Intel's Haswell Architecture Analyzed: Building a New PC and a New Intel
by Anand Lal Shimpi on October 5, 2012 2:45 AM ESTWhen I first started writing about x86 CPUs Intel was on the verge of entering the enterprise space with its processors. At the time, Xeon was a new brand, unproven in the market. But it highlighted a key change in Intel's strategy for dominance: leverage consumer microprocessor sales to help support your fabs while making huge margins on lower volume, enterprise parts. In other words, get your volume from the mainstream but make your money in the enterprise. Intel managed to double dip and make money on both ends, it just made substantially more in servers.
Today Intel's magic formula is being threatened. Within 8 years many expect all mainstream computing to move to smartphones, or whatever other ultra portable form factor computing device we're carrying around at that point. To put it in perspective, you'll be able to get something faster than an Ivy Bridge Ultrabook or MacBook Air, in something the size of your smartphone, in fewer than 8 years. The problem from Intel's perspective is that it has no foothold in the smartphone market. Although Medfield is finally shipping, the vast majority of smartphones sold feature ARM based SoCs. If all mainstream client computing moves to smartphones, and Intel doesn't take a dominant portion of the smartphone market, it will be left in the difficult position of having to support fabs that no longer run at the same capacity levels they once did. Without the volume it would become difficult to continue to support the fab business. And without the mainstream volume driving the fabs it would be difficult to continue to support the enterprise business. Intel wouldn't go away, but Wall Street wouldn't be happy. There's a good reason investors have been reaching out to any and everyone to try and get a handle on what is going to happen in the Intel v ARM race.
To make matters worse, there's trouble in paradise. When Apple dropped PowerPC for Intel's architectures back in 2005 I thought the move made tremendous sense. Intel needed a partner that was willing to push the envelope rather than remain content with the status quo. The results of that partnership have been tremendous for both parties. Apple moved aggressively into ultraportables with the MacBook Air, aided by Intel accelerating its small form factor chip packaging roadmap and delivering specially binned low leakage parts. On the flip side, Intel had a very important customer that pushed it to do much better in the graphics department. If you think the current crop of Intel processor graphics aren't enough, you should've seen what Intel originally planned to bring to market prior to receiving feedback from Apple and others. What once was the perfect relationship, is now on rocky ground.
The A6 SoC in Apple's iPhone 5 features the company's first internally designed CPU core. When one of your best customers is dabbling in building CPUs of its own, there's reason to worry. In fact, Apple already makes the bulk of its revenues from ARM based devices. In many ways Apple has been a leading indicator for where the rest of the PC industry is going (shipping SSDs by default, moving to ultra portables as mainstream computers, etc...). There's even more reason to worry if the post-Steve Apple/Intel relationship has fallen on tough times. While I don't share Charlie's view of Apple dropping Intel as being a done deal, I know there's truth behind his words. Intel's Ultrabook push, the close partnership with Acer and working closely with other, non-Apple OEMs is all very deliberate. Intel is always afraid of customers getting too powerful and with Apple, the words too powerful don't even begin to describe it.
What does all of this have to do with Haswell? As I mentioned earlier, Intel has an ARM problem and Apple plays a major role in that ARM problem. Atom was originally developed not to deal with ARM but to usher in a new type of ultra mobile device. That obviously didn't happen. UMPCs failed, netbooks were a temporary distraction (albeit profitable for Intel) and a new generation of smartphones and tablets became the new face of mobile computing. While Atom will continue to play in the ultra mobile space, Haswell marks the beginning of something new. Rather than send its second string player into battle, Intel is starting to prep its star for ultra mobile work.
Haswell is so much more than just another new microprocessor architecture from Intel. For years Intel has enjoyed a wonderful position in the market. With its long term viability threatened, Haswell is the first step of a long term solution to the ARM problem. While Atom was the first "fast-enough" x86 micro-architecture from Intel, Haswell takes a different approach to the problem. Rather than working from the bottom up, Haswell is Intel's attempt to take its best micro-architecture and drive power as low as possible.
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FunBunny2 - Friday, October 5, 2012 - link
While not a hardware issue (and thus not an AnandTech major venue), I would be amused if one of your writers explored the implications on data storage design (normal form databases vs. traditional files) of small real estate mobile. My take is that small, consistent bites of bytes are required, and will eventually change how data is stored on the servers. Any takers?lukarak - Saturday, October 6, 2012 - link
In other words, "....all cars were trucks....."?BoloMKXXVIII - Friday, October 5, 2012 - link
Very well written article. Other sites should read Anandtech to see how it should be done.Thank you.
All this power saving in idle conditions is great (love the looping of frame buffer idea), but users aren't always reading text on their screens. When these chips are under load they are still going to draw very significant amounts of power. Unless battery technology improves by an order of magnatude I don't see Haswell (or its replacements) fitting into ultraportable devices like phones or "phablets". The other comments concerning AMD are on the mark. AMD is in big trouble. They are too far behind Intel right now and every indication is they will be falling further behind.
silverblue - Friday, October 5, 2012 - link
Steamroller will haul AMD back towards Intel. Not completely, but a lot closer than they have been, and potentially even ahead in some cases. Still, that process deficit has to be painful, as AMD can only win on idle power.I really hope GF don't mess up again, as delays really are costing AMD dearly. Steamroller is a good design, the sort that means AMD can have a cheaper but still decent part, but I fear it'll come too late.
Intel CPUs are looking even more tasty than ever.
overseer - Friday, October 5, 2012 - link
Great Article.Then I sincerely hope AMD can still survive and stride forward in this mobile tide. (R.R. and J.K., you reading this?)
