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Review: Intel Core i7 - everything that Core 2 should have been - performance numbers

by Tarinder Sandhu on 3 November 2008, 09:31 4.0

Tags: Core i7, Intel (NASDAQ:INTC), PC

Quick Link: HEXUS.net/qapz5

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Pricing, turbo boost and power-draw


Processors UK pricing, including VAT US pricing, excluding local taxes
Intel Core i7 965 EE £600?
Intel Core i7 940 £350?
Intel Core i7 920 £250?
Intel Core 2 Extreme QX9770 £845
Intel Core 2 Extreme QX6800 £575*
Intel Core 2 Quad Q9450 £210
AMD Phenom X4 9950 BE £125

* phased out.

Looking at the table, the cheapest retail-boxed Core i7 processor will be the '920, costing somewhere in the region of £250 at launch. Bear in mind that it's around 20 per cent dearer than an equivalent Core 2 Quad (Q9450) but twice the price of the AMD Phenom X4 9950 BE.

Indeed, such is AMD's structure that its top-end quad-core CPU is in a value league of its own. Again, this needs to be taken into consideration when looking at the upcoming results.

The cost of Core i7 is prohibitive in comparison, of course, but ties in well with what Intel has been charging for its premium quad-core processors of late. You will pay exponentially more for clock-speed increases and, knowing this, the 2.66GHz Core i7 920 seems a safe bet at £250 or so.

Please note that Intel's Turbo Boost function was disabled for all tests.

Turbo Boost

In our architecture look we alluded to the fact that Core i7s have a Turbo Boost feature that increases clock-speeds in relation to workload and overall TDP. Should the workload require only a single core to execute the code the CPU's power circuitry can be set to overclock the processor to a 'safe' margin, and the final overclock depends upon how many cores are tasked and how hard they are pushed.

The engineering-sample Core i7 920 purred along at 2.93GHz when Turbo Boost was activated but the processor idle, and 2.8GHz when running benchmarks with any number of cores. That's one speed grade for free, transparent to the user if the chipset's BIOS option is activated.

The Core i7 965 Extreme Edition has a slew of options that allow the user to control the multiplier for each core - something the 920 and 940 don't.


Processors Idle power Load power
Intel Core i7 965 EE 140W
Intel Core i7 920 130W
Intel Core 2 Extreme QX9770 134W
Intel Core 2 Extreme QX6800 139W
Intel Core 2 Quad Q9450 129W
AMD Phenom X4 9950 BE 127W

Put under load with four instances of Prime 95, we found that whilst the Core i7 is reckoned to have a 130W TDP, which is the same as the QX9770 and Phenom X4 9950 BE, actual platform usage was somewhat higher for the i965 EE, to the tune of 35W.

Bear in mind that this includes the chipset and engineering-sample CPUs, so we'll re-visit the power angle as further X58 boards come by the labs.

We're in the midst of running overclocking numbers and this review will be updated once they're complete.