Portal 2 on new iMac - Windows vs OS X

Discussion in 'iMac' started by barefeats, May 19, 2011.

  1. barefeats, May 19, 2011
    Last edited: May 19, 2011

    barefeats macrumors 65816

    barefeats

    Joined:
    Jul 6, 2000
    #1
    Here are the Portal 2 results for Windows 7 vs OS X on the 2011 iMac 3.4GHz with Radeon HD 6970:

    Windows 7 at 2560x1440 = 82.6 fps
    OS X at 2560x1440 = 83.3 fps
    OS X is 0.8% faster.

    Windows 7 at 1920x1080 = 126.8 fps
    OS X at 1920x1080 = 124.7 fps
    Windows is 1.7% faster.

    Advanced Video settings used were: 4x MSAA, Anisotropic 8x, Vertical Sync DISABLED, Multicore Rendering ENABLED, Shader Detail VERY HIGH, Effect Detail HIGH, Model/Texture Detail HIGH.

    Kudos to Valve and AMD for closing the "PC vs Mac Gap" -- at least on one game.
     
  2. AdrianK macrumors 68020

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    Feb 19, 2011
  3. SkippyScud macrumors member

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    May 10, 2011
    Location:
    USA
    #3
    How much system RAM and how much Video RAM on the 6790m?

    I had a very hicup like experience with the i5 3.1Ghz on 4GB RAM and the 2GB 6790m. I upgraded to 16GB system RAM and its smooth as butter at around the frame rate you posted. Just thought this info should be included for those who want to get one of these awesome machines :D

    Plays WoW on Ultra settings with no skipping too!:apple:
     
  4. MythicFrost macrumors 68040

    MythicFrost

    Joined:
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    Australia
    #4
    That's pretty sweet!

    I don't suppose you could tell me how you are getting the frame rate? Are you displaying the FPS via the console or some kind of time demo? I'm wanting to test my 27" iMac (4850M) against it to see the gains. No worries if you don't have time though.

    Cheers
     
  5. barefeats thread starter macrumors 65816

    barefeats

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    Jul 6, 2000
    #5
    That's with 16G system RAM and 2G video ram.
     
  6. Georgio macrumors 6502

    Georgio

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    Apr 30, 2008
    Location:
    Essex, UK
    #6
    I'm curious to see what fps you were getting in OSX Wow @ 2550x1440 with Ultra settings.
    I was getting 30-40 with most settings on low/medium this with a 1GB card.
    I ask as I suspect the card was faulty, going for the 2GB now.

     
  7. Maziar macrumors 6502

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    May 22, 2010
    #7
    nice results and thanks for sharing :)
    I was waiting for a comparison between OS X and Win 7 in games like portal 2
     
  8. NutsNGum macrumors 68030

    NutsNGum

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    Location:
    Glasgow, Scotland
    #8
    Everyone's talking about this game man! Is it that good?
     
  9. iSayuSay macrumors 68030

    iSayuSay

    Joined:
    Feb 6, 2011
    #9
    WHAAATT :eek:

    So 4Gb of stock ram dont enough to get proper fps? Even with 2Gb of VRAM?
    Does gaming really need that much RAM?

    Please enlighten me
     
  10. SkippyScud macrumors member

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    May 10, 2011
    Location:
    USA
    #10
    I will get those numbers for you tonight :) I'm thinking it was the system RAM honestly... before I installed the RAM it was a rather rough frame rate at native res. I moved it to "High" quality and it was better. After the 16GB upgrade I bumped it up out of curiosity and it just swims on Ultra.
     
  11. SkippyScud macrumors member

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    USA
    #11
    No, no game needs 2GB of ram. No PC needs 16GB of RAM either. But for whatever reason (unknown to me, I just game, I don't marvel at how it works too much) it smoothed out my experience. I'm not trying to pretend I know anything technical. But this is what I 'felt' and saw.
     
  12. barefeats thread starter macrumors 65816

    barefeats

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    Jul 6, 2000
    #12
    I'm using the console mode to invoke a recorded game session. When the recorded sequence is complete, console displays the average frame rate for that run.
     
  13. barefeats thread starter macrumors 65816

    barefeats

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    Jul 6, 2000
    #13
    I just installed and ran my WoW GPU test*.

    At 2560x1440, 1x MSAA, and "High" preset, I'm getting 75 FPS on the 2011 iMac 3.4GHz w/ Radeon 6970/2G (running OS X).

