Question RE: PCI Express 2.0 x16 and PCI E 3.0

[UNCDoug]

I was referred on a non-computer message board to you guys. Please pardon my ignorance--I've been away from building PC's for a while.

I have a mobo that has two PCI Express 2.0 x16 slots, and I'm running a GeForce 465 card currently on one. I'm not having any problems with it, but I'm in the mood to max out what my PC can do for a couple years before a new build. I've been out of the PC gaming scene for a while and wanna get back in.

Questions

1. Are PCI Express 3.0 cards compatible with 2.0 x16 slots? If so, how much power would I lose from the cards from it, if anything?

2. Would I be better off finding another card similar to the one I use now and running it in SLI mode as compared to getting a whole new card?

Thanks in advance.

 

[stahlhart]

I was referred on a non-computer message board to you guys. Please pardon my ignorance--I've been away from building PC's for a while.

I have a mobo that has two PCI Express 2.0 x16 slots, and I'm running a GeForce 465 card currently on one. I'm not having any problems with it, but I'm in the mood to max out what my PC can do for a couple years before a new build. I've been out of the PC gaming scene for a while and wanna get back in.

Questions

1. Are PCI Express 3.0 cards compatible with 2.0 x16 slots? If so, how much power would I lose from the cards from it, if anything?

2. Would I be better off finding another card similar to the one I use now and running it in SLI mode as compared to getting a whole new card?

Thanks in advance.

Welcome to the AnandTech forums.

PCI Express is backwards compatible, and you'll probably notice little, if any performance degradation running a 3.0 card in a 2.0 slot, particularly if you are talking about a 16X slot. If I remember correctly, some testing of this noted a small single-digit percentage difference in benchmark scores.

Given the age of your card, you would be much better off going with a faster single newer card rather than running a slower midrange card in SLI. SLI really ought to be reserved for situations where you have higher end (upper midrange or flagship) cards, in which running two of them will get you higher performance than a single current flagship card.

If you look into the VP ratings sticky above, you can roughly estimate SLI performance for a given card by multiplying its score by 1.5 -- in your case, it looks like a single GTX 660 or 760, or an AMD 7870 or 7950, would probably exceed the performance of adding a second 465, plus you'd gain the advantage of increased VRAM, which would help with newer games.

 

[UNCDoug]

That's exactly what I needed to know. Thank you so much!