A Changing Thermal Target: Discussing Haswell

Pat Gelsinger once taught me that a single microprocessor architecture can efficiently target an order of magnitude of TDPs. It's not that you can't scale above or below that range, but at that point it becomes more efficient to use a different microarchitecture.

Let's take Sandy Bridge for example. Current desktop variants of the chip exist at 65W and 95W TDPs and later this year we will see Sandy Bridge E with a 130W TDP. If we pick 130W as the upper bound for the architecture, it should be able to efficiently scale down as low as 13W - or one order of magnitude. Looking at mobile SNB processors, it does.

Intel's ultra low voltage SNB carries a 17W TDP, while mainstream mobile SNB chips are in the 35W (dual core) to 45W (quad core) range. These TDPs all include processor graphics. With Sandy Bridge, Intel has an architecture that spans from 17W all the way up to 130W. I wouldn't be too surprised if we eventually saw some ~13W SNB parts for really low power applications in the future.

At the end of Q1 of next year Intel will introduce Ivy Bridge, its first 22nm microprocessor. I fully expect Ivy Bridge to target relatively similar TDPs as Sandy Bridge, however the initial launch will be confined to TDPs less than or equal to 95W (much like SNB was).

With Lynnfield Intel made it very clear that it's possible to get high-end desktop class performance out of a 95W part. While the 130W chips were still faster, the majority of enthusiast users would get by just fine with Lynnfield. The move to Sandy Bridge highlighted Intel's move away from 130W TDPs for high-end desktop processors and down towards 95W. As I noticed in my transition to a mobile quad-core SNB notebook as my primary workstation, I believe this generation of 130W CPUs will target a smaller portion of enthusiast users than the previous generation. The trend is definitely downward, towards lower TDPs.

Haswell is where Intel's architectures take a dramatic turn. Ivy Bridge is a derivative of the Sandy Bridge architecture, which of course was designed for that 13 - 130W range. Haswell however is a brand new architecture. It'll likely look similar to Sandy and Ivy but its target TDPs will be shifted down. In mobile, Haswell designs will be set at 10 - 20W. That's not the lower bound of the design, just the target for mobile. What does that do to the rest of the scale? Intel presented this slide at its analyst day earlier this month:

In Sandy Bridge, mobile occupied the 35 - 45W range - roughly the bottom third of the architecture's target. Around Haswell two things happen: the mobile design drops and the Atom design target moves upward.

Atom will service a new expanded range from ~800mW to 8W, leaving Haswell to address the ~10W and above market. Multiply that number by 10 and we have our upper bound of 100W - which isn't much different from the 95W we see today for high-end SNB SKUs. That being said, I do believe we'll see a lot more focus around 65W in the desktop.

Meet the Ultrabook Where Does This Leave Atom?
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  • StormyParis - Tuesday, May 31, 2011 - link

    Intel has a history of failing at anything where they don't have a huge headstart (ie, anything non x86, or non purely process driven: Itanium, networks, wireless, DGX, RISC... basically, anything non Flash and non x86, and even x86 they managed to mess up a few times.

    They finally threw in the diversification towel and went all-in on x86. I'm very unclear about what advantages x86 has apart from Intel's fabs. MS dramatically dropping the ball in the phone/tablet space didn't help them at all. MS trying to avoid a catastrophe by going ARM doesn't either. Even if MS finally manages to put together something believable in the phone/tablet space, it won't be an Intel exclusive.

    My new Desktop is a $350 E-350, and is plenty powerful for what I do with it. I'm guessing next year ARM will be at that level of power (basically, playing videos on one screen, office stuff on the other, very light gaming), and it will be a good time to take a long hard look at whether paying $150+ for a Windows license really makes sense.

