Hi everyone. I don't have this game on GOG but I bought it on steam and the same speed issue happens with me. I suggest to the GOG support guys that they update their support articles since the power management settings do not always solve the issue and it's not exclusive to windows vista (i'm running windows 7).
I posted what I've researched on the steam forums: [url=]http://forums.steampowered.com/forums/showthread.php?p=19809748#post19809748[/url]
In short: yes, the issue is because the power management features of modern CPUs and the way that UT, Unreal gold and Deus Ex (every unreal engine 1 game, in fact) set the speed of the game using the nominal (max) speed of the CPU. That speed is used as a reference to set the 100% speed of the game. Since SpeedStep (Intel) and PowerNow! (AMD) lowers the CPU multiplier (and its frequency) the game runs slower and with fluctuating speed each time the computer speed the CPU.
A solution is to download CPU-Z and checking the CPU speed while running the game in a window. Then you use the -CPUSPEED=XXXX command to execute your game, setting your CURRENT (not max) frequency in Mhz, and that number will be used as reference for 100% speed in the game. For example, my core 2 duo runs at 2000mhz max, and that's the reference for UT to measure 100% game speed. If I check my CPU frequency with CPU-Z, it says that i'm running at 1196Mhz. Then I use the -CPUSPEED=1196 command and the game is supposed to run at 100% speed with that frequency.
This solution however, doesn't work that well for me, since the CPU frequency is still fluctuating every time the computer feels the need to speed it up, and of course the game speed reflects this.
The ideal solution would be to have the CPU run at its full speed all the time, battery savings be damned. Then you can try to set your power management options as "high performance" and checking in the "advanced" tab so as to have the CPU running at 100% speed all the time.
Sadly not every motherboard is compatible with windows 7 power management drivers, so this not necessarily reflects a change in CPU speed or power management. Such is my case.
You can try to fiddle inside the motherboard's BIOS and disable EIST, C1E, SpeedStep, PowerNow! or whatever setting enables the motherboard to lower the CPU multiplier. If you can, then you're lucky, but if you're using a laptop you should need to change this setting each time you want to play the game, so as to save battery life when you need it.
If after trying all this, unreal engine 1 games still run slowly/with fluctuating speed, then you're on the same boat as me. Power management settings don't change CPU speed in my case, and my BIOS doesn't have options to disable SpeedStep.
Another workaround is running UT with the software renderer. This strains the CPU enough to enable its highest speed, but of course the game looks bad and if you have a super fast CPU then maybe it won't work.
Funny thing I forgot to tell in the Steam forums: One of the first things i tried was to set vertical sync on on the video card drivers and it worked for a while, UT and Unreal Gold ran perfect. Then I tried to run Deus Ex and the issue happened again in the three games. V-sync settings haven't changed and I tried switching them back and forth to no avail. I don't know if I was running some moderately high requirement application in the background or what happened, but it worked for a while and now it doesn't.
Alternative options that I have yet to try are updating motherboard drivers (to solve the power management compatibility issues) and running some application that enables the highest CPU freq while running the game (but doesn't strain the CPU, as Prime95 does). I'll update accordingly.
Post edited December 26, 2010 by Beakman