Replacing my video card.

[eniced73]

Bought this new EVGA card to replace my old 7600's.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130549

I currently have this PSU

http://www.newegg.com/Product/Product.aspx?Item=N82E16817371007&Tpk=ea500d

I posted in the eVGA forums and two of their moderators think I should be able to run the card with what I have and one recommends not taxing the PSU with the new card. I really do not want to buy a new PSU but I dont want to cause more problems by trying to skimp. What do you guys think? I basically play the old CM games along with ShockForce. I dont play any high end FPS that will push the cards limits right now. Just asking because I really dont know how much SF will push the card. I know it played decent on my two 7600's and the 470 is leaps and bounds above them. The evga forum thread is below. I appreciate any help.

http://www.evga.com/forums/tm.aspx?high=&m=857730&mpage=1#857730

[Schrullenhaft]

I've always been personally confused about the electrical current requirements for video cards and what PSU's will supply on each 12V rail (i.e.- 12V1, 12V2, etc.). Each rail individually has less than the 38A that the video card requires, though it does require to PCI Express power connectors. So maybe it will work. However the CPU is also on a 12V rail, so it may be taking 12V1's current.

Interestingly the industry has gone away from multiple rails for the +12V and have instead gone back to a single rail.

The last poster in the EVGA thread has a point. If you were to add up all of the wattages that the power supply supposedly puts out, then it would be about a 980W power supply. Obviously the 500W power supply is NOT going to be putting out that sort of wattage. Instead it somewhat 'balances' what it can put out, depending on the demand. I don't know if any one spec can be continuously supported.

The rest of the information gets somewhat convoluted. The poster mentions a maximum of 408W for the two 12V rails combined, giving a maximum of 34A. This is below the 470's 38A, but the video card actually only uses 18A max according to another poster. So that leaves approximately 20A for the CPU, fans, hard drives and optical drives (this is at 'maximum' amperage - a condition you wouldn't want to push continuously). The CPU would be the other major user of the 12V rail with the other 12V rail users having fairly minor requirements (less than 2A each, on average).

CMSF is not going to intensively use the shaders on a GPU, but it can still push a lot of bandwidth simply due to the number of textures it handles (which would still pull some electrical current). How that translates into GPU load, I'm not sure. I guess you could try it out and see how it works. It's possible that between the CPU and the 470 your power supply may "crap out", typically resulting in the system suddenly shutting down (or "shooting sparks", though that should be somewhat rare with a quality power supply).

I believe the power supply should work with your video card and CMSF. However depending on the demands placed by the rest of the system you may want to eventually opt for a PSU with a bit more amperage on the 12V rail in the future.