CPUs Do Affect Gaming Performance, After All

crookedvulture writes "For years, PC hardware sites have maintained that CPUs have little impact on gaming performance; all you need is a decent graphics card. That position is largely supported by FPS averages, but the FPS metric doesn't tell the whole story. Examining individual frame latencies better exposes the brief moments of stuttering that can disrupt otherwise smooth gameplay. Those methods have now been used to quantify the gaming performance of 18 CPUs spanning three generations. The results illustrate a clear advantage for Intel, whose CPUs enjoy lower frame latencies than comparable offerings from AMD. While the newer Intel processors perform better than their predecessors, the opposite tends to be true for the latest AMD chips. Turns out AMD's Phenom II X4 980, which is over a year old, offers lower frame latencies than the most recent FX processors."

Comments

Requires software support, like HyperThreading

[DrYak]

This also shows what many of us have been saying which is Bulldozer is AMD's Netburst.

Yes but not for the reason you think. Netburst introduced two things:
- An extremely deep pipeline, which was a stupid idea and ultimately netburst's demise and core's reboot from the ashes of pentium3. That's the thing most people are referring to when comparing both chips.
- HyperThreading. the ability to run 2 threads on the same pipeline (in order to keep the extremely long pipeline full). That's what's similar to buldozer's problems.

When HT was introduced, its impact on running windows software was catastrophic. That is simply due to the fact that Windows was optimized for SMP (Symmetric Multi Processors) where all CPU are more or less equal. Hyperthreadinng is far from symetric: it introduces 2 virtual processor which must share resource with the real one. You have to properly schedule threads so that no real cpu is idle while a virtual core is strugling. And you have to intelligently schedule threads to minimize cache misses. Windows simply wasn't designed for such architecture and definitely sucked at correctly juggling with the threads and the virtual processors. Proper Windows support came much later (and nowadays enabling hyperthreading under windows doesn't come as much a performance hit).

The "half core" of bulldozer are in the same situation. It's also a weird architecture (although less is shared between half-cores). It requires correctly assigning thread to processors, etc. Again current Windows ( 7 ) sucks at this, you'll have to wait for Windows 8 to see an OS properly optimized with this situation. Until then, the half-core design will come with a huge performance cost.

But that's only in Microsoft world.

On Linux the situation is different. Beside the Linux kernel being much more efficient for thread and process scheduling, Linux has another advantage: opensource code coupled with shorter release cycle. And thus the latest kernels available already support the special core model of bulldozer.

The end result is that bulldozers run much more efficiently under Linux than under Windows (as can be assert from the Linux benchmarks on Phoronix).
And they have decent performance per dollar.

Lets just hope that recent hire of the former Apple chip designer to AMD can right the ship, because otherwise when I can't score X4s and X6s anymore i'll have no choice but to go Intel.

What you'll benefit the most is waiting for a version of windows which does support the bulldozer model.
Although the bulldozer have some short-comings, which are in the process of being ironed out.