PCI Express performance
We used the same ntttcp test methods from our Ethernet tests to examine PCI Express throughput using a Marvell 88E8052-based PCI Express x1 Gigabit Ethernet card.
Throughput is consistent across each platform, but the CrossFire Xpress 3200 AM2 manages slightly lower CPU utilization than the rest of the field, followed by the nForce 590 SLI.
To test PCI performance, we used the same ntttcp test methods and a PCI VIA Velocity GigE NIC.
NVIDIA's nForce chipsets manage higher throughput here, with the Xpress 3200 trailing the nForce 590 SLI by roughly 70 Mbps. That's not much in the grand scheme of things, especially considering the nForce 590 SLI's higher CPU utilization. We were a little perplexed to see such high CPU utilization from the nForce4 SLI X16 chipset in this test, but performance was consistent across numerous test runs and even after re-imaging the test system.