    I think the weak link int the ARM food chain is Linux: no games, too fragmented, too experimental still, bad documentation. If a good strong and above newb-friendly version of Linux could emerge as a good all-rounder, ARM's chances would be even better. If the Linux camp doesn't wake up quickly, we'll end up with Windows on ARM, which will be... sad.
  • JarredWalton - Tuesday, May 31, 2011 - link

    Generally speaking, all modern CPUs are now RISC, but the x86 processors have an x86 decoding front end that translates the CISC instructions into RISC. Intel did this first way back in the P6 days. Of course, we also have all the SSE, MME, and other extensions (not just from Intel -- all the other CPUs have specialized instruction sets as well for certain work), so I'm not sure how valid calling anything "RISC" is these days.

    I'd also take pretty strong exception with the assertion that Intel has "failed" at networks and wireless; my experience is that both their WiFi and NIC solutions are slightly better than the competition.

    Then we get to the part where you say that an E-350 desktop is "plenty powerful for what you do". I suppose that's great for you, but having used E-350 and a lot of other systems, E-350 would be way down my list for a desktop system. I might use if for an HTPC, but anything more demanding than that and there are far better options. Llano at least is looking pretty good in initial testing, though.
  • Wilco1 - Tuesday, May 31, 2011 - link

    CISC CPUs are NOT RISC, as this is about the instruction set. And they are not the same internally either. CISCs always carry the extra overhead of complex variable length instruction decoders, large micro code ROMs and micro sequencers, extra logic to deal with read/modify/write instructions etc.

    It is for this reason that you can have an Out-of-order RISC (Cortex-A9) which is not only several times smaller than an Atom, but also much faster while using far less power. That's the difference between RISC and CISC.
  • Penti - Tuesday, May 31, 2011 - link

    There's plenty of documentation, games and coherency in GNU/Linux but it is largely so in the embedded and mobile space as ARM doesn't target desktops.

    So a GNU/Linux platform with Gstreamer (Gstreamer and OpenMAX decoders), PulseAudio, GCC toolchain, libraries or middleware such as Clutter, Qt, Android and EGL/DRI/OpenGL ES support does plenty well in the phone, tablet and embedded market with multimedia, applications, user friendliness and games. You have players such as MeeGo, WebOS, Android and low-level infrastructure oriented LiMo. What you don't have and never will have is a consumer GNU/Linux distro that will run on everything from desktop oriented netbooks, desktops and server to phones and tablets. But you already has great games for the GNU/Linux platforms through the mobile-variants. There's no reason you can't use the same tools and API's for full size aka desktop games. For that matter Microsoft will never run Windows (NT) on phones. 8 for ARM I'm sure won't be for desktop users and I'm even more sure you won't be able to install it yourself. Intel however was rather set on running GNU/Linux on x86 tablets and smartphones. That might change now when their partner Nokia decided to go with Microsoft and downsize a profitable company, but I'm pretty sure they don't base their business on that. Different platforms should exist just fine tomorrow too. It's the normal consumers and hardware manufacturers that decides if Windows 8 tablets/smartbooks stick. Just being Windows based and building on ribbon won't do it by it self.
  • Freddo - Tuesday, May 31, 2011 - link

    Looking forward to the fanless Cedar Trail netbooks a lot.

    I hope there will be at least one "quality" model that is released with metal, instead of just feeling like a cheap plastic toy. Oh, and support for HDMI, of course.
  • SteelCity1981 - Tuesday, May 31, 2011 - link

    "Silvermont to look like? I'd say it might look a lot like a modern, ultra low power take on Conroe."

    So that will mean by 2019 the Atoms should have similar performace as the first gen Core I series. :)
  • soydeedo - Tuesday, May 31, 2011 - link

    Does anyone know the model of the laptop in the second picture on the very first page of the article? The picture below the new Padfone.
  • stonedatheist - Tuesday, May 31, 2011 - link

    Yes I do, seeing as how I just ordered one :) it's the Asus Transformer inserted into its keyboard dock.
  • soydeedo - Tuesday, May 31, 2011 - link

    Thanks a lot for the help, and enjoy your new toy. =)

    Very sleek indeed. ASUS isn't playing around these days.
  • Kepe - Tuesday, May 31, 2011 - link

    Yep, the URL to the picture is http://images.anandtech.com/reviews/tablets/ASUS/E... so it isn't that hard to guess what it is ;)

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