It may look silly but I do like underdogs and their (solid) products, especially when they achieved something with less talents, capital and executiveness.
wumpus - Friday, October 5, 2012 - link
"To put it in perspective, you'll be able to get something faster than an Ivy Bridge Ultrabook or MacBook Air, in something the size of your smartphone, in fewer than 8 years". I can tell you right now, while this architecture is absolutely great on a motherboard, this isn't the right path to the mobile space."Haswell is the first step of a long term solution to the ARM problem." Unfortunately, anandtech is one of the few places left that can call intel on this marketing blather. Intel's ARM problem is that there is no more efficient way to execute instructions than on a in-order, single instruction issue, clean RISC design: all of which are standard features on an ARM. ARM's intel problem is that this limits you to about .5GIPS ([G]meanless indicator of processor speed) compared to over 6GIPS on an all out Intel design.
The choice isn't all or nothing, just that this time Intel choose performance over efficiency. MIPS, alpha, (to a large part) PowerPC all fell to high performance Intel chips that were vastly less complex than current designs. ARM could try to compete with Intel on performance, but if they are lucky they will end up like AMD, and if they can't out design Intel (remember Intel's process advantage) they will end up like MIPS, etc.
The reason this all appears to be built around speed (and not efficiency) can be found on pages 7 and 8 (despite protests listed on those pages). Intel needs to add wider execution paths to try to get a tiny few more instructions out per second, all the while holding even more (than ivy or sandy) instructions in flight in case it can execute one. All this means a much longer path for any instruction and many more things computed, more leaky transistors leaking picoamps, more latches burning nanowatts. All ARM has to do is execute one after another.
I am surprised that they bothered to toot their horn about the GPU. It might beat ARM, but any code that can be made to fit a GPU should be run on an AMD machine (or possibly discrete nVidia board). They have been pushing Intel graphics for at least 15 years, don't pretend they are ever going to get it right.
In conclusion, I want one of these in my desktop. A phone CPU should look much more like an early core (maybe core2) design, maybe even more like a pentium pro.
A5 - Friday, October 5, 2012 - link
If we're going to start a RISC/CISC battle, you should really look at a modern ARM architecture before talking.What you can fit in a phone today isn't going to be what you can fit in a phone 8 years from now (in terms of both TDP and die size).
Getting Haswell-class performance from a 2020 smartphone isn't that far-fetched...you can argue that modern smartphone SoCs are close to the performance of the Athlon 64 2800+ or the Prescott Pentium 4s of 2004 in a lot of tasks.
wumpus - Friday, October 5, 2012 - link
There is a reason Atom is getting creamed in the phone space by ARM. Also the only way TDP is going to change is with major increases in battery technology. X Joules (typically changed to W/hr in battery speak, but why not stick with SI units) means X seconds a 1 W or X/n seconds at n Watts.On the high end, everything that won the war for CISC (namely, Intel's manufacturing skills) is even more true than when they won. There isn't going to be another. That doesn't mean that a chip designed for all out performance is going to have any business competing with ARM on MIP/W. If they wanted to compete on battery life, they would have scaled down the depth and breadth of the queue, not increased it.
Actually, I was ready to go into full rant when I saw the opening. Then I checked that "ultrabook" meant 1.8GHz i3s. It is quite possible (although I still doubt it is a good way to use a battery) to build a chip that will do that and have low power. I just don't think that Haskel is anyway designed to be that chip
FunBunny2 - Friday, October 5, 2012 - link
-- everything that won the war for CISC (namely, Intel's manufacturing skills) is even more true than when they wonIt's been true since P4 that the "real" cpu is a RISC engine fronted by a x86 ISA translator. Intel tried to sell a ISA level RISC chip (twice). Not so hot. But Intel does know RISC. I've always wondered why they used all that transistor budget the way they did, rather than doing the entire instruction set in hardware, as they could have. It's as if IBM turned all the 370s into 360/30s.
Penti - Saturday, October 6, 2012 - link
It was Pentium Pro that switched to a modern out of order micro-ops powered CPU. I.e. P6. It's only the front end that speaks x86. Intel's own RISC designs like i960 ultimately failed and EPIC even more so when it failed to outdo AMD and Intel server processors in enterprise applications. In reality customers only switched to Itanium because they already had made up their mind before there even was any product thus killing at the time more appropriate Alpha, MIPS and PA-RISC processors. But as soon as those where fased out, Intel's x86 compatible chips had already gained the enterprise features that it missed previously and that set those older chips apart.The front end and x86 decode doesn't use that much space in modern processors at all. CPU architecture aren't really all that important it's today largely about the features it supports, the gpu, video decode/processor etc. ARM just made it into the out-of-order superscalar era in 2011 with A9, superscalar in-order in 2008 with Cortex A8. Atom is kinda designed like a P5 cpu. I.e. superscalar in-order, and moves to an out-of-order design next year. Intel's first superscalar design was in 1988.
ARM just needs to be fast enough, it was fairly easy to replace SH3, Motorola DragonBall, i386 design in the mobile space it was even Intel that did it to a large part. And earlier 8086-stuff had already been left behind by that time. Now what's impressive is the integration and finish of the ARM SoC's. It was Intel that didn't want companies like Research In Motion to continue use low-power Intel x86-chips in their handheld devices. That only changes when Intel sold off the StrongARM/XScale line in 2006. Intel has no reason to start create custom ARM ISA chips again as they can compete with them with x86 chips which they spend much larger time to adapt development tools and frameworks for any way. Atom as a whole has a much larger market then XScale had on it's own. Remember that Intel dropped stuff like RAID/Storage-processors too. Having Intel as a Marvell in ARM chips today wouldn't have changed anything radically.