Introducing: The Fastest Desktop CPU Ever

In the world of PC hardware, there are few certainties. Should you use an Nvidia or AMD video card? Do you want to build on an Asus motherboard, or Gigabyte? Should your SSD be a Crucial, or an OCZ?

One thing is for sure though, and this isn’t likely to change any time soon – Intel makes the fastest desktop CPUs in the world, and have for quite some time. When choosing which CPU to build a system around, if the question is “do you want the fastest one available?” then the answer is always “Intel”.

However, since the launch of Sandy Bridge, there has a small amount of conflict. Because while the Sandy Bridge architecture is extremely quick, it’s technically not the fastest. That billing still belonged to the Gulftown based Extreme Edition models (the latest being Core i7 990X). While they were based on an older architecture, they still won in most performance scenarios due to sheer clock speed, a huge cache, and thread count – 6 cores with 12 logical threads to be exact. It is also the only way to get two full native x16 PCI-E lanes for dual graphics adapter setups.

The problem with these models though, is that they are reaching the limits of clock speed, and the architecture is beginning to show its age (with lack of AVX support and no on-die GPU for blazing fast media encoding). It is also sitting on an older platform that will never see anything from later architecture builds.

That’s why today, Intel is proudly unveiling the replacement to the Gulftown based Extreme Edition CPU, and it is based on the latest iteration of Sandy Bridge. Today, we will be looking at the Core i7 3960X Extreme Edition CPU.

What’s New?

Usually when Intel makes an Extreme Edition processor, it is simply a higher clocked version of existing architecture. For instance, Core i7 980X Extreme Edition was just a higher clocked version of the regular Core i7 970. When the 990X was introduced, the 980X was eventually replaced by a normal 980 with similar specs. That is not quite the case here, as you’ll see.

The CPUs being unveiled today are all a part of the “Sandy Bridge-E” platform, which is still in the “Tock” phase of Intel’s product release cadence. If you recall, “Tick” means they introduce a new manufacturing process, and “Tock” is a refinement of that process. Westmere was the “Tick” introduction of 32nm, and Sandy Bridge is the “Tock” introduction of a new architecture of that process, and Sandy Bridge-E is still part of that. The next “Tick” will occur next year, and will be the introduction of the 22nm process called Ivy Bridge.

So this is what the Sandy Bridge-E core looks like:

And for reference, here is the old Sandy Bridge die:

As you can see, Intel managed to squeeze on some extra CPU cores, at the expense of the GPU core. And if you look very closely, you’ll notice two unlabeled areas where cores should be. Well they are indeed there, but disabled for this batch of processors. It seems that Intel is somewhat undecided on whether to include graphics capability on all their chips, but I think the assumption is that the enthusiast crowd will not be interested in it at all. If you recall, Sandy Bridge was originally launched on a platform that didn’t even support its GPU at all! Quick Sync is still faster at encoding video than any CPU, but it is possible that the very fastest CPUs will be fast enough that you won’t miss it if it’s gone. We’ll find out for sure later in this review.

Other than that, there are just a few more new things. First of all, there are 40 PCI-E lanes, up from a comparatively meager 16 lanes. Although Intel has stated that the CPU “may be” capable of PCI-E 3.0 specs (8 GT/s), it is still considered a PCI-E 2.0 controller on paper. I fully expect to see Sandy Bridge-E motherboards stating PCI-E 3.0 specs however.

Secondly, the dual channel DDR3-1333 memory controller has been replaced by a quad channel DDR3-1600 controller. That gives a HUGE leap in memory bandwidth, but we have seen that the Sandy Bridge platform is not starved for memory bandwidth at all.

And that will be even more so with the third big change to Sandy Bridge-E: a huge L3 cache. The exact amount depends on the CPU model, but the i7 3960X we’re looking at today comes loaded with 15MB of L3 cache, up from 8MB on the highest end Sandy Bridge chip, and 12MB on the previous Extreme Edition chip.

Other than that, Sandy Bridge-E is very much the same as the Sandy Bridge we’ve grown to love this year. No actual core performance improvements have been made, but with four extra threads, higher clock speeds, and gobs of cache, expect it to perform much higher than Sandy Bridge chips.