OK, So my new x58, gtx 480, i7, w7 machine rips. BUT trying to play UT online has been frustrating. It seem that UT dosen't like my computer and I was hoping to find someone that understands the technical issues behind the poor performance. This is what I have done so far to improve gameplay:
 
Installed UT in xp sp2 mode.
Installed the 436 patch
installed the Leatrix Fix (addresses server - client data)
Have all the latest hardware drivers
Have the latest opengl render config
start the game then Ctrl/Shift/Esc to the task manager and set the priority to High, then set the affinity to 1 core, return to the game.
 And still have poor performance, my isp provides 20+ MB download and 4.5 MB upload speeds with a ping in the 90s. The problem I encounter is that my player is slower and/or has a lower priority than many other players. I was hoping to edit the gigbit network card or perhaps it might be the video settings. All I hear from the UT community is that UT dosen't like the gtx 480 or the i7 quad core prosessors or win7.
 
Any thoughts?
Win 7
CoolerMaster 932
EVGA x58
EVGA GTX 480
Corsair Dom 6GB
Ultra 1050 PS
WD Blk 500GB
Plextor DVD/CD
CoolerMaster V8 CPU Fan
I7 930 3.998GHz
 
RotGrub
 
 
 

Well, to rule out problems with the server you are playing on and the entire network config, you could try creating a server (not dedicated) or playing a practice session to see if the issues come up there. If so, then there is something wrong besides the network config. If that works fine for you and only playing online causes problems, disregard the rest of this post because you definitely have a different problem from the one described below.
 
I had an odd problem trying to play this on my older laptop. I would get gamespeed issues due to the power saving features on the CPU. Disabling these features (C1E, speedstep) would have worked, but the BIOS didn't have an option to do so. My solution was to prevent any of them from activating by running prime95 on 1 core while playing. This kept the CPU in the maximum performance state and the problem was fixed.
 
I just tested the game on my desktop (specs in sig) without problems. I don't need the prime95 workaround for it to work since I disable C1E and speedstep anyway.
 
Not sure if you already tried this, but I figured I would mention it since it caused me considerable frustration at the time.