I'm looking for a P4 3.06 GHz cpu with 533 MHz fsb and hyper-threading. The two processors that I keep finding on ebay seem to only differ in their core stepping, C1 vs. D1 (SL6SM vs. SL6PG). Both are supposed to be hyperthreading enabled, but I can only find confirmation on the Intel sight about the C1 core. So what's the difference? Are they both Hyper-threading cpu's? Should there be a price difference?