Unlimited Phenom vs Unlimited Yorkfield

WE'VE SEEN a bit of Phenom's performance in the first part this past Friday - how about pushing it a bit further?

This round, I tuned the Phenom 9900 - unlocked CPU, keep in mind - test setup as far as possible within an extra day for fully stable operations under both Windows XP 32-bit and Vista 64-bit, and ran it against a fully tuned Intel QX9770 setup in an "AMD Best vs Intel Best" approach.

One may say that it's not fair since Intel's CPU is more expensive, however, on the other hand, the AMD one can't be bought at all for some time to come.

Both AMD and Intel configurations used dual Asus EAH3870 TOP cards in both default and Crossfire modes, and identical Windows and Catalyst driver versions - so, as much of an apples-to-apples comparison as possible.

Besides the usual 32-bit benchmarks, the 64-bit run added CineBench10 and PovRay 3.7.

The Limits

This is where the Intel and AMD configurations differ in 32-bit and 64-bit modes: Intel could do 4.27 GHz (multiplier 10, FSB1708) in both modes, but the voltage needed for the 64-bit mode was 1.425 volts vs 1.40 volts for the 32-bit mode, if all tests were to complete.

When using Asetek Vapochill freeze cooling, the limits are 4.6 GHz FSB1840 at 1.45 volts Vcpu in 32 bit mode, and 4.5 GHz FSB1800 at 1.4625 volt Vcpu in 64-bit mode. However, this test run only uses the results obtainable on the usual high-end air or water cooling.

In the AMD case, the absolute limit on my setup with similar air or water cooling was 2.88 GHz (14 x FSB206) at 1.325 volts CPU in 32-bit mode, and 2.80 GHz (14 x FSB200) at 1.337 volts CPU in 64-bit mode for a complete test run. Even then, though, the PCMark Vantage 64-bit run couldn't be completed.

The push to 1.35 and 1.363 volts didn't give any improvement except more heat, so there was obviously no point trying harder.

I didn't really bother to push the memory too much here beyond reasonable latency tuning, as CPU speed is the obvious focus of the story - Phenom has no problems with memory performance, as in Sandra cases it still has a slight 10% - 20% advantage in synthetic memory subsystem speed runs over the Intel offerings.

However, even after accounting for its L3 cache exclusivity, Phenom still has only one-third cacheable data size compared to the dual-die Yorkfield and that seemingly more than neutralises its on-die memory controller advantage.



Source : http://www.theinquirer.net/gb/inquirer/new...ions-amd-phenom

ek

This post has been edited by Evilkyro: Jan 2 2008, 05:33 PM