Basically I'm trying to decide between these 2 cards. This is going to be a place-holder for a year or so until I can build a new rig. The most demanding thing it has to do is run World of Warcraft on high settings, maybe SC2 eventually.
Both cards are running in the $65 - $70 range at a local store (Microcenter). The GTS 250 will require a new PSU (I can get a decent one for $30 with rebate). I don't mind spending for the PSU if it's that big of a performance increase. It would be this one unless something else is recommended:
Cooler Master - eXtreme Power Plus 460W ATX Power Supply http://www.microcenter.com/single_product_results.phtml?product_id=0277108
Do I need a new PSU anyway, given that I only have a 300W right now?
Also, the GT240 has 1024MB GDD5, while the GTS 250 has 512MB GDDR3. I have no idea how to compare those stats. Is the GTS 250 still better even with the lower stats?
Next and last, is a new Athlon/Phenom X4 (something like this: AMD Athlon II X4 640 3.0GHz Boxed Processor http://www.microcenter.com/single_product_results.phtml?product_id=0346215)
worth the $100 compared to what I have if I'll just be replacing it in a year? Or will it be enough to plan a build around it in a year? Subjective, I know, but I'd be interested in input.
I wouldn't get the GT 240. It's pretty weaksauce. The VRAM won't make a difference at your resolution. So yeah, GTS 250 would be my recommendation.
The 250 can use 200-250W so yeah I'd get a new PSU.
As for a new rig, I'd go with a quad core. A Phenom II X4 965 is a nice CPU, but I wouldn't get the Athelon X4 at this time. The other thing is, since you're not making the new rig any time soon we're about to see some new CPUs come out from both Intel and AMD, so if you just wait a few months you can get a sweet new rig. Your current CPU is ok. Maybe OC it to help it get along?
One final question: Is the power supply I linked to even enough? In the $400 build they said that Cooler Master's lower end PSU's often didn't put out what they were rated for. Should I consider one of the others? I was hoping to buy one at the local store. How can I tell is the new PSU is really up to the task?
The load range is kinda low and the efficiency isn't to great. 18A on the 12v rail is on the low side. Try to get a psu with that is 80 plus certified. This means that the psu runs at least 80% efficiency. It will make a difference.