Question about amperage required for a GPU

[tomacco06]

I have a PSU (460W) with 3 12V rails, and the one with the highest amperage supported supports up to 18A. I am looking to replace my old GPU (Radeon HD 6450) with a GTX 750 Ti, and I've read that the recommended amperage is 20A. Will my PSU support it or will I have to change it?

 

[Gam3r01]

What is the units combined wattage for the 12V rail?

 

[tomacco06]

385W

 

[RedJaron]

The 750 Ti doesn't require additional PCIe power cables. It draws all its power from the mboard. If you have three 12V rails, then most likely the PSU has one 12V rail for the mboard's main 24-pin power, one for the CPU power cable into the mboard, and one for drives and peripherals. You should be just fine.

 

[Gam3r01]

You should have enough wattage, but I would recommend picking up a 750Ti that does not require an external connection.
PCPartPicker part list / Price breakdown by merchant

Video Card: EVGA GeForce GTX 750 Ti 2GB Video Card ($104.00 @ NCIX US)
Total: $104.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-09-27 16:30 EDT-0400

 

[Gam3r01]

The 750 Ti doesn't require additional PCIe power cables. It draws all its power from the mboard. If you have three 12V rails, then most likely the PSU has one 12V rail for the mboard's main 24-pin power, one for the CPU power cable into the mboard, and one for drives and peripherals. You should be just fine.

Certain high end 750Ti models do actually carry an auxiliary cable.

 

[tomacco06]

Thanks for the answers! They were very helpful.

 

[RedJaron]

Certain high end 750Ti models do actually carry an auxiliary cable.

Yes, they do, but they are a tiny minority compared to all the 750 Ti models out there.

 

[Gam3r01]

Some people still do make the mistake however, so it is worth pointing out.