In our case here at 2CPU.com, the power of two becomes the "power of four". Currently hyperthreading hasn't made it's way to the desktop Pentium IV processors (it's coming) and we haven't seen uniprocessor socket 603 boards to this point. I do know of at least one manufacturer who will be releasing a product like this shortly, and I will be testing it.Symmetric multi-threading (SMT) is going to become a hot topic when Intel unleashes the Hyper-Threading-enabled Pentium 4 3.06GHz processor on the unsuspecting desktop market, so it's probably a good idea to PYAITK before then. As the 2CPU article shows, Intel's current Pentium 4 Xeon processors actually run slower in some situations when Hyper-Threading is enabled, something that Intel has said won't be a problem with the Pentium 4 3.06GHz.
With Intel claiming that desktop Hyper-Threading products will not have the performance penalty we're seeing with current Xeon processors (even the latest 2.8GHz incarnations), I have to wonder if perhaps part of the problem stems from using SMP and SMT together. Then again, maybe it just took a little time for Intel to tweak Hyper-Threading to the point where it's never a hindrance. If the latter is the case, the changes should make their way to the Xeon line in short order.