closer to Chrome now, surpassing it in some tests and behind in others, but both are capable browsers. As such, I’ve labeled the older laptops to let you know which browser was used at the time they were tested.
With a quad-core Skylake processor, which now supports Intel’s Speed Shift technology, the XPS 15 scores very well in our web results. The bursty nature of the web tests really plays into the hands of Speed Shift and lets the processor quickly get up to maximum frequency to perform the task, and make for a more responsive browsing experience.
GPU Performance
Other than the base model Core i3 powered XPS 15, all of the other models feature a 2 GB NVIDIA GTX 960M graphics card. The outgoing XPS 15 that we last reviewed featured a GT 750M, so the move to a Maxwell card should offer a better overall experience and with a more efficient design, which may come into play with the smaller chassis on the new XPS 15 9550.
The laptop was run through our standard gaming workloads. Of note is the Lenovo Y700 which has the same CPU but a 4 GB version of the GTX 960M, compared to the 2 GB one offered by Dell. We’ll see if that comes into play in the games we have here. The higher memory capacity should help as the resolution increases, but the GTX 960M is not going to be sufficient to game at UHD resolutions unless the game is not very demanding.
As always, you can compare the XPS 15 to any other laptop we’ve tested using our Notebook Bench.
3DMark
Our first synthetic test is FutureMark’s 3DMark. The latest 3DMark has several subtests, which start with the most demanding, Fire Strike, and decrease in demand going to Sky Diver, Cloud Gate, and Ice Storm Unlimited. The GTX 960M in the XPS 15 is fairly close to the Y700, which isn’t a shock, and the performance is a good step up from the GT 750M in the older XPS 15.
GFXBench
On our second synthetic test, we see the XPS 15 slotting right in around the same performance level as the Y700. Pretty much any PC with a discrete GPU can handle this benchmark at well over 60 FPS.
Dota 2
This Multiplayer Online Battle Arena game was recently revamped with a new game engine, which offers better visuals, but one that can still be played on low end hardware. The XPS 15 can handle this game very well at our enthusiast settings.
Tomb Raider
The latest version of this franchise has recently been released, but the original version can still be punishing on laptop graphics, especially with TressFX enabled. The XPS 15 can handle this game fairly well until you enable TressFX at 1920x1080, and then it struggles. It’s still a big jump over the older GT 750M equipped XPS 15.
Bioshock Infinite
The XPS 15 can handle this game fairly well, but at the highest settings we test it will struggle. The performance is once again a big jump over the outgoing GT 750M, and the GTX 960M gives us over double the performance of the Surface Book’s GT 940M as well.
Dragon Age Inquisition
Bioware crafted a great game with Dragon Age Inquisition, and with maximum settings it can be punishing to lower end GPUs. The draw distances are quite impressive. The XPS 15 struggles at 1920x1080 Ultra, and some tweaking using the GeForce Experience would be needed to get an acceptable frame rate on this game. You can see that the XPS 15 pretty much mirrors the Y700 here, despite the Lenovo GPU having double the RAM on the GPU.
Shadow of Mordor
The well received action-adventure game from Warner Brothers and Monolith Productions uses the LithTech game engine, and with everything set to maximum at 1080p, the GTX 960M barely keeps an average over 30 frames per second, so once again this test is a bit too demanding for this laptop, but again the limited VRAM on the GPU does not seem to be affecting it at the resolutions and frame rates that the lower powered GTX 960M can achieve.
GRID Autosport
The EGO 3.0 engine can be tweaked quite a bit to allow this game to play on a large range of hardware. Even on maximum settings, the XPS 15 does very well.
GPU Conclusion
It’s great that we just reviewed another GTX 960M powered laptop, but it had the 4 GB version of the graphics card rather than the 2 GB version that Dell is shipping in the XPS 15. Despite half the memory, the graphics performance is pretty much even. It doesn’t seem to be a huge disadvantage with the games that we tested in any case. With higher resolutions, such as gaming at UHD resolutions, it would likely make a bigger difference, but the GTX 960M is already showing its performance limits at 1920x1080 gaming, so asking it to draw four times the pixels is likely a bit much.
Compute
The XPS 15 is not marketed as a gaming laptop, and while any gaming laptop can pull double duty, people buying the XPS 15 may not be interested in gaming at all. The GPU can still be leveraged for certain workloads such as photo and video editing. The parallel computing power of the GPU makes it a great choice for these types of tasks.
CompuBench
The only other device we’ve tested with Kishonti’s CompuBench is the dGPU version of the Surface Book. I felt it would be a nice comparison to see just how much more performance the GTX 960M would give in compute tasks. Compared to just integrated graphics, there is a big jump in performance from both of the discrete cards, but the GTX 960M is roughly double the performance of the GT 940M in the Surface Book. If you need compute power, you get a lot more in the XPS 15 with the quad-core processor and much more powerful GPU.
