Benchmark : 5870 vs 7950 in Skyrim

Discussion in 'Mac Pro' started by DanielCoffey, Apr 5, 2013.

  1. DanielCoffey, Apr 5, 2013
    Last edited: Apr 6, 2013

    DanielCoffey macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #1
    I received my Sapphire 7950 3Gb Flex OC with Boost from Scan.co.uk (£262.49 inc 20% VAT) today and decided to benchmark it in Skyrim against my Apple 5870. I am very impressed with the performance of this card and feel fully justified in the money I spent on it. I wanted to run all the tests at the 2560x1440 native resolution of my Apple 27" Display rather than the more common 1080p (which the 5870 is much more capable of handling).

    With the 5870 I had to reduce the settings from the recommended High and 8xAA 8xAF down to 0xAA 8xAF in order to get a reasonably steady frame rate but I had a suspicion I was running out of VRAM and this was causing the game to stutter frequently. Even 2xAA introduced significant stuttering. If I left the 8xAA setting on, the frame rate was too low and the stuttering was intolerable. I observed that as AA was increased, VRAM usage hit the 1Gb cap much more quickly.

    As soon as I replaced the 5870 with the 7950, the game experience was as smooth as silk at the same settings so I have been able to increase the settings significantly.

    I wanted to do an "apples-to-apples" test so I took a save inside Dragonsreach and refreshed both the ini files and the Rendererinfo.txt before starting the tests with the 5870. After finishing the route at 0xAA and then 8xAA, I deleted the files again and changed over to the 7950 and repeated the same route.

    The 7950 is not currently flashed for EFI and is running at its stock speed of 860MHz. It is not currently set up to use the Boost to 925MHz 925MHz according to the Sapphire control panel. It is connected to the 27" ACD via miniDP with no adaptor. In Windows it is using Catalyst 13.1 and was recognised immediately on first boot. It runs a few degrees cooler than my 5870 and is quieter under load although I had already replaced the cooler on my 5870 with a third-party triple-fan cooler.

    ==

    System : 2010 Mac Pro, 6x3.33, 12Gb ECC, 27" ACD 2560x1440, 240Gb SSD
    Software : Win7 64 Home in Bootcamp under Catalyst 13.1.
    Textures used : HD DLC, aMidianBorn Book of Silence, SMIM, no ENB.
    Tool used : Skyrim Performance Monitor.
    Mods used : Around fifty mods mainly to do with Immersion such as SkyRe, Frostfall, RND, RLO, CoT and so on.

    Test route : Start in Dragonsreach, exit the door and walk down the steps to the Gildergreen, down to the market, turn right and head all the way down to the front gates, through the gates, walk down the path past the stables to the coach driver and stop.

    I have looked at the GPU load as an average both in the city and out in the wilderness, excluding the time spent zoning. I have observed that the 5870 GPU load is fairly steady whereas the 7950 GPU load fluctuates more widely. I don't know if this is due to texture housekeeping with the VRAM or the drivers.

    ==

    5870 : High, tree and land shadows on, 0xAA 8xAF
    VRAM used : 1009Mb
    FPS : 60 with occasional drops
    GPU load : around 75%
    Experience : Fairly smooth with occasional jerkiness in busy areas

    [​IMG]

    ==

    5870 : High, tree and land shadows on, 8xAA 8xAF
    VRAM used : 1019Mb, limit reached more quickly
    FPS : 35 with frequent stuttering
    GPU load : around 95%
    Experience : Significant stuttering and intolerable jerkiness in busy areas

    [​IMG]

    ==

    7950 : High, tree and land shadows on, 0xAA 8xAF
    VRAM used : 2094Mb
    FPS : 60 and steady
    GPU load : 50% in city, 50% in wilderness
    Experience : Perfectly smooth with no jerkiness, not even near the Gildergreen

    [​IMG]

    ==

    7950 : High, tree and land shadows on, 8xAA 8xAF
    VRAM used : 2098Mb
    FPS : 60 and steady
    GPU load : 50% in city, 65% in wilderness
    Experience : Perfectly smooth with no jerkiness, not even near the Gildergreen

    [​IMG]

    ==

    Having seen that the 7950 could handle 2560x1440 at High and 8xAA 8xAF I decided to change the settings to Ultra but drop the AA and raise the AF. I also set the shadows to High for the time being. As you can see from the following graph, I clearly still have room to push the settings even higher but I also want to add an ENB and I don't want to introduce any stuttering at this stage.

    Oddly the VRAM reduced when I went to Ultra and higher AF.

    7950 : Ultra, tree and land shadows on, 4xAA 16xAF
    VRAM used : 1762Mb
    FPS : 60 with very occasional stutters
    GPU load : 60% in city, 75% in wilderness
    Experience : Very smooth with rare jerkiness in busy areas

    [​IMG]

    ==

    If you have any questions about these tests, feel free to ask but I will not be putting the 5870 back into the Mac Pro. It is relegated to "spare" card just in case of any warranty claim. No it is not for sale.
     
  2. lewdvig macrumors 65816

    Joined:
    Jan 1, 2002
    Location:
    South Pole
    #2
    nice work.

    A really tough game like Witcher 2 set to Ultra would really show a big gap IMO. I'd guess single digits for the 5870.
     
  3. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
  4. DanielCoffey thread starter macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #4
    I am interested in knowing if anyone has thoughts on why the GPU load graph for the 7950 has such swings on it.
     
  5. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #5
    It has room to breath... so it's breathing. The older card is up against a wall... so the curve looks flatter.
     
  6. DanielCoffey thread starter macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #6
    Updated original post - the Sapphire GPU Utility reports that the card is running at GPU clock of 925MHz and MEM clock of 1250MHz at 1.125V
     
  7. ugru macrumors 6502

    ugru

    Joined:
    Sep 8, 2002
    Location:
    Caput Mundi
    #7
    Good Job!

    Great news...my Gigabyte HD7950 3GB Windforce 3 (2X6pin) comes with stock 900 MHz clock....should have similar results....
     
  8. lewdvig macrumors 65816

    Joined:
    Jan 1, 2002
    Location:
    South Pole
    #8
    You need to turn off vsync.

    You are capped at 60.
     
  9. DanielCoffey thread starter macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #9
    Well there is a very good reason why Skyrim is capped at 60... the in-game physics and timescale depend on it.
     

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