Serial ATA performance — continued
We used HD Tach 3.01's 8MB zone test.
With the exception of the write speed test, the chipsets' Serial ATA performance is pretty similar in HD Tach. The P965/ICH8R combo only scores that high in HD Tach's 8MB zone test, not in the longer variable zone test. That higher average is a little deceptive, too. Here's what HD Tach's output looks like with the P965 and ICH8R.
Write speeds are all over the map when they should be tracking smoothly like read speeds. According to Intel, the problem is specific to the Caviar RE2. However, we've observed similar performance from other command queuing-equipped drives on the ICH8R, suggesting that the problem may not be limited to the RE2, but instead related to the interaction of the ICH8R and HD Tach's 8MB zone test.
Unfortunately, our Caviar RE2 doesn't support 300MB/s Serial ATA transfer rates, so that's holding back performance in the burst speed test. The nForce4 SLI X16's SATA controller is still a little quicker than the rest of the pack, though.