Storage Performance
Dell does offer the XPS 15 with a mechanical hard drive as the baseline option, but once you step up a couple of tiers it can be outfitted with a PCIe based SSD, and in the case of our review unit it is the Samsung PM951. This has become incredibly popular it seems, since it lets companies check the box beside PCIe on storage, but unfortunately it is a TLC based drive so write speeds aren't as high as what we've seen MLC-based PCIe drives do. Clearly Samsung is aggressive with the pricing on this drive since it is in pretty much every device we’ve seen that has PCIe storage.
Recently PCMark 8 updated their testing for storage to better differentiate drives with NVMe storage. As such, the existing scores are no longer comparable with those from the new suite. The XPS 15 scored 5036 in the new test, but we'll need more devices tested in order to have something to compare it to.
Despite the TLC NAND, Dell shipped the 512 GB version of the XPS 15, so it has enough NAND dies to help the write speeds through parallel work, keeping even this slower TLC drive performant over short bursts. I actually expected read speeds to be a bit higher as well but over 800 MB/s is still faster than what SATA drives can do.
Display
Dell offers two displays on the XPS 15. The base model is a 1920x1080 IPS panel. It’s likely reasonable for most people, but for this review Dell configured out review unit with the upgraded 3840x2160 (UHD) display. This is more than just a resolution bump too. The UHD display also has a backlight which can cover 100% of the Adobe RGB color gamut, or so Dell claims. The standard offering is sRGB only, and the Adobe RGB color space is quite a bit larger, offering more saturation in colors.
However, the majority of the web and most consumer-grade applications are made for the sRGB color space only, so if you use an Adobe RGB display with sRGB as the expected color space, you’ll get an oversaturated image. Display manufacturers combat this by generally offering a way to pick which color space you want to work in. If you are browsing the web, you can choose sRGB, and if you are touching up photos that were captured in Adobe RGB, switch the display to that color space. Dell does this through their PremierColor application on the XPS 15
You can easily switch between the color spaces, as well as several others including DCI-P3 (though I would be somewhat surprised if it could hit it at 100%) and Rec. 709 (which is functionally identical to sRGB), depending on what you are working on. If you open the advanced features, you can tune the color temperature, gamma, and black levels as well. If you don’t have color calibration hardware, this is a quick and dirty way to adjust the display to make it more pleasing.
While we’re in here, Dell also offers another cool feature with this software. They call it the Display Splitter, and its basically an improved version of Windows Snap. You can pick how you want to segment your display, and then when you are dragging windows around, the Display Splitter image will appear. Put the window on the box you want, and the software automatically resizes it and snaps it to the correct location. This is pretty great, and Microsoft should take note of this and work with Dell to get it added to Windows.
Back to the display though, there is sometimes some misconceptions that a display that covers Adobe RGB is going to be more accurate out of the box than one that does not. In fact, it really has no bearing on accuracy at all. What Adobe RGB does is offer a wider gamut of colors, and its up to the laptop manufacturer to ensure that the correct calibration is done to map the correct colors to the display output. To test this, we use SpectraCal’s CalMAN 5 software with a custom workflow. Brightness and contrast are measured with an X-Rite i1Display Pro colorimeter, and color accuracy is tested with an X-Rite i1Pro2 Spectrophotometer.
Brightness and Contrast
The XPS 15 display can get up to 334 nits, which is plenty bright enough for most tasks, and impressive considering the resolution. Good black levels also lead to a contrast ratio over 1000:1, which is respectable. It’s not class leading anymore, but it’s still a good result. For those that are interested, the display will also go all the way down to 13 nits which should be dim enough for working in the dark.
Grayscale
sRGB Grayscale
Adobe RGB Grayscale
Out of the box, the grayscale is not very accurate in either the sRGB or Adobe RGB color spaces. The display has a definite blue cast to it as well, and that plays out in the high color temperature. Gamma is quite good though on both, but Dell should have provided an ICC profile at the minimum to help out with grayscale (or better yet, a calibrated LUT). The UHD display is over a $300 option, so it should be much better calibrated than it is. The color comparator shows how blue the images are.
Saturation
The saturation tests show a better picture than the grayscale though. On both color spaces, the saturation sweeps track nicely all the way to the edges of the gamut. Really only the poor showing on 100% white throws these scores off, with both having an average under 3.0. The images show just how much wider the Adobe RGB space is, and it’s great to see accurate tracking in both modes.
Gretag MacBeth
The most comprehensive test is the Gretag MacBeth, which tests an assortment of colors all over the spectrum. It has quite a few flesh tones tested as well. The XPS 15 does ok here too, but is certainly let down by the inaccurate grayscale results.
