 Today I'll be using a synthetic benchmark in this case 3d mark 11 to evaluate something that I have received a lot of questions about Over the years so what you may or may not notice is that I have changed my test bench I have gone with an Intel x58 platform for this particular test. I'm using the gigabyte g1 gorilla motherboard Let's get you guys better look at that g1 gorilla motherboard with an Intel core i7 960 So that is a quad core processor. I've got that chip clocked at 4 gigahertz in order to reduce the any CPU bottlenecks that may occur in on my test and Now Okay, no do not always ask before opening this file So what I'm gonna be looking at today is the effect of PCI Express bandwidth on SLI performance so you can see I have not used the top slot And there's a very good reason for that if I populate the top slot Then it will run at 16x bandwidth and then if I populate the second slot I will have two cards running at 16x bandwidth if I populate these two slots. I will have two cards running At here we are PCIe 16 at 8x bandwidth So I'm just gonna switch to the other card and show you guys here. So there you are at 8x bandwidth. So that Is what we're gonna test I'm gonna see what the 3dmark score is running in these two slots versus these two slots So you guys can see how much of a difference there is in performance? Okay, so for my first run through we got x3 386 3386 3d marks in 3d mark 11 So now let's run them at 16x and see what kind of performance boost we get from giving them the full available bandwidth our two card configuration running the same test achieves 3389 3d mark so for comparison at 8x and 8x bandwidth we achieved 3386 3d marks So we oh, hold on. Hold on. No, no, we should put in the other one 3389 Okay divided by 3386 to find out the performance improvement 0.0001 Well rather that's a point 0.001% performance improvement by going from 60 8x 8x to 16x 16x PCIe 2.0 slots so To anyone who wants to run SLI or crossfire on the Intel p67 platform I guess this means you're pretty safe from performance degradation Even with high performance GPUs like the GTX 580 Thank you for checking out this little episode of Linus tech tips. Don't forget to subscribe for more unboxings reviews and other computer videos