sjg1: .... ...my Motherboard (ASUS P4S533-MX) will support Pentium 4 with 512KB L2 cache, 533/400MHz system bus, Hyper threading technology up to 3.0 GHz.  .......This processor is the only FSB-compatible socket 478 still available on Dabs.com and it isn't HT. It won't actually be much of an upgrade from a whizz-for-quids ...