Killab! Do you use a lot of USB-Devices, especially Logitech G5 Mouse or G15 Keyboard? USB seems to be the problem. Do a google search for FEAR and USB and you'll find a lot about the topic. So I tried to unplug my Mouse during the game and TADA, framerate jumped up to 75! Seems it helps if you deactivate some HID devices in Task-Manager. Haven't tried that yet though.

What already improved the situation for me though was the following:

-Unplug all unneccesary USB Devices

-If using a logitech mouse like g5, lower the signalrate to as low as possible in set point

-quit the applications on the Logitech G15 lcd if you are using that

As you can see I tried to take as much load of the USB as possible. I remember also how once I couldn't start condenmed (same engine) unplugging USB stuff suddenly made it possible to start the game.

I read that for someone using XP 32bit on his dual boot system with Vista64 as main os helped a lot as well. So I think I'll give that a try as well since I have such a dual-boot setup too.

check drivers that card should be doing better with fearkemar7856

I think it's pretty much on par with the results of the Guys at guru3d.com http://guru3d.com/article/inno3d-geforce-7950-gt-ichill-editions1m/10

Anyways I am running the latest official drivers. And I have V-Sync turned on which always hits performance and don't me wrong, most of the time ots over 50 and even often hits my refresh rate 75. Still not sure if the Affinity was the solution though. Have to play a bit longer.

Some people with dual cores on GTAIV are getting that problem. It just might be a heat problem. esp if overclocking. Some processors reduce speed if they are hot. That might be it.

Okay, I gave my game another try, this time I had Fraps enabled and watched my system temperatures. After about 10mins I didn't get more than 20fps anymore. Mostly between 10 and 15, not much fun to play anymore. I alt-tabbed out of the game, took a look at the temperature chart, gpu 55 degrees celsius and cpu 40degree celsius, never more during the game. So temperatures were more than fine. But again I noticed how the cpu-load indicators on my G15 display showed strange behaviour. While in the beginning of the game both cores had almost equal load, this shifted more and more to one core.

Now here's the possible solution:

Before alt-tabbing back into the game i started the Task-Manager and set the affinity for fear.exe to just one of the cores. And back in the game, performance was suddenly back to about a general fps of 50 frames or so and almost never below 40. Try that killab!

So any guesses why this is happening? Before I played F.E.A.R. on a Pentium D, now I moved to a Core2Duo an more Ram. The Pentium D is a dual-core as well but I didn't have to fiddle in Task-Manager, it played fine. I also moved from XP Prof. 32bit to Vista 64bit. So this might all be possible causes. Anyone else noticed this problem with FEAR?

well guys, I upgraded my system as I said and now the game runs worse. I think that is reason for concern enough.

Interesting thing I noticed about the problem. When it gets really choppy, and you might think its because of the level, I save and quit, and when I then restart the game and load exactly that save it is smooth as butter again. So there must be a problem somewhere, this is the first game on my updgraded system that I noticed such strange behaviour. It takes about 10mins or something and then the game is choppy. Save, quit, restart, play butter smooth for 5 minutes till performance drops again.

Next step I'll try to keep an eye on my system temperatures.

Well, they said they gonna send out Replacement Discs since the sound in the Wii release has some issues like just being mono.

I heard they started to send them out in the US, but hey, here in Europe we still have no clue at all when they are going to be ready!

Well,

that video you linked was a tech demo simply to demonstrate what the gamecube is capable of before it was out. Nothing more, nothing less.