Originally posted by: LOUISSSSS
Originally posted by: Team42
VID is the manufacturers' specified "stock" Vcore. For the e4300, that is 1.3250v. Not sure what it is for the Q6600. Check out the Intel website for processor specs.
but why is it that different q6600's have diff VID's sometimes a pretty big difference
In the old days when an IDM binned their chips for clockspeed based on the shmoo plot (voltage versus clockspeed) the IDM would simply use a "one size fits all" voltage for a given product SKU.
This made things like TDP per SKU more managable in addition to cutting down on the tester time. But the tradeoff is it was on the high-end of the safe side, many chips simply did not need that "one size fits all" voltage to operate at the rated GHz, thus they ran hotter than necessary.
What Intel fid with VID and their 65nm Core architecture was throw in the extra test time necessary to determine the next best approximate voltage (something less than the maximum allowed) for the chip to function at its clockspeed.
This basically means each chips individual shmoo plot is determined and the chip is then told "you will operate at multiplier X and at stock voltage Y".
Thus some Q6600 have VIDs of 1.2500V whereas others have a VID of 1.3250V...meaning the chip with a VID of 1.2500V had a shmoo plot for which operating frequency of 2.4GHz was safely acheived with a mere 1.2500 Vcore while the other chip's shmoo plot indicated it required 1.3250V in order to reliably function at 2.4GHz.
By the way if a chip's shmoo plot indicates it needs >1.3250V to reliably operate at 2.4GHz then it won't be binned as a 2.4GHz chip...they will go down the shmoo plot to say 2.2GHz and see if it operates at that speed with an acceptable Vcore.
(more or less, the numbers here may differ from Intel's exact procedures, but the gist of the process is what I have described here)