Will a PCI Express x16 2.0 slot work with a PCI Express x16 3.0 graphic card

Question

I am thinking of getting a EVGA GeForce GTX 750 Ti and put it in my HP Pavilion a6518f Desktop PC. I upgraded the power supply to a 350W switch is enough I think. But I am worried about the motherboards PCI Express x16 2.0 slot, it appears the graphic says it used PCI Express x16 3.0. I am not sure if it will work can someone help.

My Computer with Specs.

The motherboard is a MCP61PM-HM (Nettle3)

Solution

PCI Express 3.0 is backward compatible with 2.0, the transfer speed is just lower. (http://en.wikipedia.org/wiki/PCI_Express#PCI_Express_3.x)

However, depending on the PSU quality (no-name entry-level or known-brand), a 350W PSU can deliver as low as 150W which will not be enough at full load. At peak load your computer can draw as much as 200W, including the new graphic card (the max power required should be lower than that, but let's say 17A on 12V). So just be sure your PSU can deliver at least 22A on 12V since a PSU is less efficient above 80% charge (and entry-level no-name PSU really don't like to be above this percentage). If you've a good-quality 19A on 12V that should be enough though, I'm counting large.

Comments

[Samin Y.]

excatly how do i know, were do i get the information. If the psu is not powerful enough, will the gpu simply not work or will i be casing harm to the card.

[piernov]

It depends on the PSU: either the PSU will shut down if it cannot deliver enough power (best case, which would not happen on bad-quality PSU), or it will just burn if the required power exceed its capacity for too long, or you will have a drop in voltage which will cause system instability (and if the graphic card isn't well designed too, it could be harmful for it but it shouldn't be the case). To be sure about your PSU, search for the brand on the web, you'll have some feedback, and check on the sticker on it if you have more than 19A on 12V.

[Samin Y.]

thanks so much for telling me, because i was not aware of this my cheap power supply only had +12V(1) - 17A and +12(2) - 16A

[piernov]

Two 12V with 17A and 16A should be fine. If the PSU design is correct, one would be used for CPU and other one for GPU, the 2 most consuming components. 150W is more than enough for your CPU (count 90W max.) and your GPU (count also 90W max.). Just check that the max. load is 200W on the whole 12V.