VIA's KT333: The Athlon gets DDR333

What about Ultra ATA 133?

A new feature being introduced alongside the KT333 North Bridge is support for the Ultra ATA 133 standard through a new South Bridge. As the name implies, the Ultra ATA 133 spec gives ATA/IDE devices a maximum transfer limit of 133MB/s which is up from the 100MB/s of the previous Ultra ATA 100 spec.

While it's very clear that even the Ultra ATA 100 specification bought hard drives a huge amount of headroom to work with, there are some situations in which even the Ultra ATA 100 specification can be exceeded. When transferring data purely out of a drive's buffer it is possible for the transfer to occur at speeds greater than 100MB/s, but with the largest of buffers on IDE drives being 8MB we're not talking about an incredible amount of data here. Even then, the performance difference will hardly be noticeable since the vast majority of data will still be dependent on the time it takes to find and read/write data on the platter(s).

We've been playing around with benchmarks internally to see if we can ever create a situation in which we sustain transfer rates greater than 100MB/s thus requiring an Ultra ATA 133 compliant controller. Unfortunately the only situation we've been able to dream up is with a 4 drive RAID-0 array of Maxtor D740X drives where transfer rates just barely peaked above 100MB/s. Until single hard drives get that fast, Ultra ATA 133 won't buy you any additional performance.