jmke

Overclocking is very different on the Core i7. Unlike the Core 2 or Pentium D processors, the Core i7 CPU can monitor the current it draws as well as its power consumption—if it exceeds a certain level, the processor automatically reduces its clock speed. Intel calls this feature "Overspeed Protection." The limits hard-wired into the core are 100 A and 130 watts. Only the Extreme Edition allows the user to increase these values as they like, effectively circumventing the protection mechanism altogether.

Thermal power loss rises especially quickly when the core voltage is increased. Thus, it is entirely possible that a lower model Core i7 may offer excellent overclocking potential, but it will be constrained by the Overspeed Protection feature when its power dissipation triggers it. Obviously, Intel wants to prevent customers from buying an inexpensive processor and then overclocking it to very high or even extreme levels. Apparently, Intel has realized that the good overclocking potential of its processors has led ambitious users to choose less expensive models, relegating the faster (and more expensive) CPUs to the sidelines.

http://www.tomshardware.com/reviews/...em,2057-7.html

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jmke

Tom's Hardware's Chris Angelini -

"Intel has added an Overspeed Protection to its Core i7 processors, keeping them from exceeding 130W or 100A. The company says it’s a safeguard in environments where that much power or current could result in a problem. The workaround is a BIOS switch. Overclockers will want to disable it before trying their hand at faster frequencies."

"So, right at launch, you can expect most motherboard vendors (even Intel) to include an override of that Overspeed Protection function. On the DX58SO, it’s called CPU VR Current Limit Override. In ASUS’ Rampage II Extreme, it’s the CPU TM Function, which engages throttling based on TM2."

http://www.tomshardware.com/reviews/...i7%2C2063.html

Intel's Francois Piednoel -

"I am to be VERY VERY clear, there is not Overspeed Protection, we have a BIOS setting to bypass the PCU control of Current and Power. On smackover, it is call "CPU VR Current Limit Override", and it will allow you to bypass the thermal and courant limites on the Core i7 920 ans 940. Who ever claim the otherway around did not read the specifications enough hehehhe

we have recommanded to the motherboard makers to follow our steps.
So, relax, and don't worry ...

http://www.xtremesystems.org/forums/...&postcount=102

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jmke

interesting post @ XS from thread linked above

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npp

THG already posted an explanation for their strange results, they simply messed it all up. I wonder how they actually dared publishing all that BS without even making sure they switched the mentioned limit off in the BIOS... Pretty embarrassing, one more reason not to bother with their amateurish reviews.

jmke

they do bring forward a good tweak for us to check in the BIOS as apparently not all boards will allow to disable the check

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Kougar

Good to know about those settings. TR didn't mention them, but didn't seem to have any trouble or any need to modify voltages to get a 200MHz QPI bus http://techreport.com/articles.x/15816/9