Cheap Video upgrade advice

I'm looking for advice on the relative merits a few video cards.

Quick background: I have a Linux machine I use mainly for work, but occasionally play games on it (I have a hard drive with Windows XP specifically set up for that purpose). I mostly play CoX; either solo, doing marketing or messing with costumes. With Power Customization now in beta, I've been thinking I'd like to improve the graphics on this machine to give BABs and co. their due since I'll probably add messing with customization to the list of time sinks.

However, this is an older AGP machine with a 300W power supply and just adequate cooling. Given the life expectancy of the machine and the marginal utility of adding graphics capabilities to a machine not intended - or frequently used - for serious gaming I don't want to spend the money it would take to replace the PSU, cooling and buy a video card. So I'm looking at options for a simple swap from the current nVidia GeForce FX 5200 Ultra in the machine . A card so limited that I'd swear it actually did the "muttley laugh" when I tried to run Neverwinter Nights 2.

The cards I've identified as available and able to be swapped directly for the 5200 under the constraints of my power supply are:

nVidia GeForce 7600 GS
nVidia GeForce 7600 GT
nVidia Geforce 7800 GS
ATI Radeon X1650 Pro
ATI Radeon HD2600 Pro
ATI Radeon HD2600 XT

I know there are other cards that might work, such as older versions of the Radeon 3850, but the GDDR3 versions of the 3850 that I can find eat way too much 12V amperage.

So, basically, I'm looking for opinions on how well these cards work with CoX. Any comparisons with the 7600 GS would be most useful, since I've used that card and consider it the "fall back" upgrade since it's cheap, readily available and uses very little power.

So far the only opinion I've received is that the 7600 GT and X1650 Pro are comparable to each other and better than the 7800 GS (and the 7600 GS, of course).

Your best bet is the 7600GT IMO, followed closely by the HD 2600XT (not the Pro).

The nVidia card will have fewer isues with CoX, but the 2600XT is a fine choice as well, so long as you keep in mind the ATI-specific issues with this game.

Have you checked either cards's Linux performance and compatibility?

Well, I don't do anything serious with graphics under Linux on that machine.

I've used the 7600 GS on Linux (Red Hat and Ubuntu) before at it worked fine. I know at least one person who has used the 7600GT (now has a 7900GT) with Ubuntu. I'm on RH on that machine atm, but I'm sure I can get any of the 7 series nVidia cards to work for what I need.

AMD lists drivers for all the Radeon cards under Linux on their support site. I'm not sure if they actually work though.

Another vote for the 7600GT.

Same. I know several people using 7600GT's. They can't set their graphics as high as I do, but since you don't expect to be doing mothership raids (or even teaming) it should be more than sufficient.

7600gt

Avoid the 2600 series if from Diamond Multimedia.

I know first hand now they are in the habit of undercooling their cards, smallest amount of dust causes issues.

Sounds like a consensus for the 7600 GT, which is what my opinion was before I let my ATI fan friend talk me out of my prejudices (I haven't bought an ATI card since the first version of the All-in-Wonder Pro).

Now if I can just find one with 512MB of RAM (I can only find a 256MB version atm).

Problem is that back then, when the 7600GT came out, it was common that the 512MB version of the card had slower memory, sometimes a lot slower. What you need to look for is a card with GDDR3 memory clocked at 1400MHz instead of DDR2 clocked at 800MHz. The core clock should be 560MHz.

The choice is either lowering your desired resolution, AA setting and texture quality setting; or suffer some unknown amount of penalty due to additional texture swapping; or suffer some unknown amount of performance penalty due to only having 57% of the memory bandwidth to video memory that a DDR3 256MB card has. This if for games in general not just this one.

Of course beggars can't be choosy.

I'm not even sure there is an AGP version with 512MB of DDR3. All I can find are 256MB DDR3 and 512MB DDR2. Since power consumption and heat dissipation are both issues with this machine I wonder which I'm better off with. I don't have power consumption info for the DDR3 card, but in most other cards the faster RAM dramatically increases the juice needed. The slower card I'm sure fits in my energy budget, I may just play it safe and use that.

FX 5200 Ultra 128MB -> FX 7600 GT 512MB DDR2 is still a major upgrade on the graphics. Plenty for just fiddling with power customization I think.

[Edit:]

Looking at the pricing on the DDR3 cards, I'd be better off selling the machine I have for parts and building a new one with PCI-E, and that's more time than I'm willing to spend on this. The machine just isn't worth adding a $140 card to. DDR2 it is.

I reconsidered my various options and bought a FX 7600 GT 512MB DDR2 card today. I just couldn't bring myself to budget the time to do more than a straight video card swap and I couldn't find info on the DDR3 version's power usage.

Thanks for the advice everyone.