Today Intel has lifted the wraps on several processors, including the Core i7 3770K we’re looking at today. Like clockwork, Intel continues their cadence of processor releases, alternating between new CPU microarchitecture, and new manufacturing process every other year. They fittingly(and proudly) refer to this as their “Cadence of Innovation” and we’re reminded of the “TICK… TOCK…” slogan with each CPU that comes out.
2012 is a “TICK” year for Intel, which means the microarchitecture will remain relatively the same as Sandy Bridge, but manufactured on a new 22nm process, down from 32nm.
That doesn’t mean this will be a dull “speed bump” review however – there is actually quite a bit to talk about with Ivy Bridge. Intel has seen this as an opportunity to improve upon Sandy Bridge in quite a few ways (in fact, they referred to it as “TICK+” at IDF), so let’s get right to it!
Core i7 3770K – Ivy Bridge Architecture
The most significant change in Intel’s microarchitecture with Sandy Bridge last year was the huge overall they did on the out-of-order execution engine. That was a “TICK” year however, so we can’t expect similar gains this time around. Instead, the focus has been on the manufacturing process itself, which in some ways is even more impressive, but to the end user, somewhat uninteresting. To read more about the process itself, I recommend you check out BBC’s article. For what matters – performance – stick around.
One thing they have looked at this time around is single threaded performance. From the time it was first introduced, Hyperthreading (the ability to run two threads on a single physical core) has had the potential to actually lower performance when only a single thread is being calculated. This occurs because a single core’s buffer is ‘cut in half’ to provide multithreading, which means they can fill up twice as fast. Ivy Bridge addresses this by dynamically allowing a single core to use as much as it needs to work as if HT wasn’t enabled at all.
Intel also says that they have improved the Floating Point/Integer divider to the point where it has twice as much bandwidth as Sandy Bridge. This should give an overall boost in per-clock performance, depending on the scenario.
Finally, they have tweaked the way MOV operations are performed, so other instructions can be performed while these operations are done on a dedicated part of the CPU. This will further improve per-clock performance.
Aside from that, there isn’t much else to talk about architecture-wise. It still carries four phyisical cores, just like Sandy Bridge. The move to 22nm has brought the TDP down to 77 Watts however, compared to 95 Watts on the 2600K.
We’ll take a closer look at specifications, including clock speeds etc, later in the review.
Core i7 3770K – Improved Graphics in Ivy Bridge
The most significant upgrade in terms of pure performance occurs in the graphics portion of the chip. While Sandy Bridge moved the GPU from a seperate die to sit right on the same CPU die, the performance still wasn’t to the point where it could be used in place of even modest discrete video cards. Although it performed quite well in media encoding (significantly better than expensive AMD and Nvidia cards in fact), it was still pretty much useless for gaming.
The graphics model found on the i7 3770K we’re reviewing today carries the designation “Intel HD4000” and is equipped with 16 execution units, up from 12 within the Intel HD3000 graphics core found on the highest end Sandy Bridge CPU. Interestingly, the HD4000’s maximum clock speed has been reduced to 1150 MHz, while the HD3000 ran at up to 1350 MHz.
Due to the relative stagnation of gaming graphics caused by a long console cycle, this could be a chance for Intel to finally offer viable gaming performance on a CPU… We’ll have to wait and see if that happens later in the review.
On the next page, we’ll take a closer look at the Ivy Bridge lineup. Although this is specifically a review of the Core i7 3770K, some other desktop chips were unveiled today, and it will be interesting to contrast it to Sandy Bridge as well.