No more mysteries: Apple's G5 versus x86, Mac OS X versus Linux
by Johan De Gelas on June 3, 2005 7:48 AM EST- Posted in
- Mac
The G5 as Server CPU
While it is the Xserve and not the PowerMac that is Apple's server platform, we could not resist the temptation to test the G5 based machine as a server too. Installed on the machine was the server version of Mac OS X Tiger. So in fact, we are giving the Apple platform a small advantage: the 2.5 GHz CPUs are a bit faster than the 2.3 GHz of the Xserve, and the RAM doesn't use ECC as in the Xserve.
| Dual G5 2,5 GHz PowerMac | Dual Xeon DP 3,6 GHz (HT on) | Dual Xeon DP 3,6 GHz (HT out) | Dual Opteron 2.4Ghz | |
| 1 | 192 | 286 | 287 | 290 |
| 2 | 274 | 450 | 457 | 438 |
| 5 | 113 | 497 | 559 | 543 |
| 10 | 62 | 517 | 583 | 629 |
| 20 | 50 | 545 | 561 | 670 |
| 35 | 50 | 486 | 573 | 650 |
| 50 | 47 | 495 | 570 | 669 |
Performance is at that point only 1/10th of the Opteron and Xeon. We have tested this on Panther (10.3) and on Tiger (10.4.1), triple-checked every possible error and the result remains the same: something is terribly wrong with the MySQL server performance.
SPEC CPU 2000 Int numbers compiled with GCC show that the G5 reaches about 75% of the integer performance of an equally clocked Opteron. So, the purely integer performance is not the issue. The Opteron should be quite faster, but not 10 times faster.
We checked with the activity monitor, and the CPUs were indeed working hard: up to 185% CPU load on the MySQL process. Notice that the MySQL process consists of no less than 60 threads.
| Concurrency | Dual Powermac G5 2.5 GHz (Panther) | Dual Powermac G5 2.7 GHz (Tiger) | Dual Xeon 3.6 GHz |
| 5 | 216.34 | 217.6 | 3776.44 |
| 20 | 216.24 | 217.68 | 3711.4 |
| 50 | 269.38 | 218.32 | 3624.63 |
| 100 | 249.51 | 217.69 | 3768.89 |
| 150 | 268.59 | 256.89 | 3600.1 |
The new OS, Tiger doesn't help: the 2.7 GHz (10.4.1) is as fast as the 2.5 GHz on Panther (10.3). More importantly, Apache shows exactly the same picture as MySQL: performance is 10 times more worse than on the Xeon (and Opteron) on Linux. Apple is very proud about the Mac OS X Unix roots, but it seems that the typical Unix/Linux software isn't too fond of Apple. Let us find out what happened!
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michael2k - Friday, June 3, 2005 - link
Well, it shouts to stay away from the XServe unless you happen to have vectorizable code that you have the resources to properly vectorize!erwos - Friday, June 3, 2005 - link
Excellent comparison of the platforms, although I actually wish they would have spent more time analyzing the graphs.Like the others, I would have liked to see a G5 / Linux benchmark (now that FC4 has a PPC version, you could run a fairly reasonable one), but I do admit it's not a very popular option compared to x86. My curiosity is whether MacOS X is the problem, or whether it's some sort of issue with the CPU itself. Seems unlikely the G5 would have such a fundamental flaw, but it does shout to stay the hell away from the Xserve until these issues are resolved.
-Erwos
Thresher - Friday, June 3, 2005 - link
As the owner of intel, AMD, and Mac based computers, I have to say this is one of the best and most thorough comparisons I've seen.You did an excellent job of isolating CPU and OS performance.
That being said, if performance were the only indicator, there is no doubt in my mind that AMD would be ruling the roost. However, personal preferences come into play to a great deal. Businesses like the reputation behind intel. I prefer the usability of Mac OS X. People have strong feelings about Microsoft that may color their decisions.
When it comes down to it, performance is important, but not the only reason people buy what they buy. I would say more often than not, the decision is made with only a modicum of logic.
Cruise51 - Friday, June 3, 2005 - link
I'd be interested in seeing how it performs on yellowdog aswell.IntelUser2000 - Friday, June 3, 2005 - link
People, in case some of you misunderstand, the 10.8GB/sec Full Duplex bus means that its two 32-bit 1350MHz bus, rather than one 64-bit bus in the PCs. Its not, 10.8GB/sec x 2 =21.6GB/sec bus, its 10.8GB/sec bus(or more correctly stated 5.4GB/sec x 2). Plus, it says in Apple site that it has TWO(yes two!!!) of the 10.8GB/sec buses, per CPU.Summary: Per CPU=10.8GB/sec
Per Dual Processor System=21.6GB/sec
Johan, about the AMD TDP number, they never state that its max power, they say its maximum power achievable under most circumstances, its not absolute max power.
JohanAnandtech - Friday, June 3, 2005 - link
Porkster: It is a little geekisch Unix joke. Where is your geekish you man spirit?Wessonality: Our next project if we can keep the G5 long enough in the labs.
Ailleur2: indeed, I agree. The G5 is a potent CPU with a lot of potential. Just give it a bigger L2 and a better memory subsystem. This is an architecture that could last very long by applying a few tweaks, like the P6.
Methodical: All of the benchmarks are trustworthy, they should be looked upon as a whole to get a good picture, not just pick one. About After affects, I indicate that the G5 does very well here (seen other reports on the web), I just didn't have the software in the lab.
I also warned that this was not about "should I buy an Apple or not?". It is just "if performance is what counts for me, where should I position the G5/Mac os X combiantion compared to x86/Linux/Windows ?".
StuckMojo - Friday, June 3, 2005 - link
hmph. you say it yourself in the last paragraph...how come you didn't try it?
StuckMojo - Friday, June 3, 2005 - link
yes, it seems you've left out a very good method of testing if OSX is the issue: run a powerPC linux distro with the mysql and apache benchmarks and see what happens!i'd be _really_ interested in the results. see if you can update the article with them.
porkster - Friday, June 3, 2005 - link
"Root Me" in Australian slang is the same as "Fxxk Me" in common language. Some people my find a picture in this review offensive.wessonality - Friday, June 3, 2005 - link
What about installing Yellow Dog Linux on the XServe?