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, and coming at a cost that would make even a banker weep, 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, and we’ve got our hands on a sample boasting the mid-range quad-core 1.73GHz i7-820QM.

The first processors to arrive will be quad-cores based on a 45nm process, with 32nm dual-core models following in early 2010. Intel has kept the quad-core line-up refreshingly simple too, with the 1.73GHz i7-820QM flanked on both sides by the 1.6GHz i7-720QM and the top of the range 2GHz i7-920XM. Unlike their Core 2 Quad predecessors, all four cores boast Hyper-Threading; a move that allows the processors to handle as many as eight separate threads at once.

A perfunctory look at the modest-looking clockspeeds is enough to leave the keen bystander a mite underwhelmed, but those figures don’t take any account of the ace resting up Core i7s 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 mode 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.

Performance

If you’re not bothered about the details and just want to know how fast it is, the answer is very, very fast. Take, for example, the fastest laptop we’ve ever seen: the Dell Precision M6400 Covet costs the same as a nice second-hand car (£4,100) and offers a Core 2 Quad QX9300 running at 2.53GHz, 8GB of DDR3 memory, a 7,200rpm hard disk and high-end Nvidia Quadro FX 3700M graphics.

That combination earned an overall score of 1.64 in our application-based benchmarks, so it was with some surprise that we saw our early i7 sample sidle up alongside with 1.59. It might not beat the Dell, but put it in perspective – the CPU is rated at just 1.73GHz, it has half the amount of RAM and a 32-bit OS installed (to the Covet’s 64-bit OS), an inexpensive 5,400rpm hard disk and a far more modest GT 240M Nvidia graphics chip. Whichever way you cut it, that’s an impressive achievement by the Core i7.

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 multi-threaded 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 reduces to 2.8GHz and the power consumption to 70W. Load either of the two remaining cores, and Turbo Boost keeps power consumption hovering 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.

(Click on graphs to enlarge)

And, if you’re expecting all this power to turn your notebook into a mobile fireball, you’ll be pleasantly surprised. Our test sample was a modestly-proportioned 16in laptop, and with just a single vent at its side the i7-820QM idled at about 37 degrees centigrade, only hitting 77 degrees once the CPU was working flat out. Compare that to the 2GHz Core 2 Quad Q9000 in the recently reviewed Asus G71GX gaming beast, which idles at 50 degrees and peaks at 75 degrees, and the Core i7’s efficiency shines through.

As you might imagine, this efficiency helps improve battery life drastically. We rarely see quad-core laptops last more than a couple of hours even while sitting idle, but this one defied our expectations by lasting for over three and half hours with a bog-standard 4,800mAh battery. Push it to its limits, however, and our heavy usage test drained the battery in a mere 46 minutes.

Don’t forget, though, if you have to work on battery you can always engage Vista’s Power Saver mode – a measure which disables Turbo Boost and drops the CPU down to just 1.2GHz. In this scenario, with all four cores at full load, power consumption drops from 72W to a much more battery-friendly 52W – if you need all the benefits of multi-core computing, but longevity is important, too, then it’s a measure that can raise heavy usage battery life to a far lengthier 1 hour and 15 minutes.

Conclusion

Think it through briefly, and Core i7’s move to the mobile market might not make too much sense – indeed, combine huge power draw with massive heat output and you’ve pretty much nailed the absolute worst combination for the slimline confines of a laptop chassis.

However, Core i7 is a better match than anyone might have imagined. Several of its key features even seem to make more sense in a laptop than they do in a desktop PC, with Turbo Boost in particular making the perfect mobile match.

Price may yet prove to be a stumbling block, especially for the quad-core models, but going by the reasonable cost of Intel’s desktop-based Lynnfield platform upon which the mobile i7 platform is based, 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.

Called the Intel Atom 330, it runs at the same 1.6GHz frequency as its single-core predecessors, with a 533MHz FSB. With two cores and support for Intel’s Hyper-Threading technology, it appears to the system as four cores (as shown right). Being a desktop part, it comes soldered to an improved mini-ITX motherboard, now with a single DDR2-667 slot, Gigabit Ethernet and six-channel audio to go with the usual array of inputs and outputs.