Calibrated Results
Luckily the biggest issue with the XPS 15 display is grayscale, and that is the one thing that can be adjusted through calibration. I ran the calibration on both the sRGB space and the Adobe RGB space. This had a much bigger impact on the GMB and Saturation scores than normal, since it was the inaccurate grays that were impacting the scores the most.
In sRGB mode, the Delta E for grayscale dropped to 1.6, saturation accuracy was 1.33, and GMB was 1.61, all of which are much better scores than the uncalibrated results. Adobe RGB had an even better grayscale Delta E of 0.9, saturation of 1.0, and GMB of 1.2. Once calibrated, this display is highly accurate. It’s just too bad that Dell didn’t take the time to calibrate it at the factory.
Other than the grayscale issues, the UHD display in the XPS 15 is quite good. It’s great to see more devices starting to offer wider color gamut support, and Dell was good enough to include software to switch the color space as needed.
Battery Life and Charge Time
The XPS 15 is available with two battery sizes. If you opt for the base model, it comes with a 2.5” SATA drive and a 56 Wh battery. If you opt for a device with the M.2 SSD, the extra space taken up by the 2.5” drive is replaced with more battery cells, giving you 84 Wh of capacity. It also adds about 0.5 lbs of weight to the device, but if you are going to be working away from an outlet, the SSD model should give much better battery life.
But, with the high resolution display, and wider color gamut, battery life is going to take a hit compared to something with a more traditional display. Since Dell sent us the UHD model, that’s the one we have to test.
To test battery life we have two tests. The light test involves light web browsing, with the display set to 200 nits brightness. The heavy test increases the pages loaded by the browser, adds a 1 MB/s file download, and includes movie playback. All testing is done with Edge as the browser.
Light Battery
The XPS 15, with its quad-core CPU and high resolution display, can’t keep up with the best devices for battery life, even on light usage. At just under 7.5 hours, it is well under the XPS 13 and Surface Book results, despite the larger battery. It is also below the XPS 15 9530 results, and that device has a 91 Wh battery and 3200x1800 display.
Heavy Battery
With the extra CPU workload, as well as constant network use, the battery life falls to just 4:23. This is exactly the same as the XPS 15 9530 score, so there is certainly some more efficiency because the display is higher resolution and the battery is slightly smaller on the new 9550 model. It’s still not a great result though.
Normalized Battery
By removing the battery size from the equation, we can get an overall feel for platform efficiency. The XPS 15, despite the higher resolution display, does outperform the XPS 15 9530 on the heavy results, but the UHD display certainly hurts it compared to other devices. The Surface Book with discrete GPU is over double the efficiency, but with a dual-core processor. The Lenovo Y700 has the same processor and GPU, but a much lower resolution display, and it comes out quite a bit ahead of the XPS 15. For those that are normally plugged in, the UHD display is fantastic, but be warned, it’s a big hit on battery life.
Charge Time
The other side of battery life is how long it takes to charge. With an 84 Wh battery, this is a significant amount of capacity to top up. Luckily Dell ships the XPS 15 with a 130-Watt power adapter.
At 148 minutes, the XPS 15 charges very quickly. At least with the less than stellar battery life, once you do plug it in, it gets back on its feet pretty quickly.
Wireless
The average laptop these days comes with a wireless card which can transmit and receive two spatial streams at once, and when it’s used with 802.11ac, that gives a maximum connection speed of 866 Mbps. The XPS 15 comes with a Broadcom wireless card which is 3x3:3, meaning it can work with a third spatial stream and has 50% more bandwidth available, which gives a maximum connection speed of 1.3 Gbps. Although on paper this is higher than Gigabit Ethernet, wireless rarely gets close to its maximum transmission speed whereas Gigabit Ethernet does. But assuming you have a router capable of 3x3 Wi-Fi, this solution should have a better shot of coming close to Gigabit Ethernet.
The XPS 15 sets a new AnandTech record on this test, beating out the Intel 8260 that only just jumped ahead on the last review. But to be honest I was expecting a bit better, if only because the 2x2 Broadcom solution could already hit 500 Mbps, so I was sort of expecting this to be over 700, but it’s still a good enough result that I didn’t feel like I needed to connect Ethernet when I was moving large files around on it, which isn’t something I can say about most laptops.
Thermals
When it comes to thermal considerations, shrinking the 15.6-inch form factor down, but still using higher performance (and therefore higher wattage) parts could be a concern. The CPU thermal design power is 45-Watts, and while NVIDIA doesn’t disclose the mobile GPU TDPs, it’s likely around 60-Watts or so. In most cases, GPU intensive workloads are not too hard on the CPU, and that’s true the other way as well. Laptop gaming, for instance, is very heavy on the GPU but generally not as taxing on the CPU, so in most scenarios Dell won’t have to remove the entire combined TDPs of both parts.
