Hi. I want to upgrade my gpu from a 660 to either a 670 or a 680. I bought a alienware x51 * Greatest Mistake of my life* and I was if i should upgrade from a 660 to a 670 or from a 660 to a 680. The only problem that I have is that if i will get a 680 it will be crammed into the case and i will need to buy another psu since this one only has 330W. I have a two year warrante too so which one would be the better option?
GTX 670 - http://www.asus.com/Graphics_Cards/GTX670DCMOC2GD5/#specifications
GTX 680 - http://www.galaxytech.com/__EN_GB__/Product2/ProductDetail?proID=15
I would get the new GTX 670 mini from Asus, It's small so the airflow will be great. I don't know if it's out yet though.
You couldn't run either of those off of a 330W PSU, especially when overclocking. With my 680 and 3770k, I idle around 390-440W, depending on what background programs I have installed.
For the PSU I recommend getting a Lepa 750W, Seasonic X 750W, or Seasonic G 650W. You don't need more than 550W for most situations with a single GPU, but a 650W or 750W will support future upgrades, and leave room for overclocking. You could probably go CF on a 750W.
I don't recommend a 670 or 680; get a 7970. For the money, it is much better. A stock 7970 can even beat a lightly overclocked 680. You get 3GB of VRAM in the 7970, which allows for higher resolutions, and an all-around powerful card. However, if you are really cramped in that X51, the smallest, and most powerful GPU I can think of, is the new Asus 670 DCII mini. It was in the most recent Tek (51), so you can go check that out. The Asus 670 mini is much shorter than a standard 670/680/7950/7970, and is about as long as an mITX board. However, a 7970, or even a 7950, is a much better choice than a 670 or 680.
This guy here http://www.youtube.com/watch?v=c-gIsR515L8 put in a evga gtx 670 FTW and the minimum psu is 400W he managed to run the gpu?
That would be without overclocking either GPU or CPU, and could cause critical failures if a particularly GPU-hungry application used too much of the GPU power and exceeded the bounds of the PSU.