Originally Posted by g3p0
A & B chips seem to come from Costa Rica, while C chips look Chinese.
They are all a little different.
'A' has a lower VID than 'B' and I have no idea about 'C' other than it comes from China
I posted that info on here about breaking down the numbers on the CPU. I took the A,B and C stepping info with a grain of salt because I can't find anything official from Intel about it. Now I'm convinced it's a bunch of crap. My chip has a "B" so I assumed it was a "B" stepping even though CPUZ reports it as being an "A". I just downloaded the latest version of Intels CPU ID utility and it also calls it an "A" so that throws the theory floating around the interwebs about it representing stepping or revisions. I think its just a batch/silicon wafer tracking number. Like A998, A999, B001 etc. if a plant outputs a higher yield in a specific period of time (week?) it may make it to "C". that would also explain why there are so few "C" chips.
What I know as fact about steppings and revision is this:
A major change is identified by a change like going from C0 to E0 (Stepping).
Smaller changes that don't warrant being called a stepping are called revisions ie A1, A2, A3, B1 etc. I'm not sure what the specifics are from going to A1 to A2 or A1 to B1 though. I'm sure it's burried someplace in Intel's data archives if somebody wants to look for it
Originally Posted by EckyX
Pretty much. "E" and "L" chips are likely binned to hit their clocks at lower voltages than "X" chips, but a 120w chip won't necessarily use 120w. It might use 85w but can't have a TDP of 80w so it gets bumped up to the 120w category.
It's actually more complicated than that. Don't confuse that Max TDP spec with that of something like a light bulb where it always draws that amount of wattage. Intel defined TDP: "Thermal Design Power (TDP) represents the near maximum power a product can draw for a thermally significant period while running commercially available software. For thermal solution requirements please consult the Datasheet, volume 1 (where available)." In very basic terms and not getting deep into the heat dissipation portion of this specification, this chip can (and will) draw more power if needed and satisfactory dissipate the heat generated. It would reason that this is because Intel has tested and determined that the CPU operating with a heavy load, with proper cooling will not exceed the maximum temperature allowed (TJ max). These X54xx CPU's are likely low leakage good performing chips. So this chip should run cooler than your typical normal wattage chip, at least under heavy load. An "L" series chip is probably a low leakage chip that doesn't meet Intel's requirements at higher frequencies but works well with lower voltage. My E5200 is a high leakage chip and even though it will match my X5460 in CPU overclock, @ 120 watt TDP it would burn a hole in my motherboard too. This is why these CPU's cost so much when new. Not because they can overclock as others have stated, Intel never approved of overclocking these Xeons. Somebody has to pay for the testing, binning and relative scarcity of these premium chips. Meeting this higher Intel standard doesn't guarantee a better clocking chip, but running cooler while under heavy load and drawing more power is a huge benefit. This is why they can make great overclockers.Edited by TerminalVoltage - 11/26/13 at 4:07pm