Difference with PCI-Express x8 vs. x16?

[imported_ST]

Since my HTPC wasn't too happy with the spacing and the associated temperatures with my 7800GTX in the main (blue) x16 slot on my A8N-SLI Premium mobo, I decided to move it to the other black, x8 slot. This helped immensely with the airflow in my system now, so that the system isn't essentially segregated into 2 parts (CPU to the right of the 7800GTX, and the rest to the left). I ran a series of benchmarks, primarily 3DMark05 with this setup, switched back to the x16 slot and compared the results: completely IDENTICAL! I realize the resolution of 3DMark05 is 1024x768 (freeware version) so it won't need as much bandwidth. So does the present day high-end video card really necessitate x16 PCI-Express slots (my simplistic benchmarks say no), or will I actually see a difference when finally running at say 1920x1080?

 

[coomar]

no the 7800gtx doesn't fill up 8x bandwith