Today is the first day of the 2005 fall Intel Developer forum, and it hasn't taken long for the big news to break over the web. Intel has announced their next CPU architecture, and it looks, at least in a general sense, like they are making strides in the right direction.
It is generally accepted, even among Intel employees these days, that the Netburst architecture of the Pentium 4 has run out of steam. We could debate all day long about whether it was ever a very smart architecture at all, but that's beside the point. It carried Intel for several years, and kept them competitive at the least... In some cases it kept them on top of the performance arms race with their chief rival, everyone's favorite underdog, AMD.
After the realization that Netburst was net-bursting with overly high power requirements and barely manageable levels of heat finally sank in with Intel, they went to work in earnest on what would come next. Today we finally get a glimpse of their hard work over the past months, namely a new unified CPU architecture which focuses on higher performance while using less power.
Before any die-hard Intel fans start breaking up the furniture or setting themselves on fire in celebration, keep in mind that Intel is announcing
the architecture now…It will not be ready for release until late next year (current roadmaps say so… I guess it's possible it could be sooner, but I wouldn't bank on it).
Let me introduce you to Merom, Conroe, and Woodcrest. These are the codenames for Intel's new line of processors (We're a bit too far from release for them to have a real name yet...Everyone please pray to whatever computer hardware gods you believe in that they name it something with a bit more spice than Pentium 5). All three will share a very similar architecture, and each will cover a different part of the market: Mobile, desktop, and server, respectively.
What's the new architecture all about, you ask? Well, information is of course relatively thin on specifics at this early hype-announcement phase, but it looks like the new processors will be based on Intel's current mobile Pentium M, with some of the features of the current Pentium 4 built in. Although this might not sound overly spectacular, since they are basically making a highbred of two processors you can already buy...it does solve many of the current issues with Intel's Pentium 4 and server processors (Xeon and Itanium). For the Pentium M, this new architecture will just be an expansion of feature sets, and an overall increase in performance.
The first of the problems this new architecture will solve is with power and heat. Of course, with modern electronics those problems never really go away...but it's possible to hold them in check and still increase performance. Intel has had a rough time with those things lately, and it appears that this new processor will help a great deal.
The new core will have much shorter pipelines, weighing in at 14 stages compared to 31 in the current Pentium 4's. It will also be wider, the new core will be 4-issue compared to the Pentium 4's two. This will actually make it wider...and theoretically give it higher instruction-level parallelism...than the current Athlon 64 architecture. The much shorter pipelines will greatly reduce the power requirements, but will also mean a drop in clock speed. The greater width will most likely more than make up the difference as far as clock speed goes, though... think of this new architecture in terms of efficiency, just the way we currently think of the Athlon 64 or Pentium M.
All of these first processors based on the new architecture will be dual-core, with the Woodcrest getting a bump to four cores a little later (high-end server stuff). They will have a unified level 2 cache shared by the cores, and will be able to transfer information directly between the two cores' separate level 1 caches. This should greatly increase multi-threading performance over Intel's current dual-core offerings…The Pentium D is really just two cores sitting next to each other on the same package, with no way to communicate with each other except over the front side bus.
The new architecture will of course contain all the EM64T functionality for 64-bit operation, as well as an enhanced version of Intel's current speed-throttling technology that allows unused portions of the core to be powered down to further increase efficiency. It will also contain security hardware to prevent hacks like current processors, and virtualization hardware which will allow it to run multiple operating systems simultaneously. It appears that Hyperthreading will not be present in any of the new processors.
And now, a little speculation. I can't say for sure, but I'm skeptical that these processors will release the same way they are being announced now. Although this architecture sounds like multiple steps in the right direction, there has to be some things that Intel isn't telling us about yet. As described, this "new and improved" architecture is very comparable to current AMD processors, and if it isn't going to release for a full year, Intel will likely not gain back any of the ground they are currently losing. AMD is pushing forward, with plans for quad-core chips in early 2007 and even speculation about an integrated PCI-Express controller on the CPU. If Intel doesn't plan better this time around (and they very well might be…we are just hearing the very first info on this new core), they are going to be rushing out a slapped-together quad-core chip in much the same way they did their first dual-core.
All in all, I would say this is a good thing for Intel. The Pentium M is definitely a solid architecture to build on…and finally laying Netburst to rest is the right thing to do. I really feel bad for those who plan on buying Intel processors now or over the next 12 months, though…The choices are going to be rather limited as far as performance goes, although I'm sure they will squeeze every last bit they can out of current architectures. In the end, anything you buy will be a dead end. Intel's new architecture will be a vast improvement over what they will sell you in the next year, performance-wise, in terms of power consumption and heat, and of course in terms of future upgradeability. Only time will tell how things will shake out, and whether Intel has more up their sleeve in terms of this new architecture that might really push back hard on AMD's current lead in design and performance.