Left 4 Dead 2 on Mac Pro (Multicore Rendering)

Discussion in 'Mac and PC Games' started by Amino Man, Oct 7, 2010.

  1. Amino Man macrumors 6502

    Aug 25, 2010
    Why didn't Valve include the Multicore Rendering option in the Mac version of Left 4 Dead 2. This option makes computers like mine (Mac Pro Quad-Core) run the game much faster (60+fps always). Now, on the Mac version I only get 60fps sometimes and mostly 24-30fps.

    Hopefully they build it into an update.
  2. Ace134blue macrumors 6502a


    Sep 17, 2009
    Because it is automatically turned on, its built into the engine. There is no way of turning it off. You get low fps because of OSX drivers.
  3. archurban macrumors 6502a


    Aug 4, 2004
    San Francisco, CA
    with your mac pro, you got only 60fps? ouch. that's wrong. even my sony vaio F gets 70fps max setting. I don't understand why people still try to play games on mac. mac pro is very nice. but if it gets only that fps, don't play game or buy cheaper PC. it's way better than freaking mac.
  4. waiwai macrumors regular

    Feb 24, 2009
    i got the mac pro 2.8 quad with 6gb ram and 5870 gpu...

    i get ~257 FPS max but it spikes down to 50-60 fps when there are a kazillion bodies on my screen...

    most definitely poor drivers... im sure they'll update soon with all these games coming out for Mac...
  5. elmateo487 macrumors 6502a

    Jun 12, 2008
    My story is the same, except a little lower. Mac Pro 2x3ghz 2006, I have a 4890 sound around 200-250, brought down to 40-50 at lowest. Max at 1900x1280
  6. Krevnik macrumors 68040


    Sep 8, 2003
    I wouldn't hold my breath on a quick fix. It isn't like there's a "go faster" switch somewhere in the code they forgot to flip.

    The real problem is that they've been optimizing very heavily towards the type of use the OS puts on OpenGL for the last decade. This is a completely different use than what games do with OpenGL. Because of that, it will take quite a bit of work to find the areas to re-optimize for gaming and communicate this "fast paths" out to developers. The work they've been doing with Valve is only a first step.
  7. neoelectronaut macrumors 68030


    Dec 3, 2003
    Southeastern Louisiana
    Because I don't want to own more than one computer?
  8. Amino Man thread starter macrumors 6502

    Aug 25, 2010
    I used V-Sync (triple-buffered) because I hate screen tearing. That's why it drops to 30fps and 24fps, but in Windows, it's a constant 60fps (triple-buffered vsync).

    I'll put up with lower framerates to keep my screen from tearing. Tearing bothers me more than lower framerates. Besides, the PS3 got me used to 30fps HAHA!
  9. jeanlain macrumors 65816

    Mar 14, 2009
    It's not really built into the engine, rather into the OS X OpenGL framework since 10.4.7. So OS X Source isn't really multithreaded, as opposed to the Windows version. I don't even think that audio runs on a separate thread, since sound will stop in problematic situations even if the CPUs aren't saturated.

    HL2_OSX will not use more than 140-150% of the CPU. I believe the application thread uses one full core (100%), and the openGL thread uses the remaining %, waiting on the main application thread (if it's not waiting on the GPU). Windows, Source will regularly go over 200%. What's more, OS X Source is significantly slower for the same amount of CPU usage (it's still slower if you disable multicore rendering on Windows). This might be due to inefficiencies in the CPU side of the openGL framework and drivers and to the direct3D translation layer they added. Overall, a Source game will be twice slower on OS X if performance is CPU-bound, that is, of you have a slow CPU compared to your GPU and/or low graphics settings.

    Of course, if performance is GPU-bound (slow GPU/high settings), multicore support doesn't matter as much as drivers and openGL optimizations on the GPU side. These appear to be quite good on radeon HD cards, whose performances have improve at lot with the SL graphics update. At high video settings, OS X performance becomes similar to Windows. On the opposite, radeon X1XXX drivers appear to be quite bad. I believe Nvidia drivers could be better.

    RBarris over at the Steam forum insinuated that they will be looking at "true" multicore support on the Mac sometimes in the future, but said nothing really concrete on that matter.
  10. Nermal Moderator


    Staff Member

    Dec 7, 2002
    New Zealand
    Exactly. I don't own a Mac for gaming, but I like being able to play the occasional game (or in the case of WoW, significantly more than occasional ;)).
  11. jeanlain macrumors 65816

    Mar 14, 2009
    I wonder how you achieve 200-250 fps, unless you're on bootcamp. I have the 2.66 GHz model with plenty of RAM and I never achieve more than 90 fps, and that's with shaders on medium. I have a slightly slower GPU (4870), but that shouldn't matter anyway as my performance is CPU bound. I should get 2.66/3 = 88% of your frame rate.

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