It is a professional 64 bit Dream machine with supersonic speed! It is beautiful. It is about the ultimate user friendliness. It is about a lifestyle. It is a class apart. You guessed it - I am parroting Apple’s marketing.

For some reason, the performance of Apple’s gorgeous machines has been wrapped in a shroud of mystery. Yes, you could find a benchmark here and there, with one benchmark showing that the PowerMac is just a mediocre PC while another shows it off as a supercomputer, the unchallenged king of the personal computer world.

This article is written solely from the frustration that I could not get a clear picture on what the G5 and Mac OS X are capable of. So, be warned; this is not an all-round review. It is definitely the worst buyer’s guide that you can imagine. This article cares about speed, performance, and nothing else! No comments on how well designed the internals are, no elaborate discussions about user friendliness, out-of-the-box experience and other subjective subjects. But we think that you should have a decent insight to where the G5/Mac OS X combination positions itself when compared to the Intel & AMD world at the end of this article.

If you like a less performance-obsessed article about Apple, OS X and the G5, you should definitely give Anand’s articles in the Mac section on AnandTech a read...

In this article, you will find a pedal to the metal comparison of the latest Xeon DP 3.6 GHz (Irwindale), Opteron 250, Dual G5 2.5 GHz and Dual G5 2.7 GHz.

Scope and focus

Apple’s PowerMac is an alternative to the x86 PC, but we didn’t bother testing it as a gaming machine. Firstly, you have to pay a big premium to get a fast video card – as a standard, you get the ATI Radeon 9650 - even on the high-end PowerMacs. Secondly, there are fewer games available on this platform than on the x86 PC. Thirdly, hardcore gamers are not the ones buying Apples, but rather, creative professionals.

So, we focus on workstation and server applications, especially the open source ones ( MySQL, Apache) as Apple is touting heavily on how important their move to an “open source foundation” is.

The 64 bit Apple Machines were running OS X Server 10.3 (Panther) and OS X Server 10.4.1 (Tiger), while our x86 machines were also running a 64 bit server version of a popular Open Source Operating Unix system: SUSE Linux SLES 9 (kernel 2.6.5). We also included an older Xeon 3.06 GHz ( Galatin, 1 MB L3) running SUSE SLES 8 (kernel 2.4.19) just for reference purposes. Some of the workstation tests were done on Windows XP SP2.

IBM PowerPC 970FX: Superscalar monster


View All Comments

  • Joepublic2 - Monday, June 6, 2005 - link

    Wow, pixelglow, that's an awesome way to advertise your product. No marketing BS, just numbers! Reply
  • pixelglow - Sunday, June 5, 2005 - link

    I've done a direct comparison of G5 vs. Pentium 4 here. The benchmark is cache-bound, minimal branching, maximal floating point and designed to minimize use of the underlying operating system. It is also single-threaded so there's no significant advantage to dual procs. More importantly it uses Altivec on G5 and SSE/SSE2 on the Pentium 4, and also compares against different compilers including the autovectorizing Intel ICC.

    Let the results speak for themselves.
  • webflits - Sunday, June 5, 2005 - link

    "From the numbers, it seems like gcc was only capable of using Altivec in one test,"

    The Altivec SIMD only supports single (32-bit) precision floating point and the benchmark uses double precision floating point.

  • webflits - Sunday, June 5, 2005 - link

    Here are the resuls on a dual 2.0Ghz G5 running 10.4.1 using the stock Apple gcc 4.0 compiler.

    [Session started at 2005-06-05 22:47:52 +0200.]

    FLOPS C Program (Double Precision), V2.0 18 Dec 1992

    Module Error RunTime MFLOPS
    1 4.0146e-13 0.0163 859.4752
    2 -1.4166e-13 0.0156 450.0935
    3 4.7184e-14 0.0075 2264.2656
    4 -1.2546e-13 0.0130 1152.8620
    5 -1.3800e-13 0.0276 1051.5730
    6 3.2374e-13 0.0180 1609.4871
    7 -8.4583e-11 0.0296 405.4409
    8 3.4855e-13 0.0200 1498.4641

    Iterations = 512000000
    NullTime (usec) = 0.0015
    MFLOPS(1) = 609.8307
    MFLOPS(2) = 756.9962
    MFLOPS(3) = 1105.8774
    MFLOPS(4) = 1554.0224
  • frfr - Sunday, June 5, 2005 - link

    If you test a database you have to disable the write cache on the disk on almost any OS unless you don't care about your data. I've read that OS X is an exception because it allows the database software control over it, and that mySql indeed does use this. This would invalidate al your mySql results except for OS X.