To test the CPU performance with a heavy and long duration workload, I logged the frequency and temperature of the CPU while running the x264 benchmark, which takes about an hour and runs the CPU near 100% load for the duration. As you can see, there was no thermal throttling at all in this workload, but the CPU certainly got warm, peaking around 84°C.
To test the GPU, I looped the Tomb Raider benchmark for about an hour, logging the GPU data every second. As with the CPU test, there was no thermal throttling of the GPU despite the heavy load and long duration. The GPU temperature never got over 79°C during this test.
Dell did a nice job on the cooling solution for the XPS 15. Despite the smaller chassis, it doesn’t appear to throttle under these workloads.
Noise
The other side of the cooling is noise. It’s an unfortunate side effect that in order to remove the heat, we have to rely on fans, and laptops with quad-core processors and GPUs are going to need fans. As with most laptops, the XPS 15 can disable its fans completely when lightly loaded, allowing quite operation, but once you do start to do some work, the fans slowly ramp up, starting around 36 dB(A) and going all the way up to 41.9 dB(A) on sustained light workloads. The XPS 15 can be silent, but once the fans kick in they are certainly audible.
Under heavy loads, the XPS 15 is, to put it bluntly, loud. I measured 52.7 dB(A) with the SPL meter 1” over the trackpad. This was after the GPU load test, where Tomb Raider was left running for over an hour. As a comparison, the Lenovo Y700 with the same CPU and GPU, and doing the same test, was closer to 44 dB(A) after the hour, and since decibels are logarithmic, that’s a big difference. This is the down side of a slim and light form factor: the fans are louder.
Audio
The XPS 15 has two speakers on the bottom of the laptop near the front. I measured 90 dB(A) from the speakers playing music, which makes this one of the loudest laptops I’ve seen. The sound quality is typical of a laptop, with not a lot of range and a lack of low end response.
Final Words
After everything we've seen so far, what is there to say about the XPS 15? As a pure exercise in style, mimicking the look and feel of the XPS 13 was definitely the right way to go. The same Infinity Edge display allows Dell to squeeze a 15-inch notebook into the space that most 14-inch models take up. The aluminum outside feels great in the hand, but the contrasting dark carbon fibre weave on the keyboard deck makes the keys easier to read, and it also does a better job resisting fingerprints. The soft touch coating makes typing on the XPS 15 very comfortable.
XPS 15 Compared to 15.6-inch Lenovo Y700
The keyboard is roughly (if not exactly) the same as the XPS 13 keyboard, which I liked. The 1.3 mm of travel is kind of shallow for a laptop this large, but overall it is pretty good. There are better keyboards around, but it would not take long to get used to typing on the XPS 15. The trackpad is excellent, with plenty of room to work, and nice smooth scrolling. The Microsoft Precision Touchpad drivers lack some of the customizability of other trackpad drivers, but the gestures available are enough for what I need.
Performance is very good, thanks to a quad-core Skylake processor and a NVIDIA GTX 960M graphics card. This isn’t a dedicated gaming system, but the GPU can hold its own and even allow you to play modern games as long as you are OK turning the graphics down a bit. The CPU performance is strong, although as with the Lenovo Y700, the Skylake quad-core didn’t bring a big jump in performance over Broadwell.
The display shipped on the review unit is the 3840x2160 UHD panel with support for the Adobe RGB color space, but the wider gamut can't make up for the disappointing accuracy out of the box. Once calibrated though, this display can hold its own with pretty much anything out there. Text is very crisp, and colors are very vibrant. It’s a shame that there’s not an easier way to use Adobe RGB, but with more devices starting to support this color space perhaps Windows will work on how it deals with different gamuts. We can hope.
The downside of the over 8 million pixels though is the less than amazing battery life. With a large 84 Wh battery, I was hoping for more than 7.5 hours on our light test, but that wasn’t the case. The efficiency is not fantastic, and it is also hindered by LED backlighting that supports a higher gamut, although we did run our testing on sRGB mode. Overall battery life isn’t much different than the XPS 15 9530 that we tested a while back, despite the IGZO display and latest generation processor. It’s hard to get around driving light through that many pixels. The 1920x1080 IPS panel offered in the base model would certainly help here, though not having tested that model it's hard to say just how much it would help.
Dell didn’t load the XPS 15 down with too much extra software either, which is nice. The Dell PremierColor application is great though, and being able to make improvements to the built in Windows Snap assist is a good move. Much of the time I’m not interested in extra software, but if an OEM can improve upon something that is built in, it’s hard to argue with them adding it in.
Overall, the XPS 15 is one of the sleekest 15-inch laptops on the market. If I was looking to purchase something of this size, the XPS 15 would be near the top of my list, thanks to the excellent build quality, great design, and compact size. When you work it, it does get loud, but the combination of good qualities in the XPS 15 are hard to ignore.