EM64T Xeon vs. Athlon 64 under Linux (AMD64)

legrimpeur writes "Anandtech has a nice performance comparison under Linux (AMD64) between the recently introduced 3.6GHz EM64T Xeon processor and an Athlon 64 3500+. It is disappointing to see how the Athlon gets trounced in FPU intensive benchmarks. No memory-bound benchmarks (where the Athlon is supposed to have an edge) are presented, though." Update: 08/09 23:34 GMT by T : As the Inquirer reports, many Anandtech readers take issue with the comparison.

Math Co-Processor

[Anonymous Coward]

Back in the days of 386 and 486 processor, Intel made a math coprocessor to supplement calculations of the cpu to enhance performance. When Intel made the co-processor, they did a good job of embedded calculation in such a way to make them very good in math so good so that Intel decided to patent the idea.

Zip forward to 2000. Now AMD is a formidable threat to Intel's desktop market; however, Intel has a patent on the math calculations piece of the processors limiting AMD's usage of it. I imagine that AMD could license the Math processor circuitry and embed it on the chip at a hefty price but for business reasons didn't or Intel may have declined licensing the Math part.

I wish I had a link to the patent and when it expires but alas... If AMD can get a new FPU technology than AMD will be the front runner

Might have to buy an Intel for a change

[danormsby]

There is a memory test using Ubench in the review here [anandtech.com] and Intel wins again.

So should I save up for an Intel processor or buy 2 AMD machines?

Re:More Slashdot Flamebait?

[callipygian-showsyst]

The editors of Slashdot seem to love posting articles whose sole purpose is to evoke flame wars between Intel fans and AMD fans.

You've hit the nail on the head. Why on earth would you make a statement about how "disappointing" it is that Xeon may be better in some ways? Why is it disappointing to have a CHOICE?

If you don't want CPU choices, get a Mac!

Intel wins, but give credit where it's due

[Epistax]

That's not to say that the Xeon CPU necessarily deserves excessive praise just yet. At time of publication, our Xeon processor retails for $850 and the Athlon 3500+ retails for about $500 less. Also, keep in mind that the AMD processor is clocked 1400MHz slower than the 3.6GHz Xeon.

I think this sums it up (besides the fact Intel kicked their pants). The AMD is running at 2.2 ghz, and retails $500 less. To me this says AMD is working smarter and Intel is working harder. Intel is reaching a (transient) ceiling with their clockspeeds and one day AMD will catch up to it. It will be interesting to see if Intel's multicore plan kicks as much ass as they are presently hoping. It'll also be interesting to see AMDs attempt at the same.

Personally I'm rooting for both. If either company gets screwed, we're all screwed.

FPU intensive?

[klaussm]

Where are the FPU intensive benchmarks that the Athlon is trounced in?

Under normal circumstances a prime finder application does not use the FPU. And I also doubt that the super_pi application uses the FPU. However the powray benchmark (which actually uses the FPU), is one of the benchmarks where the Athlon wins.

So it would seem that it is the Integer benchmarks where the Athlon looses, instead. This also corresponds with how the normal Athlon fares against the normal Pentium.

synthetic benchmarks

[the quick brown fox]

I'm no expert on CPU architecture or synthetic benchmarks, but it seems like most of the synthetic benchmarks they used (primegen, super_pi, TSCP, uBench CPU) are the kinds of jobs that the Pentium 4 architecture is specifically designed to handle well: not much memory bandwidth required, little unpredictable branching. In these situations, the Xeon's 63 percent clock speed advantage is definitely going to make itself felt.

My guess is that if these same benchmarks had been run on any Athlon vs. the equivalent P4 throughout history, the outcome would've been similar. But the results would also have been as irrelevant yesterday as they are today, since we all know the Xeon isn't 40% faster than the A64 in anything like real-world usage.

3.6GHz vs 2.2GHz

[zoid.com]

This is the real compairson. Overclock the AMD to 3.6GHz and see who wins. As soon as AMD gets tthe 90nm process perfected I think we will see a huge boost in AMDs clockspeed.

Hyperthreading

[mcbevin]

While the Intel chip performed well against the AMD one, hyperthreading appeared to perform badly (i.e. the Intel chip without hyperthreading enabled tended to beat the same chip with it enabled).

It would however be interesting to see a test that somehow say ran two of these benchmarks at the same time to see whether hyperthreading had an effect in such a case. Presumably most of the synthetic benchmarks especially don't really favour hyperthreading.

Let's see....

[adiposity]

Xeon = 3.6 GHz, A64 = PR 3500
Xeon = Server, A64 = desktop
Xeon = L3 cache 1MB, A64 = L3 Cache 512K
Xeon = $??? (probably > 800 when available), A64 = $345 (pricewatch)
Xeon = fastest of Intel's 64-bit chips, A64 = slowest of AMD's 64-bit chips

Anandtech = sold down the river? What the hell?

Re:Intel wins, but give credit where it's due

[the quick brown fox]

If Intel's current roadmap [com.com] is any indication, AMD made the right decision and Intel made the wrong one, at least for the long term. They're planning on phasing out the P4 architecture in favor of multi-core variants of Pentium-M, which is a lot closer to PIII than P4 in terms of pipeline length.

You've gotta give Intel credit for having the guts to go all the way with the clock speed thing, though. But then I also applaud them for their daring design with Itanium, even though we all know how that has worked out for them.

Re:indeed

[Bedouin X]

This is still flawed because the AMD model numbers are relative to the class that they compete against. So the 3500+ is supposed to compete against a PIV at 3500 MHz. Just like the Semprom 3100+ competes with a Celeron at 3100 MHz. The Opterons, which compete with the Xeon, don't have MHz ratings they go by pure performance.

Anandtech's claim that the upcoming PIV's are exactly like the Nocona chips are specious if for no other reason than the fact that there would be no reason to differentiate the two.

They should have at least used an FX53 for some semblance of parity.

Re:30 fps is a slideshow

[TheLink]

"The reason our eyes don't have a problem with 24 fps film"

Speak for yourself. When I watched LOTR, whenever they do scenery pans the "screen updates" were damn obvious and jerky - could see the new frames "ripple down".

The fps of film sucks, but the resolution is pretty good.

60Hz isn't enough. 85Hz is just about OK for me (not great but a monitor which does better isn't within my budget). Just use your peripheral vision to look at your monitor (look away from the monitor and see if it flickers at the off-center/edge of your vision) - if you can detect a flicker or unsteadiness then the refresh rate isn't high enough to fool your eyes.

I bet most people can tell the difference between a monitor refreshing at 75Hz and 85Hz. 60Hz for sure. Whether they mind it or not is something else.

Re:indeed

[fitten]

Anandtech's claim that the upcoming PIV's are exactly like the Nocona chips are specious if for no other reason than the fact that there would be no reason to differentiate the two.


Then you haven't followed the differences between Xeons and Pentium 4s. They are basically the same core with differences in FSB, SMP capability, L2 cache sizes, and sometimes the presence of an L3 cache. Otherwise, the core is the same.

In this case, the Xeon in the article is practically the same as existing Prescotts with the exception of having SMP and EM64T enabled.