Added RAM and performance drops in games?

Discussion in 'Mac Pro' started by siorai, Sep 16, 2008.

  1. siorai macrumors 6502

    Sep 14, 2007
    I bought the vanilla octo-2.8 early 08 Mac Pro back in January. (I've since added in the nVidia 8800GT and a couple 500GB harddrives). As many of you know it's a beautiful machine and I've had very few problems with it. I play World of Warcraft and have recently delved into the world of dual-boxing to take advantage of a triple XP bonus currently available. Running two instances of WoW from separate install locations worked fine. But I found that I was hitting a limit. I couldn't really use iTunes while playing without taking a noticeable hit to the games' performance. So I did the logical thing in this situation: I bought more RAM. Specifically a 2GB kit (KTA-MP800K2/2G) from Kingston.

    At first I had them in the wrong configuration. Since the default location for the 2GB that come with the Mac Pro are in slot 1 of each riser, I put the new sticks in slot 2 on each riser. I saw ECC errors and a very odd framerate issue in-game. After about 15 minutes, one instance of WoW would run at 60fps (v-sync is enabled) and the other instance on the secondary monitor would drop to 2-5fps. They would stay like this for about a minute then the framerates would swap: the primary monitor would tank to about 2fps and the secondary would fly up to 60fps. I stopped playing, read up on the RAM placement and found out that the pairs need to be on each riser together. I put the Apple RAM on riser 1 in slots 1 and 2, the Kingston on riser 2, slots 1 and 2. Same story. ECC errors and alternating horrible performance. I then tried swapping the RAM locations and put the Kingston on riser 1, Apple on riser two. I also reset the PRAM as I read that might clear any ECC error issues when installing new RAM. In this setup I had no ECC errors. The framerate issues were still happening though.

    At first I thought it was bad RAM. But when placing them on riser 1 I see no errors. My other thoughts are a bad riser board or overheating. Although I've never had heat problems and the RAM seems to work fine if the Kingston in on riser 1.

    Any other suggestions?
  2. Tallest Skil macrumors P6

    Tallest Skil

    Aug 13, 2006
    1 Geostationary Tower Plaza
    Do they all jive well with the Kingston on Riser A and the Apple RAM on Riser B?
  3. siorai thread starter macrumors 6502

    Sep 14, 2007
    No ECC errors, but I still have the performance issues.

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