Intel Core i7-975 XE Review - D0 Processor Stepping in Action
@ 2009/04/22It is evident that it doesn’t make sense from the performance prospective to compare the CPUs with new and old processor stepping. Since Intel didn’t introduce any new technologies and didn’t make any architectural changes, CPUs with C0 and D0 processor steppings working at the same clock speeds will perform equally fast in regular benchmarks. That is why it is not very interesting to dwell on performance of the new Core i7-975 XE in our today’s article. However, the heat dissipation and power consumption measurements are, on the contrary, extremely interesting to perform. This is what we are going to do next.
XS is full of reports of people OCing D0 steppings on air as far as their C0s on water, some report their D0 overclocks on water better than their own C0 chips did on DICE(!). It makes the B3 -> G0 Q6600 stepping change look like nothing.
Anandtech's first and (previously) only retail D0 Core i7 920 overclocked as good as their best C0 965 & 920 chips and did so using lower voltages on everything. To quote them:
First off, none of the C0 steppings we have would operate at these particular voltage settings, in fact two of them failed to POST. Our best C0 sample is requiring 1.425V on Core Vid, 1.250V IOH, 1.475V VTT, and 1.71V VDimm to just make it into Vista Ultimate 64 and we still have not dialed in application stability yet.