PCI Express Scaling Analysis

PCI Express, Continued

The same applies to x1 PCI Express. We taped all connectors that were not required for the minimum link mode.

If you tape enough lanes, your PCI Express graphics card will run in x1 PCI Express mode only. This provides a bandwidth of 256 MB/s upstream and downstream.

Not every motherboard can be operated at low PCI Express link counts for PCIe graphics. In our initial article, we had to patch the BIOS of a DFI LANParty 925X-T2 motherboard to support the low-bandwidth connections. We also had to try several new motherboards before we found one that would allow us to run the benchmarks. We used a MSI 975X Platinum PowerUp Edition, but Gigabyte's 965P-DQ6 didn't work. We would have used an Asus Commando motherboard, but after upgrading the BIOS, we could not run graphics with low PCI Express link counts any more.

Shown above is a x16 PCI Express slot, as well as the contacts that have been taped to achieve a specific transfer mode. Click to enlarge.