Ok, so I just got two radeon 9800xt's off ebay for these two old comps I have laying around so that they will at least be able to play cs:source. Both of these comps are having problems now that I put the new graphics cards in them.

The first:
Amd 1.25 Ghz
330w power supply
512 ram
radeon 9800xt 256mb

This one is has what i call a tick. It just doesn't run very smoothly at all. Everything will be fine for a few seconds then it will freeze up for a second. Also it gets pretty terrible fps in source (20-30), but I'm guessing thats because of the processor which is going to be replaced with a amd 3200+ shortly. Will replacing the processor fix the "tick" and the bad fps on this computer?

Alright now onto the Second computer
AMD 2800+
250w power supply
512 ram
radeon 9800xt 256 mb

Now let me start off by saying I had a nearly identical setup on another computer except it had a 9600pro instead of 9800xt, and that computer got 70-90 fps on cs:source. However this computer that I just put a 9800xt in gets about 30 fps consistently. I know it should be getting way higher than that, as the 9800xt was a beast back in its day. Is the power supply the culprit in this computers case? If so, would replacing the 9800xt with a 9600pro be enough to get the power usage back down enough?

Note that on both computers I upgraded from a nvidia fx5200 so there should be noticeable improvements. I also used driver cleaner to get rid of the nvidia drivers before installing the new graphics cards. Any help on these issues would be much appreciated.

Amd 1.25 Ghz vs. AMD 2800+ ?

maybe the amd 1.25 is bottlenecking the radeon 9800xt...

Yeah thats what I'm thinking is the problem with that computer because I'm pretty sure the power supply is enough for that setup. Keep in mind I'm talking about two different computers in this with the same grahpics cards and mobos, just different processors. Each one has different problems.

Change power supplies, trust me on this.

256-bit bus cards are power hogs, especially older models. Minimum 400Watts per PSU for both systems.... good quality ones too. Antec make good quality ones at reasonable prices.

I switched one of the 9800xt's out to a similar system as system number 2 as described in the first post except it has a 330w power supply. Its running really strong on that system so the power supply on the 330w system is fine. However, I am using NGO drivers instead of ATI drivers and I think that is part of what is making the difference.

Also I did a power supply calculator for computer number 2 with the 9600 pro and 9800xt. With the 9600pro it says it needs 169w and with the 9800xt it says it needs like 207w. So the 9600pro SHOULD be enough to get the power usage back down to where it should be. However, when I swapped the 9600pro into that comp I'm still seeing **** fps on cs:s. I'm going to try using the NGO drivers on this computer as well and see if it will make a difference, but does anyone else have any other suggestions?