Review Price £224.06
Looking first at the Core i7 870, it puts in a quite astonishing performance, consistently keeping tabs with the Core i7 965 and more often than not beating the Core i7 920. Admittedly, this isn't surprising considering its price but it's still good to see that this apparently mainstream/budget platform has the headroom to compete with the best. In fact, once you consider the power saving of this platform and if you don't plan to run crazy SLI setups it looks to be the clear choice over Core i7 900, though we'd obviously recommend you go for the much more sensibly priced Core i7 860.
Things aren't quite so immediately positive for the Core i5 750 with its lack of Hyper-Threading particularly telling in multi-threaded tests. However, once you consider that its default clock speed is only 2.66GHz, it's clear that Turbo Mode and the improvements inherent to Nehalem are working wonders as this £160 CPU has some of the best single-threaded performance figures in our tests. Most importantly, though, it betters anything at its price point. And again, once you consider its power saving enhancements it's a clear choice for a bargain CPU.
While many of us are happy just to let our CPUs run at their default clock speed (because overclocking often requires disabling power saving features and CPUs are generally 'fast enough' now anyway) it's always nice to get a bit of free performance where possible. That said, we always feel it's of limited benefit to spend hours tweaking the living daylights out of a CPU to get the best from it when the amount of overclocking headroom varies between samples of the same CPU. With this in mind, we set out to see what we could come up with just by adjusting the base clock and leaving the CPU to control the rest of its functions, i.e. we left on Turbo Mode, all the power saving features, etc. This resulted in an overclock you might actually use everyday without tripling your energy bill.
With its higher initial clock speed and use of Hyper-Threading the Core i7 870 doesn't have a lot of headroom for overclocking (without some exotic cooling) as it already generates a lot of heat when going full tilt. Nonetheless, we were able to get this CPU running at up to 3.92GHz in Turbo Mode. That equated to its Cinebench scores rising from 3804 to 4,096 in single-threaded mode and from 14,197 to 15,027 in multi-threaded mode - a percentage increase of eight per cent and six per cent respectively. While this wasn't a huge increase, with power consumption only going up from 170/255 to 175/265 (idle/load), it's a nice little overclock you could use everyday. Incidentally, trying to push things further caused power consumption and temperature to sky rocket so we wouldn't envisage getting much more out of this CPU.
Conversely, the Core i5 750 was one of the best overclocking CPUs we've ever encountered. Again without changing anything but the base clock (up to 150MHz) we were able to get this CPU running at 3.8GHz in Turbo Mode. This made its Cinebench scores rise from 3,412/11,294 to 4,154/13,496 (single/multi), an increase of 22 and 19 per cent respectively. Best of all, power consumption only went up to from 168/240 to 180/255 (idle/load). Quite simply, this CPU is a bargain hunting overclocker's dream!
Intel may have annoyed the computer buying public by releasing two whole new platforms within a year of each other (Intel does insist the two will coexist, by the way) but the simple fact of the matter is Lynnfield is a superb platform. Yes, for enthusiasts, Core i7 900 is still the platform of choice due to greater multi-graphics card support, triple channel memory, and the Core i7 920 being such a great overclocker. However, Core i7 800 provides much the same performance as Core i7 900 but costs less (at least Core i7 860 will) so unless you're seriously considering multiple high-end graphics cards we'd stick with Lynnfield. As for the Core i5 700, it's set to be the budget CPU of choice with great performance out the box, some really great overclocking potential, and superb power consumption figures. As expected, AMD has dropped its prices with the Phenom II X4 965 Black Edition now topping the range at just £155 but we have to say, if you're buying a new system, Core i5 is the way to go.
Core i7 870
Core i5 750