    Oddly, under Windows 7, I only get 58 FPS.

    (* Designed in consultation with a WoW programmer, it stresses GPU over CPU. I measure average frame rates using the Titan Performance Addon.)
     
  14. MythicFrost macrumors 68040

    MythicFrost

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    Australia
    #14
    Actually, some games do need 2GB VRAM at 2560x1440+. Especially with high AA and AF, etc.
    Ah, thanks!
    Hmm? Perhaps the 6970M drivers are really poor right now? Are you using the drivers from AMD.com for the 6970M or Apple's?
     
  15. barefeats thread starter macrumors 65816

    barefeats

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    Jul 6, 2000
    #15
    There is a developer tool, OpenGL Driver Monitor, that lets you observe remaining VRAM as you run a game. I observed Portal 2 using over 900MB of VRAM during some runs. I've yet to see it go higher but I have only been running at "High" with 4X AA. Maybe if I go to "Ultra" or "Extreme" settings, it will go over the 1GB mark.

    As for drivers, in the first round of testing, I'm using Apple's Boot Camp driver. Then I'm going to install the AMD drivers to see what difference it makes.
     
  16. jpjandrade macrumors member

    Joined:
    Mar 17, 2010
    #16
    Interesting!

    What about the 6770M (or the 6750M)? They have 512MB of VRAM but run very well with 4x AA, even if it's on 1080p. How is the VRAM usage there?

    Thanks for all this data!
     
  17. MythicFrost macrumors 68040

    MythicFrost

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    Australia
    #17
    Ah yeah, I think highest settings w/ 8X AA and 16x AF would push it over 1GB just a bit.
    Ah okay, that'll be interesting. I have a feeling AMD drivers will be much better :D
     
  18. tsugaru macrumors 6502

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    Feb 9, 2003
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    Edmonton
    #18
    I highly doubt this. Sorry. This is from the same person who states that the 3.4 i7 is slower than the 3.1 i5 in Portal. Another test I'm taking with a grain of salt.
     
  19. Binary Ninja macrumors newbie

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    May 17, 2011
  20. MythicFrost macrumors 68040

    MythicFrost

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    Australia
    #20
    Keep in mind, he's using Apple's Boot Camp drivers not the drivers from AMD which should, in my opinion, perform much better. As he said, he'll be doing a comparison between the two.

    Additionally, the difference between the i7 3.4 and the i5 3.1 is so small (when all cores aren't utilized) that its within the margin of error when doing these kinds of tests. Also, it has been said for a long time that hyper-threading does hurt FPS, although I don't entirely believe that, and put it down to the former.
     
  21. iSayuSay macrumors 68030

    iSayuSay

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    Feb 6, 2011
    #21
    The fact that still annoys me is the RAM. Is it really that 4Gb stock RAM is not enough to achieve the maximum FPS? I thought gaming isn't supposed to be memory hog.

    Yeah maybe amount of RAM could affect loading time, or time when you switching from your game to desktop, apps or so. But dropping FPS?? Wow can it be true :eek:

    Please, if you have time to spare .. do a test using stock 4Gb RAM, no need to repeat all, just one comparison test. Say like testing Portal2 only at 2560 x 1440 using 4Gb stock RAM, compared to 16Gb you used.
     
  22. MythicFrost macrumors 68040

    MythicFrost

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    Australia
    #22
    I believe the problem starts when you're system starts paging. Up until that point, it shouldn't make too much difference. 8GB should be enough.

    I've struggled with 4GB even without running games, just general use it starts paging eventually, etc.
     
  23. barefeats thread starter macrumors 65816

    barefeats

    Joined:
    Jul 6, 2000
    #23
    Corrected WoW results - OS X vs Windows 7

    When I ran WoW under Windows 7 on the 2011 iMac 3.4GHz,
    I forgot to disable vsync. That made OS X look faster.
    Here are the corrected numbers.

    Windows 7 at 2560x1440 = 86 fps
    OS X at 2560x1440 = 75 fps
    Windows is 14.7% faster

    Windows 7 at 1920x1080 = 120 fps
    OS X at 1920x1080 = 107 fps
    Windows is 12.1% faster

    Settings were 1x MSAA and "High" preset.
     
  24. iSayuSay macrumors 68030

    iSayuSay

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    #24
    Now that's more like it supposed to :D
     
  25. tsugaru macrumors 6502

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    Edmonton
    #25
    barefeats:

    any chance you can provide a copy of the timedemo file that you used?
     

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