I cant run multiple WoW Clients since I got my 9800gtx

I recently got a upgraded my comp:
9800gtx
2 x 1gb kingston 1066 ddr2 ram

from:
8800gt
1 x 2gb 800 ram (not sure which brand)

I had just started multi-boxing before I upgraded (just got to level 6 on 3 chars), but after I upgraded my clients started screwing up if I try run more than 1.
If i run 2 clients the effects in the background of the loading screen mess up, and if I run three my whole computer lags out and becomes completely unusable.

Im realy sorry if this has already been posted somewhere but i have just spent the last few hours tring to find information on how to fix it and I can't find anything.

Thanks for any help =)

Did you install the latest nvidia drivers? Have you tested your new memory since installing it? Bad memory can do freaky things.

I'm not too clued up about computer hardware but im trying to learn as best I can and would like to become a computer technician in the future. Here is what I would do.
If you still had the old memory, try using it instead of the new memory (If possible and compatable) - I agree with Naysayer test your memory, try find out what is causing the problem. Keep switching components and try single out the problem by using trial and error.
Check your drivers and any software updates for your graphics card and OS. This might be stupid (i'm just trying to help) check if your memory is actually compatible with your other hardware =)

Hope your problem comes right soon and you can get back into the multiboxing action =)

Try running them in opengl (if you're not already)

Right click WoW shortcut and click properties
In the target box add "-opengl" at the end

I recently got a new computer, using 8800GT, and I was getting screen flicker/distortion from 2 copies open. I did this and got it working fine, apart from having to have graphics on medium -> low.

Thanks for the help im going to try now, I don't have the old memory or card and but I'll double check drivers and memory combatiability, then try it in opengl like you sugested

I assume yeh got 2 gigs of main memory and some graphics card.
What operating system yeh got?

One of the things is that once yeh leave the starter area the memory requirement increases, wow dosen't task the graphics card very hard
You might have to drop the res on the game allot and change maxfps maxfpsbk
what I use is maxfps=20 and maxfpsbk=5

try setting wow into windows mode.

if yer running vista yeh need more memory.

I tried updating my 9800gtx to the latest drivers (the beta ones since i already had the latest standard ones) and found no difference, I still couldn't run two clients without the effects screwing up (even in the background of the loading screen).

Next I tried running my WoW in opengl, that fixed it enough that I can now run two copies but now it gets small freezes in the client eg. one of the WoW clients will freeze for a second but the other will continue fine, what is strange though is that it seems to have nothing to do with settings/fps, I can hav 70fps on each client and it will still do it.

I also noticed that when running two clients my 1st and 2nd cpu and both maxed at 100% usage each (even on lowest graphics settings) and that 3rd and 4th aren't used at all.

If I try and run three WoW clients normally or in opengl it still lags out way to much to even be playable (on lowest graphics settings), even though with the 8800gt and 2gb of 800 ram I didn't have any problem running three.

For the person asking about my ram and OS I'll post the rest of my comp specs incase that can help:
ASUS P5K Pro
Intel Q9300 Core 2 Quad 2.5Ghz
Windows XP sp2

but they never changed, the only thing that changed were:
8800gt ==> 9800gtx
2gb 800 ram ==> 2gb 1066 kingston ram

To use the other 2 cores you need to change SET processAffinityMask to 15 in the config.wtf file, for the graphics card issue i had the same problem and it turned out to be set for multiple display performance in the settings;

http://img143.imageshack.us/img143/7120/nvidiaye7.jpg

I tried what you said and it's working much better, I can actually run three clients again with no lag, some strange flickering in things ig but definately playable compared to what I had before.

Thank you so much Carnage and everyone else who gave advice/help, my warlocks thank you all too, we can finally begin leveling again.

P.S. for anyone else who has a problem like this it seemed to be the "change SET processAffinityMask to 15 in the config.wtf file" part that fixed it the most

It will run a whole lot better if yeh get another 2 gigs of memory.