I got a Sapphire HD 4670 for Christmas this year. I installed it, updated the drivers, and everything is working fine. I open up TF2, and after a long time of it booting up, I'm finally able to play. I used 1280x1024 at first with full settings on everything, along with AA. I noticed some little lag spikes that only lasted for a fraction of a second. Also, sometimes when I died, it repeated the scene one second before.
So then I tried the game on 1024x768 with max settings + AA. There was no performance boost, but there were still little lag spikes and 1 second playbacks. So then I did that without the AA, and same thing.
Summary: No matter how high or low quality I set my TF2 game, I always get the same performance in terms of FPS but the same lag spikes and playbacks. Is this a RAM issue? I have 1GB RAM right now. So remember, my FPS is great and so is the gameplay other than this little issue. Here's my [awful] specs [though the card is switched out with the HD 4670]:
Yes you are CPU limited, but it seems more like a driver issue to me. I used to play the game with a 3500+, 1GB of DDR-400MHz ram, and the x1800XT. This should be very similar to your setup, though the GPU is weaker. I didn't have any issues like your describing at all. Run Steams defrag tool, that help me with my caching problem. Try using some of the older drivers as well, perhaps your computer doesn't like whichever 8.1x your using.
How often is your PC hitting the hard drive? With only 1 gig of memory, this could cause some pauses and stuttering if the PC has to go to the drive a lot. How full is the drive? Be sure to keep your drive defragged regulary, and if this is the case, another gig of memory can do wonders.
jitpublisher [or anyone else], it takes a while even to open some folders in my computer. Just ordinary ones like My Documents, etc. I'm guessing this is a RAM issue, correct? I ordered two 512mb RAM sticks via NewEgg two days ago. I have four slots, each holding a maximum or 512mb. All four are filled with 256mb sticks now. I guess I'll be getting 1.5gb on this computer. Any noticable difference when upping the RAM by half a gig? I'm planning to order two more anyway, but I'm curious.