AMD Athlon 64 & Athlon 64 FX - It's Judgment Day
by Anand Lal Shimpi on September 23, 2003 1:25 PM EST- Posted in
- CPUs
32-bit vs. 64-bit Performance
Our entire benchmark suite to this point has been on 32-bit applications under a 32-bit OS, mostly because there are no good desktop 64-bit applications at this point in a popular 64-bit OS (not to mention the issues with 64-bit Windows XP we described earlier).
Under Linux however we don't have to wait for applications to be released in a 64-bit version, we can simply recompile them. Linux would thus provide us with an excellent venue to see the tangible performance increases from exposing the additional general purpose registers in 64-bit mode.
We ran all benchmarks on Red Hat Enterprise 2.9.5WS (Taroon), a beta release, booted in single user mode to avoid system services interfering with benchmark results. Neither Red Hat 9 nor 9.0.93 Beta (Severn) supply a 64-bit compiler or libraries, which is why we used Taroon.
The Taroon kernel initially had issues on startup requiring us to disable APIC and ACPI support to get it to install. Once actually running the OS was quite stable however DMA disk access was disabled for some reason.
We used the following compiler that came with Taroon:
gcc 3.2.3 20030502 (Red Hat Linux 3.2.3-16)
And the following kernel:
2.4.21-1.1931.2.393.ent
With this compiler and kernel we ran the following tests:
Whetstone
A simple C loop measuring floating point performance, configured to do double precision calculations.
Compiled with:
-O3 -msse2 -mfpmath=sse (and -m32 for 32bit, -m64 for 64bit)
The performance improvements due to 64-bit are in the 10 - 20% range we mentioned earlier.
Bytemark
An old integer CPU benchmark (FP results were discarded) - for more information on the tests visit this site.
Compiled with:
-O3 -msse2 -mfpmath=sse (and -m32 for 32bit, -m64 for 64bit)
Here we do see a small 2% drop in performance when moving to 64-bit in one test, however the rest of the tests show a 0 - 15% improvement across the board.
Lame 3.93
A MP3 encoder; encoded a 40minute .wav file (403MB).
Lame args: -b 192 -m s -h --quiet <file> - >/dev/null
(192kbps, simple stereo, high quality, output to nothing to avoid disk hits)
Compiled with:
-O3 -fomit-frame-pointer -fno-strength-reduce -malign-functions=4 -funroll-loops
-ffast-math -msse2 -mfpmath=sse (again, -m32 for 32bit, -m64 for 64bit)
The performance improvement here is astounding - in 64-bit mode the Athlon 64 FX managed to finish the encode 34% quicker than in 32-bit mode, if these results are any hint of what could be in store for Windows users, there's a lot of promise behind the Athlon 64...assuming we get software support in time.
We wanted to do a transcode benchmark but that didn't work out - one library found a bug in gcc and transcode refused to compile. It actually forced a compile error because a structure came out padded, meaning they didn't expect anyone to run it on a 64bit machine just yet.
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Anonymous User - Tuesday, September 23, 2003 - link
#38, Huh how heck are we forgetting something NO ONE KNOWS? Has Intel ever really givin an absolute upper limit to the Prescott clocks throughout the year? Last time I heard Tejas would takeover after 4.2Ghz.Anonymous User - Tuesday, September 23, 2003 - link
LOL, you all who think that intel is the winner here, just continue to believe so, but don't tell anyone.If Prescott was so great we should have seen "leaked" benchmarks by now. I saw benchmarks of the Clawhammer more than a year ago.
AMD can not outperform intel because they'll get problems with their supply. That's one of the main reasons AMD don't want to release a cpu that will beat all intel offerings. Imagine what will happen if everyone wants an AMD.
Anonymous User - Tuesday, September 23, 2003 - link
#35, Dude just frigging be quiet as I seriously hope you aren't saying crap like that in public.Anonymous User - Tuesday, September 23, 2003 - link
You guys are forgetting Prescott is capable of 4.6 GHz, and it'll have the price advantage.Anonymous User - Tuesday, September 23, 2003 - link
So what's the difference between 32bit with 64bit extensions, and 64bit with 32bit compatible mode.Anonymous User - Tuesday, September 23, 2003 - link
#29, Didn't Intel reps at IDF make comments to the tune of a 3.2Ghz P4EE offering up better overall performance than a 3.2Ghz Prescott? How heck is Prescott going to change things when it's debutting at 3.4Ghz and going to be up against an FX51 and A64 3400+ (possibly even FX55)?!!?? What part of that shows Intel sailing through 2004 when Prescott is expected to max out at around 4Ghz and A64 hasn't even gone through a die shrink and is already performance competitive with it from the initial 130nm A64 releases??!?Anonymous User - Tuesday, September 23, 2003 - link
Athlon64 isnt running in 32bit compatibility mode. It's still a 32-bit processor with 64-bit extensions, not the other way around. Pure 64-bit processors will trounce it in 64-bit apps.Just keeping up with Intel isn't enough, they needed to take the performance crown without any doubt to really gain back marketshare, right now this is just good enough to tread water, especially considering their pricing. How the next year plays out will be interesting though.
Anonymous User - Tuesday, September 23, 2003 - link
#32Wait till next year when the bugs of 64-bit drivers/software come onto your system. It will be Windows 95 all over again. AMD64 is an expensive disappointment.
THE END
Anonymous User - Tuesday, September 23, 2003 - link
amiga owns you.Anonymous User - Tuesday, September 23, 2003 - link
For everyone saying that the Athlon64 was NOT the so-called AMD Killer, I just have one question:How can you say a 64-bit processor running in 32-bit compatibility mode that keeps up with the best Intel processor, the P4EE, disappointing? Me, I'm waiting for some more 64-bit programs to judge the strength of the Athlon 64. The fact that the Athlon 64 can keep up and sometime pass Intel in 32 bits is awesome.
BTW, I'm not an AMD fanboy. I have both AMD and Intel processors. But I find the Intel zealots are trying to discredit this processor by insisting on only looking at half the picture. Just my opinion.