When it arrived on the desktop scene, Intel's Core i7 levelled the opposition. With enough power to embarrass Intel's own Core 2 architecture, not to mention AMD's efforts, Core i7 set the benchmark and set it high.
Now, with the new Clarksfield range of processors, it's set to repeat the trick in the laptop market. Thanks to Asus' G60J last issue, and the M60, we've had an extensive look at the mobile Core i7 processor.
The first surprise is that Intel's latest CPU doesn't come housed in a desk-swallowing behemoth. In fact, the Asus M60 is about as sleek and swish as you'd hope a desktop replacement would be, and it weighs just 3.34kg.
Inside, however, lurks one of the latest Core i7 quad-core CPUs. Asus opts for the mid-range 1.73GHz i7-820QM, a processor that sits in the middle of the range, flanked by the 1.6GHz i7-720QM and the top-of-the-pile 2GHz i7-920XM.
Unlike Intel's Core 2 Quad predecessors, all four of those cores boast Hyper-Threading, a move that allows the processors to handle up to eight separate threads simultaneously. And while those clockspeeds may sound a touch underwhelming, the figures don't take account of the ace resting up Core i7's sleeve - Turbo Boost.
Basically, if two or more cores are sitting unused and the processor isn't running too hot or drawing too much current, Turbo Boost kicks in and ups the speed of the remaining cores. For the i7-820QM, this can take the stock speed of 1.73GHz up to a maximum of 3.06GHz, while the i7-720QM and i7-920XM push up to 2.8GHz and 3.2GHz respectively.
It's very, very quick. Take the fastest non-i7 laptop we've seen: the Dell Precision M6400, which costs as much as a nice second-hand car and offers a Core 2 Quad QX9300 running at 2.53GHz, 8GB of DDR3 memory, a 7200rpm hard disk and high-end Nvidia Quadro FX 3700M graphics.
That laptop gained 1.64 in our benchmarks, so it was with some surprise that we saw the Asus M60 gain 1.59. It doesn't quite outstrip the Dell, but its CPU is rated at just 1.73GHz, it has half the RAM, a 32-bit OS (to the Covet's 64-bit OS), a 5400rpm hard disk, and far more modest Nvidia GT 240M graphics.
It's the Turbo Boost feature that really impresses, though. In our testing it worked without a hitch, dynamically overclocking cores to suit single and multithreaded applications, while disabling unused cores to keep power consumption within acceptable limits.
Attaching a power meter to the laptop shows the Turbo Boost function in action. Stress one core to 100% load and the clockspeed rises to 3.06GHz, while power consumption hovers around 58W. Fully load another core and the overclock falls to 2.8GHz, while the power consumption increases to 70W.
Load either of the two remaining cores, and Turbo Boost keeps power consumption around the 70W mark by lowering the overclock to a maximum of 2GHz. Finally, with all four cores flat out, it falls to a maximum of 1.73GHz with power consumption hitting peaks of 74W.
And if you're expecting all this power to turn your laptop into a mobile fireball, you'll be surprised. With a single vent at its side the i7-820QM idled at 37°C, hitting 77°C with the CPU working flat out. In comparison, the 2GHz Core 2 Quad Q9000 in the recently reviewed Asus G71Gx (web ID: 351529), idles at 50°C and peaks at 75°C.
This efficiency helps to improve battery life. We rarely see quad-core laptops last more than a couple of hours, but this one defied expectations, lasting 3hrs 32mins with a bog-standard 4800mAh battery.
When pushed to its limits, however, it lasted 46 minutes. But don't forget, you can always engage Windows' Power Saver mode: with all four cores at full load, power consumption falls to 52W and boosts heavy-usage battery life to 1hr 15mins.
Core i7 is, then, far more suited to laptops than anyone might have imagined. Price may yet prove to be a stumbling block, especially for the quad-core models, but we can keep our fingers crossed that the forthcoming dual-core CPUs will bring all the i7's benefits - Turbo Boost and Hyper-Threading included - to laptops of all prices, shapes and sizes.