We used a 7,200rpm SATA hard disk and 1GB of DDR2 to get our test rig set up, slapping on a fresh XP SP3 install to best compare the Atom 330 to the existing netbooks that will make up its primary competition. After installing all the drivers and running Windows update we installed our benchmark suite and set it to work overnight.

Now, to set the scene, the single-core Atom N270s we’ve seen in pretty much every netbook worth a review have scored anything from 0.3 to 0.44 in our benchmarks – our current A List choice, the brand new Samsung NC10, holds that top score, and we’re pretty sure that’s due to the extra time Samsung has had to apply some clever optimisation. The Atom 330 won’t be running at its quickest just yet, but we still expect a score in excess of that, and our multitasking test should show the largest margin of improvement. As an added contrast, we’ll also compare a VIA C7-D system, which recently scored 0.36.

The Results

The overall results are a little lower than we expected. (Note, all results are relative to our baseline Pentium D system, which scored 1.0). Yes, the Atom 330 is quicker than its predecessor – no surprise there – but we expected it to be by more than 16%. The individual tests make for more interesting reading, though, and explain where the Atom really excels.

In our combination of Office 2003 tests it actually failed to match either the old Atom or the VIA – this is clearly the result that’s bringing the overall average down, but despite repeated retests it consistently occurred. We could put it down to the Samsung NC10’s tweaked internals, as if we look at the first few Atom N270 devices they were closer to the 0.4 mark, lower than the 330’s result. More likely, it’s just the fact that Office 2003 is not a particularly processor-intensive benchmark, and doesn’t make efficient use of multiple threads.

By contrast, our 2D graphics tests comprise a variety of tasks in CorelDRAW, Photoshop and 3ds Max – tests which are ideally suited to multiple cores and Hyper-Threading. The Atom 330 dutifully comes into its own on this test, beating the N270 by 41% and the VIA by a whopping 71%.

For encoding we use dbPowerAmp and Canopus ProCoder to encode a variety of audio and video files simultaneously – a particularly intensive task. As you can see, here the Atom 330 merely edged it, by 18% over the N720 and 39% over the VIA.

Finally, our multitasking test runs all of the previous tests at once, a test of brute strength which low-power netbooks are simply not designed for. The fact that the Atom 330 scored 0.62, compared to the 1.0 of our baseline Pentium D system, demonstrates just how close today’s tiny netbooks may soon be getting to what was considered immensely powerful – and ran hotter than molten lava – just a few years ago.

Conclusion

All in all it’s a broadly impressive start for the Atom 330, performing best in the most processor-intensive tasks as you would expect. But the real question – and one we can’t answer until the netbook parts appear – is how that second core will impact on battery life. The quoted TDP of the Atom 330 is 8W, twice that of the old N270. It’s all well and good boosting the productivity of your netbook, particular with regard to running more than one application at once, but if the Eee PC’s fantastic battery falls from seven hours to three or four as a result, the 330 might not quite make it to the must-have level of its single-core predecessor.

Will netbooks move even closer to laptops with this CPU? Or will manufacturers keep it reserved for dearer models or desktop systems only? Time will tell, and we’ll bring you the results as soon as we get hold of one.

Though the chip is principally aimed at mobile applications – Intel claims it’s the world’s smallest processor – here it forms part of a super-quiet, super-efficient desktop PC from Tranquil, housed in the firm’s impressive all-but silent fanless chassis.

In this instance, the processor is a 1.6GHz single-core part, as you can see from the screenshot above. And it certainly lives up to Tranquil’s green ambitions: our readings had it idling at 31W, while power draw peaked at 36W.

Elsewhere, the specifications are as we’d expect of a Tranquil machine: a low-powered laptop DVD writer is complemented by one of Western Digital’s Green Power hard disks – the 500GB WD5000AACS; there’s 2GB of RAM, which helps to keep Vista Home Premium running at a fair old nip; and graphics are Intel’s integrated GMA 950.

The price looks enticing as well: the whole lot comes in at around £400 exc VAT. Check out the full review here, where we reveal benchmark results and our verdict on Intel’s newest CPU.