Does an OS influence performance?

Discussion in 'Games' started by tinydancer, Oct 22, 2004.

  1. tinydancer macrumors regular

    Aug 31, 2004
    North Carolina
    Is it resonable to anticipate performance increases with the upcoming relase of Tiger, with regard to gaming? Does a better OS create better system coherence (for lack of a better word), thereby increasing system performance?
  2. Mantat macrumors 6502a

    Sep 19, 2003
    Montréal (Canada)
    Totaly. OS probably represent 90% or more of system performance. For exemple, copying files in DOS is way faster than in windows or OSX. The bigger the OS, the more 'power' the computer has to use to make it work and the less there is remaining for the rest of the applications.

    This is why efficiant coding can give you a much better performance gain than any hardware upgrade. For exemple, I have seen applications running on a old Pentium 2 (dos) which were faster than their 'newer' version on windows. These were very specific piece of software but it prove the point that nothing is more important than how you manage the system memory and the algos.

    Among the things that will make Tiger faster, there is code graphic. This thing by itself should delegate a lot of the graphic management to the video card, freeing the CPU.
  3. bux macrumors regular

    Apr 22, 2004
    hehe, you're funny.
  4. stoid macrumors 601


    Feb 17, 2002
    So long, and thanks for all the fish!
    And you're naive.

    It might not be simpler, and it may take a little longer to start the copy process since you have to type in the file locations rather than navigating the Eplorer/Finder, but since DOS/Command Line doesn't have to deal with all the pretty GUI/Aqua interface garbage, it can copy files faster and with less CPU usage.
  5. vraxtus macrumors 65816


    Aug 4, 2004
    San Francisco, CA
    Yes and/or no.
  6. Mr_Ed macrumors 6502

    Mar 10, 2004
    North and east of Mickeyland
    Apples (no pun) and oranges. What you really mean is that since DOS was not a multi-tasking OS, it dedicated it's ONE thread to copying the file, therefore that operation has less overhead. Never mind that you had to wait for it to finish before you did anything else.

    The overhead I believe you are referring to is more due to the multi-tasking than the GUI. If you initiated a file copy on a GUI front end (such as the Mac's) and waited for the operation to finish (as you would have to in DOS) and did nothing at the UI, you would find the overhead of an idle GUI to be negligible when compared to the fact that the system is multi-tasking and allowing several processes (including the UI itself) to share CPU.

    That aside, modern hardware/OS combinations are far more efficient at I/O than an old PC running DOS was in that they delegate a lot more of the work to the hardware and the CPU never really "waits" on the I/O operation. This means the CPU is free to "do something else" in the meantime.

    Comparing DOS to a modern multi-tasking OS is like comparing the engine in a 1960's VW Beetle engine to a current Porsche flat-six. Sure, the old engine had a lot less moving parts and probably turned a great percentage of the fuel it burned into useful energy, but I know which one I would rather have. :D
  7. Mantat macrumors 6502a

    Sep 19, 2003
    Montréal (Canada)
    I used a software which was mostly coded in assembler, it ran on a P2, the same software, doing the same simple algo is WAY slower on a P4 because it has been recoded in VC++ and the code isnt well optimized. So in this exemple, a 200mhz system is faster than a 2Ghz machine.

    Of course, this is a specific exemple. Want another?

    The other day, a friend of mine had to write a prog to do some sorting to replace an old piece of software writen in c++. He wrote the new class in Java and it was hundredfold faster even if Java is supposed to be slower than C++. Reason? Efficient coding, good use of hashmaps and experience.

    Less and less programmer are taking time now to optimize their code, its so much easier to simply up the specs of the target platform!

    Same thing with company that port games from pc to mac, they dont use any of the specific optimized procs availlable on the mac.
  8. BrianKonarsMac macrumors 65816

    Apr 28, 2004
    as montat says, efficient code is the key. os x continues to be refined in every iteration of OS X, thus it will achieve better performance, but the change won't always be as much as you had anticipated.

    yes you'll see better performance with Tiger, but you'd also see a bigger boost from a better GPU.
  9. Chaszmyr macrumors 601


    Aug 9, 2002
    Anyone who has been using macs for a few years knows how much operating systems effect performance. Jaguar was way faster than 10.1, and Panther was even quite a bit faster than Jaguar. It is yet to be seen how Tiger will compare to Panther.
  10. benpatient macrumors 68000

    Nov 4, 2003
    don't presume that you'll see better gaming performance with a new OS X.

    in fact, depending on how much they use CoreImage in 10.4, it might actually get worse.

    if they improve performance and at the same time increase features/overhead on the same hardware when 10.4 comes out, then well, that means they have been coding for CRAP up until now, and suddenly they've figured out how to be efficient.

    the system OS X is built on couldn't be much more efficient, but everything that is added on top of it will slow it down, not speed it up.

    The only time this isn't true is if new technology takes advantage of once-dormant resources...for example if they find a way to more significantly take advantage of 64bits, dual processors, and latest-generation graphics cards, to use resources that weren't being used, then it can improve performance.