    Besides all serious database's run on controllers with write cache with batteries (and with the write cache on the disks disabled).

  • nicksay - Sunday, June 5, 2005 - link

    It is pretty clear that there are a lot of people who want Linux PPC benchmarks. I agree. I also think that if this is to be a "where should I position the G5/Mac OS X combination compared to x86/Linux/Windows" article, you should at least use the default OS X compiler. I got flops.c from to do my own test. I have a stock 10.4.1 install on a single 1.6 GHz G5.

    In the terminal, I ran:
    gcc -DUNIX -fast flops.c -o flops

    My results:

    FLOPS C Program (Double Precision), V2.0 18 Dec 1992

    Module Error RunTime MFLOPS
    1 4.0146e-13 0.0228 614.4905
    2 -1.4166e-13 0.0124 565.3013
    3 4.7184e-14 0.0087 1952.5703
    4 -1.2546e-13 0.0135 1109.5877
    5 -1.3800e-13 0.0383 757.4925
    6 3.2374e-13 0.0220 1320.3769
    7 -8.4583e-11 0.0393 305.1391
    8 3.4855e-13 0.0238 1258.5012

    Iterations = 512000000
    NullTime (usec) = 0.0002
    MFLOPS(1) = 736.3316
    MFLOPS(2) = 578.9129
    MFLOPS(3) = 866.8806
    MFLOPS(4) = 1337.7177

    A quick add-n-divide gives my system an average result of 985.43243.

    985. On a single 1.6 G5.

    So, the oldest, slowest PowerMac G5 ever made almost matches a top-of-the-line dual 2.7 G5 system?

    To quote, "Something is rotten in the state of Denmark." Or should I say the state of the benchmark?
  • Eug - Saturday, June 4, 2005 - link

    BTW, about the link I posted above:

    The guy who wrote that is the creator of the BeOS file system (and who now works for Apple).

    It will be interesting to see if this is truly part of the cause of the performance issues.

    Also, there is this related thread from a few weeks back on Slashdot:
  • profchaos - Saturday, June 4, 2005 - link

    The statement about Linux kernel modules is incorrect. It is a popular misconception that kernel modules make the Linux kernel something other than purely monolithic. The module loader links module code in kernelspace, not in userspace, the advantage being dynamic control of kernel memory footprint. Although some previously kernelspace subsystems, such as devfs, have been recently rewritten as userspace daemons, such as udev, the Linux kernel is for the most part a fully monolithic design. The theories that fueled the monolithic vs. microkernel flame wars of the mid-90s were nullified by the rapid ramping of single-thread performance relative to memory subsystems. From the perspective of the CPU, it take years for a context switch to occur since modifying kernel data structures in main memory is so slow relative to anything else. Userspace context switching is based on IPC in microkernel designs, and may require several context switches in practice. As you can see from the results, Linux 2.6 wipes the floor with Darwin just the same as it does with several of the BSDs (especially OpenBSD and FreeBSD4.x) and its older cousin Linux 2.4. It's also anyone's guess whether the Linux 2.6 systems were using pthreads (from NPTL) or linuxthreads in glibc. It takes a heavyweight UNIX server system, which today means IBM AIX on POWER, HP-UX on Itanium, or to a lesser degree Solaris on SPARC, to best Linux 2.6 under most server workloads. Reply
  • Eug - Saturday, June 4, 2005 - link

    Responses/Musings from an Apple developer.


    They claim that making a new thread is called "forking". No, it’s not. Calling fork() is forking, and fork() makes processes, not threads.

    They claim that Mac OS X is slower at making threads by benchmarking fork() and exec(). I don’t follow this train of thought at all. Making a new process is substantially different from making a new thread, less so on Linux, but very much so on OS X. And, as you can see from their screenshot, there is one mySQL process with 60 threads; neither fork() nor exec() is being called here.

    They claim that OS X does not use kernel threads to implement user threads. But of course it does - see for yourself.
    /* Create the Mach thread for this thread */
    PTHREAD_MACH_CALL(thread_create(mach_task_self(), &kernel_thread), kern_res);

    They claim that OS X has to go through "extra layers" and "several threading wrappers" to create a thread. But anyone can see in that source file that a pthread maps pretty directly to a Mach thread, so I’m clueless as to what "extra layers" they’re talking about.

    They guess a lot about the important performance factors, but they never actually profile mySQL. Why not?
  • orenb - Saturday, June 4, 2005 - link

    Thank you for a very interesting article. A follow up on desktop and workstation performance will be very appreciated... :-)

    Good job!

Log in

Don't have an account? Sign up now