I am trying to decide between these 2 motherboards in which I plan to run a Celeron 300A overclocked to 450Mhz. PCXchange is offering this CPU, OEM or Retail, pretested by them on a BH6 mb and guaranteed to run at between 2.0 and 2.2V. They describe the Retail version as follows: Intel Celeron 300A w/128KB Cache Retail Box, 3-Year Factory Warranty, Heatsink/Fan Stepping SL2WM, 2.0v Mendocino Core, Multiplier Locked at 4.5X, Slot-1 Tested Retail 300A's are Stepping SL32A, Batch: 98421446, Pack Date 11/03/98. Why there would be 2 stepping numbers listed here is not immediately obvious to me since I do not understand what "stepping" means in this context. Can someone please help me out on this term? I am also thinking of buying a 128MB Micron PC100 8E Series 168 Pin DIMM CAS-Latency 2, 8ns, 16x64, Gold Leads from them. Is this the same as PC100-certified SPD SDRAM? And is Micron a good choice or is there another more preferable brand? I should also mention PCXhange's interesting offer of Celeron 300A's which have failed their 450Mhz burn-in tests but which run fine at 300Mhz (for only $55). They also offer untested 300A's (for $67)! I realize that I have been asking a lot of questions of the experts on this list and I am very thankful for the generous help I have already received. TIA Michael Eisenstadt PCBUILD maintains many useful files for download on our web site - visit our download page at: http://nospin.com/pc/files.html