Now this is intressting, i just installed the other xeon x5675 in my htpc and i cant run my ripjaws at 1600 7-7-7-18 CR1 anymore, they perform even worse than the snipers at 1600 8-9-8-24 CR1 now and a stable boot is only possible at 1600 9-9-9-24 CR1.
At 1333 the ripjaws do a stable boot at 7-7-7-18 CR1 while the snipers can at 6-7-6-18 CR1.
At first i thought, it was because the formula would perform better at ram overclock than the gene, but now im sure its the cpu that causes the difference. It seems the xeon x5500 series performs better at ram overclock than the x5600 series does, might be thanks to a different memory controller architecture in the smaller 32nm die. On a side note the g.skill sniper seems to overclock better than the red ripjaws does and here i thought the ripjaws were the better ones at overclocking, but the sniper is ahead in terms of performance together with a westmere cpu. Overall the big increase in cpu performance, combined with lower voltage needs and lower temperatures thanks to the smaller die, makes up for the little loss in overclocked ram performance. Both xeon x5675 are running stable at 3,66ghz with 1,125v now, further undervolting might be possible.