Intel Westmere 32nm Launch & Clarkdale Core i5-661 CPU Review

Feature Test: Hyper-Threading (HT)

The Nehalem microarchitecture brought forth the return of Hyper-Threading (HT), which is a feature that was first implemented on the Pentium 4 "Northwood" processors with mediocre results. Thankfully, as we demonstrated in our Bloomfield Core i7 review, this new microarchitecture has really been designed to take advantage of HT's multi-threading performance benefits.

Aside from the lower-end Pentium G6950, all six Clarkdale models feature Hyper-Threading, and Intel is really betting that this a feature that will distinguish these chips from traditional dual-core processors. So is Hyper-Threading's increased multi-threading performance really apparent on Clarkdale? Let's find out with a small selection of multi-threaded applications:

	Intel Core i5-661 - HT Off	Intel Core i5-661 - HT On	Performance Difference
Cinebench R10 64-bit: xCPU	9190	11061	+20%
WinRAR 3.8.0 Compression	287 secs.	255 secs.	+12.5%
x264 HD Benchmark	11.27 FPS	14.25 FPS	+26%
3DMark Vantage: CPU Score	7354	10136	+38%
Far Cry 2	70.11 FPS	82.19 FPS	+17%
World in Conflict	41 FPS	46 FPS	+12%
Street Fighter 4	184.58 FPS	192.46 FPS	+4%

Admittedly our sample size is small, but the results speak for themselves. In highly multi-threaded applications, HT can make a significant difference, speeding up a real-life workloads by 12% to 24%.

As you can see in Far Cry 2, World in Conflict, Street Fighter 4, there are benefits to be had in games since most multi-threaded engines recognize up to four-threads. Multi-threaded games have definitely become more prominent, and we are approaching the point were a simple dual-core processor simply won't cut it anymore.