GTX 770 in Mac Pro 5,1 running at PCIE Gen 1

[Ron Harrison]

Hi, I currently have Windows 10 Pro 64 bit installed on my Mac Pro 5,1 (I'm not using bootcamp, Windows is the only OS on the machine) So, I decided to install my GTX 770 because I plan to make this my main computer. I then installed the latest driver and went to run a benchmark of a game. I noticed though that the performance was a bit lower than on my PC when using the same card. I think I remembered hearing something about GPUs that weren't flashed with a Mac compatible BIOS running at a lower PCIE speed so I went and got GPU Z. To my surprise it did indeed say it was running at a PCIE 16X Gen 1.1. Is this a normal thing? I don't imagine it is since I'm pretty sure that the Mac Pro motherboard has supported PCIE Gen 2.0 since the 2008 model. I couldn't find any info online so I thought I'd ask here.


Thank you

 

[h9826790]

Hi, I currently have Windows 10 Pro 64 bit installed on my Mac Pro 5,1 (I'm not using bootcamp, Windows is the only OS on the machine) So, I decided to install my GTX 770 because I plan to make this my main computer. I then installed the latest driver and went to run a benchmark of a game. I noticed though that the performance was a bit lower than on my PC when using the same card. I think I remembered hearing something about GPUs that weren't flashed with a Mac compatible BIOS running at a lower PCIE speed so I went and got GPU Z. To my surprise it did indeed say it was running at a PCIE 16X Gen 1.1. Is this a normal thing? I don't imagine it is since I'm pretty sure that the Mac Pro motherboard has supported PCIE Gen 2.0 since the 2008 model. I couldn't find any info online so I thought I'd ask here.


Thank you

Normal. Only flashed card can negotiate at PCIe 2.0 in Windows on cMP.

 

[Ron Harrison]

Normal. Only flashed card can negotiate at PCIe 2.0 in Windows on cMP.

Well that's surprising, I guess I'll do more testing to see how much of an impact it makes. If I'm not mistaken, PCIE 16x at Gen 1 speeds would be equivalent to PCIE 8x Gen 2 and Gen 3 4x?

Thanks for the quick and clear response!