Just about 1 year ago, I built a desktop based on:\n\nIntel i5-650\nAsus P7H55D-M EVO\nG.SKILL Ripjaws Series 4GB 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model\nF3-12800CL9D-4GBRL\n<etc>\n\nThe Ripjaws mem tested OK with memtest86+. The system has been doing well for the last\nyear.\n\nNewegg now has a sale on:\n\nG.SKILL Ripjaws Series 4GB 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model\nF3-12800CL9S-4GBRL\n\nfor . Note that the "old" is 9D, the "new" is 9S.\n\nI can't discern any difference in the specs:\n\n"old" - [URL]http://www.gskill.com/products.php?index=222[/URL]\n"new" -\n[URL]http://www.newegg.com/Product/Product.aspx?Item=N82E16820231313&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&AID=10446076&PID=361116&SID=FW9wkedl[/URL]\n(apologies for wrap)\n\nThe Asus P7H55D-M EVO has 2 empty dimm slots. Any reason -not- to expect full\ncompatibility between the old and new Ripjaws mem?\n\nThx,\nP\n\n"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."