When the 90nm B0 stepping Smithfield and Prescott2M designs transitioned to the B1 stepping 65nm Presler and Cedar Mill somehow Enhanced Halt and EIST support were corrupted. This meant that the B1 stepping couldn't downclock to save power. Although this really didn't put them at a power disadvantage compared to the B0 stepping because of the superior 65nm process, they weren't all they could be.
The C1 stepping is produced on a refined 65nm process and has Enhanced Halt State and EIST support enabled again. This means that the power consumption of these new processors are definitively lower. In fact, they are now competitive with AMD offerings with the 3.73GHz C1 965EE consuming about the same amount of power as the FX60. The 3.2GHz 940D and 3.4GHz 950D have their TDP dropped from 130W to 95W and all Cedar Mills now have a TDP of 65W. EIST support has also been improved with the processors now capable of going down to 2.4GHz versus the 2.8GHz of the 90nm EIST processors which will mean lower power consumption at idle.
The official Product Change Notification for Presler is here:
http://developer.intel.com/design/pcn/Processors/D0106083.pdf
Should also decrease output of heat at idle.When the 90nm B0 stepping Smithfield and Prescott2M designs transitioned to the B1 stepping 65nm Presler and Cedar Mill somehow Enhanced Halt and EIST support were corrupted. This meant that the B1 stepping couldn't downclock to save power. Although this really didn't put them at a power disadvantage compared to the B0 stepping because of the superior 65nm process, they weren't all they could be.
The C1 stepping is produced on a refined 65nm process and has Enhanced Halt State and EIST support enabled again. This means that the power consumption of these new processors are definitively lower. In fact, they are now competitive with AMD offerings with the 3.73GHz C1 965EE consuming about the same amount of power as the FX60. The 3.2GHz 940D and 3.4GHz 950D have their TDP dropped from 130W to 95W and all Cedar Mills now have a TDP of 65W. EIST support has also been improved with the processors now capable of going down to 2.4GHz versus the 2.8GHz of the 90nm EIST processors which will mean lower power consumption at idle.
The official Product Change Notification for Presler is here:
http://developer.intel.com/design/pcn/Processors/D0106083.pdf
They aren't massive improvements, just little crap. You won't yield much higher overclocks.Thanks guys, now I felt that I am $%$% in the butt, I got the B1 stepping even though it only runs at 45C I am still pissed...