Would the 16x PCIe drop back to 8x after installing a second card on a P55 mobo for physics purposes?

[Kyanzes]

My question is simple.

Would the 16x PCIe drop back to 8x after installing a second card on a P55 mobo for physics purposes?

I'm still undecided between the 860/920 CPUs and the answer to this question could help me to reach a decision.

Thanks in advance!

 

[superunknown98]

Yes, I think it would have too. The socket 1156 i7's/i5's have 16 PCIe lanes on the chip so either the first slot has all 16 or 8. Unless the motherboard has a NF200 PCIE chip, which i have yet to see.

 

[Majic 7]

There are some boards with the 200 chip. EVGA 200 for one. There may be an issue with latency but haven't seen any benches yet, they haven't been out long enough. Just something I have seen mentioned.

 

[IlllI]

some might even drop down to x4 afterward http://forums.anandtech.com/me...=2333499&enterthread=y

 

[Kyanzes]

Even if the two cards were of different chipsets? E.g., a GTX280 and a 9800GT? No SLI.

 

[BushLin]

You've only got 16x PCIe lanes from the CPU and another six from the P55 via DMI so there's no way two cards can run at 16x. Bear in mind that the ondie controller is PCIe 2.0 so even at 8x/8x it'll be the same as PCIe 1.0 16x/16x.

 

[Kyanzes]

Okay. Thanks guys. I went 1366. The PCIe 16x compromise forced me not to choose the 8xx series.