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Review: Intel Core i7 975 Extreme Edition: piling on the pounds

by Tarinder Sandhu on 3 June 2009, 05:00 3.5

Tags: Core i7 920, Phenom II X4 940 Black Edition, Intel (NASDAQ:INTC), AMD (NYSE:AMD), PC

Quick Link: HEXUS.net/qasgu

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More of the same

Please head back to our in-depth architecture examination and performance numbers to see why Core i7 still has no desktop peer. It's big, efficient and, under load, screaming fast.

Is Core i7 975 Extreme Edition different from the rest, then? Cracking out the table.

Core i7 chip Cores
Architecture Process
Form factor Clock speed Uncore speed QPI speed L2 cache L3 cache HT Turbo Boost Memory interface
Etail price

Core i7 920 4
45nm LGA1,366 2.67GHz 2.13GHz 4.8GT/s 1MB 8MB Yes Yes Tri-channel, DDR3 130W C0/D0 £225
Core i7 940 4 Nehalem 45nm LGA1,366 2.93GHz 2.13GHz 4.8GT/s 1MB 8MB Yes Yes Tri-channel, DDR3 130W C0 £450
Core i7 965 Extreme Edition 4
Nehalem 45nm LGA1,366 3.20GHz 2.67GHz 6.4GT/s 1MB 8MB Yes Yes Tri-channel, DDR3 130W C0 £775
Core i7 975 Extreme Edition 4 Nehalem 45nm LGA1,366 3.33GHz 2.67GHz 6.4GT/s 1MB 8MB Yes Yes Tri-channel, DDR3 130W D0 £899

The same

Take a close look at the attributes and, in the main, the Core i7 975 EE is just a faster-clocked 965 EE. This time, the multiplier jumps 24x to 25x, and knowing that Core i7s run off a base clock (BCLK) of 133MHz, there's an extra 133MHz on tap. The Extreme Edition chips are unlocked anyway, so should you own a 965 EE then increasing the multiplier will give you a pseudo 975 EE.

Just like the other Core i7s, Turbo Boost technology increases core speed, usually by one multiplier, if the CPU's load is distributed over, say, two cores. Intel could clearly have released 975 EE at 3.46GHz, but why bother when there's no competition?


First brought in with the Core i7 920, the range-topping chip is based around the D0 stepping, whereas others ship with the original C0. There's no difference with respect to benchmark performance - a C0 and D0 Core i7 920 will perform the same - but the newer stepping purports to have better overclocking potential and may run at its stated frequency with a smidge less voltage. However, bear in mind that the TDP is still a hungry 130W.

Core i7 950

Intel will also introduce a Core i7 950, clocked in at 3.06GHz (23x 133MHz BCLK) that's identical to the Core i7 940 in every other way. It would be logical to assume that the new 975 EE and 950 will take the place of the 965 EE and now-defunct 940, moving the range up one multiplier but keeping pricing at roughly the same levels.


It's taken over six months for Intel to make changes to the Core i7 line-up. That's now happening with faster models replacing he incumbents, but they won't be cheap, coming in at £450 and £899 for the Core i7 950 and 975 EE, respectively.