    In general, games aren't going to see much of a change unless they can take advantage of dual processor G5s...which is obviously something only dual G5-equipped machines will do at just upgrading to a new OS won't help directly.
  11. Fukui macrumors 68000


    Jul 19, 2002
    This is so true.

    The problem with OS X performance has more to do with the kernel, the compiler, and frameworks that are built on them, including apps as well.

    As long as apple continues to push more performance out of OS X (there's definitely a ton more they can do - just look at how they nailed start up time with panther). Windows seems quite fast because of how they architected it (many unnecessary services running in the kernel, long time to optimize etc.) that make things "fast"... that and OO designs can slow things down compared to the relatively procedural way things are done on a lot of windows components... that is a design trade-off, but if core-image is any example, expect OS X to get even better in terms of speed.... just look at how fast OS9 is, its incredible how much faster photoshop or some other app is when its the only one active...

    The OS has a huge huge impact on perceved as well as real performance.
    Though of course this is not always true... but just look at the speed of VPC in OS 9 compared to X, its pretty big!
  12. bux macrumors regular

    Apr 22, 2004
    Well, since DOS doesn't support any modern hardware DOS will not be fast at all. I'm not even sure that you can use a SATA hard-drive with DOS...

    Also copying files is a very simple task and since a modern OS supports threads you can have a little more eye candy (at cost of cpu, gpu and ram but not much) without the file copying process gets any slower (It's basically the hardware that limits the speed of that process).

    But back to the main question, yeah the OS influence the performance in several ways.
  13. FelixDerKater Contributor


    Apr 12, 2002
    Nirgendwo in Amerika
    If anyone wants to question what role the OS plays in performance, they should take a look at Amiga.
  14. gekko513 macrumors 603


    Oct 16, 2003
    Does anyone know if OSX even allows a full-screen game to draw directly to the screen? It's possible to activate exposé when in a game, so that leads me to believe that the game has to write to a buffer that the OS flushes to the screen.

    Is this the case?

    If so, is it the same way in Windows XP? And if it isn't, then that would explain a lot about fps benchmarks for games on OSX.
  15. Dr. Distortion macrumors regular

    May 2, 2002
    Eindhoven, the Netherlands
    And you're terribly wrong to think that dos (or macos 8) copies files faster than macos 9/X (or windows 2000/xp)! What happens is that these old operating systems copy files one at a time only, and using very small file buffers. This has one effect: slower data transfers! What happens is that when copying a file a portion is read into a RAM buffer, and then gets written. Especially when copying on the same harddisk this can be sped up greatly by using a larger chunk of copying buffer (say, 16 MB instead of the standard 128K hard disk cache in os 8). Also, when an os copies each file individually, it has to update the volume index each time it's finished copying a file.

    I've also had an experience with DOS where I had to delete a folder containing over 2000 files. It took DOS over 10 minutes to delete all files, because it deleted them individually, updated the volume index, deleted another one, updated the volume index, etc.

    So while the GUI overhead of copying files may be greater on the newer os's than on the older ones, generally the newer os's are much faster than the older os's.

    As of answering the main question: I think Fukui has given a sufficient answer.
  16. benpatient macrumors 68000

    Nov 4, 2003
    Pretty confident that the frame buffer is wiped ou when most Windows games start up.

    since OS X is "always" in control, i'd imagine that CoreImage could conceivably be taking away a good bit of oGL performance from games...

    not that it helps...i've had to hard-reboot my G5 because of game crashes more times than I can even count.
  17. Fukui macrumors 68000


    Jul 19, 2002
    Because you can't get out of full screen right?
    They really need to fix that. There has to be a universal key-combo to break out of a full-screen, even if Apple-Tab is disabled.... I haven't found it yet. Have you tried Apple-Alt-Esc when it crashed? I've found it works sometimes, sometimes it doesn't...
  18. Dr. Distortion macrumors regular

    May 2, 2002
    Eindhoven, the Netherlands
    There is a way to circumvent this: have another mac hooked up to the same network as the "crashed mac"; connect to it with ssh, and kill the game threads... or do a sudo reboot... anything better than having to pull the plug :)
  19. Poff macrumors 65816


    Sep 16, 2003
    Stavanger, Norway
    sooo true.. the machine takes forever to start up again after you've had to turn it off manually..

    any key-combination to bypass this self-check stuff?

    just for the record, alt+option+esc normally works for me when a game breaks in full-screen.

    You can also try to just click the power-button for the Mac to go to sleep. When you wake it again the game might be running.

    And remember to set preferences so that the harddisk spins all the time, even when not used!

    Hmm.. I guess I'm getting a bit off-topic..
  20. benpatient macrumors 68000

    Nov 4, 2003
    I have a 10% success rate with force-quitting games when they freeze full screen.

    The only hard lockups of WinXP I've had EVER have been the direct result of my over-zealous overclocking efforts. ;)

    I may be in the minority in that regard, but there it is.
  21. applekid macrumors 68020

    Jul 3, 2003
    Most games that run in full-screen draw directly to the screen. Two I can think of that don't are Age of Empires and Halo, but I'm not too sure about Halo. Anyways, there aren't very many, and it definitely shouldn't affect performance.

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