Over the past six months Intel has pushed the ultrabook name so hard that one almost feels like it has neglected normal laptops. We’ve seen thin and light models hit price points previously unheard of, and already seen the kind of designs that Ivy Bridge will usher in. But the launch of the first Ivy Bridge processors doesn’t mean that these ultrabooks have arrived.
Intel is only launching mainstream Core i7 mobile processors initially, with four new models in the standard lineup and one Extreme Edition, the i7-3920XM. We expect to see more of these CPUs flow out over coming months, with ultrabook-focused models still a month or two away.
Apart from the extreme edition, the new Core i7 CPUs are all designed with a 45W TDP, with four physical cores, hyperthreading support and the new HD Graphics 4000 GPU. They are targeted at the desktop replacement market and are designed to pack some serious performance.
The major difference between mobile and desktop Ivy Bridge is frequency. The base CPU speed is lower on the mobile CPUs, which helps keep power use in check. To compensate for this lower base speed the mobile CPUs have much more Turbo Boost headroom – the desktop 3770 has a base frequency of 3.5GHz and a Turbo speed of 3.9GHz, while the mobile i7-3720QM has a base of 2.6GHz and a max Turbo speed of 3.6GHz.
Both mobile and desktop versions have the same 650MHz base frequency for graphics, but the mobile version can bump up to 1250MHz, while the desktop one tops out at 1150MHz.
In practice the new mobile CPUs are just as quick and responsive as the desktop models. We’ve been testing out one of the 45W Core i7 models, the 3720QM for a few days, and have been pretty astonished by how well it performs.
Our benchmarking has been done using Intel’s reference platform, Asus’ new N56 laptop. This is a 15in model which packs 8GB of DDR3 and shows off some of the key advantages that Ivy Bridge and its accompanying chipset brings to the market, such as four USB 3 ports.
The sample came with a GeForce GTX 630M GPU, however we ensured that this was disabled for our testing, so we could see just what the HD 4000 processor graphics were capable of. This isn’t designed as a review of the N56, rather an evaluation of the CPU inside, which means our testing is focused squarely on the processor.
In our real world benchmarks we were stunned at the result. These tests are normalised around a desktop 2600K CPU, which was the fastest desktop processor in the Sandy Bridge lineup at launch. A Core i7-2600K with 4GB of DDR3 scores 1 in these tests, and the mobile Intel 2670QM used in Samsung’s $3000 Series 7 Gamer laptop scores 0.84 overall.
The new Core i7-3720QM managed to equal the desktop 2600K with a score of 1, showing just how much extra grunt is packed into the mobile version of Ivy Bridge.
Even more impressively, it did so while still managing to outperform the equivalent Sandy Bridge line-up in our battery life tests, lasting for 3 hours 35 minutes in light use and one hour 15 minutes under heavy load.
This is still well under half what we expect from ultrabooks, but quite respectable when one considers that this is one of the fastest offerings in Intel’s mobile line-up. You wouldn’t want to venture too far from mains power when running one of these chips, but it has us excited about the numbers we will see when the ultrabook version arrives.
We even liked the integrated graphics core, which was until Sandy Bridge Intel’s major mobile weakness. Slightly slower than its desktop equivalent, it still managed 46fps at low detail and 24fps at medium detail in our Crysis tests.
It isn’t going to sate the appetites of hardcore gamers (and to be fair, we expect 99% of laptops using this model of CPU to come with a Discreet GPU), but it does show the increasing competence of Intel’s processor graphics, and bodes well for what we’ll see on lesser models of processor.
Several years ago Intel shifted from cutting down desktop CPUs to designing for mobile (and then pumping the designs up for desktops). Ever since then it has continued to deliver steady gains in both performance and battery life. From what we have seen of the Core i7-3720QM this strategy shows no signs of faltering, and yet again Intel has pulled ahead of AMD in CPU performance, while making significant improvements in graphics performance.
In many ways it won’t be until we see the Core i5 and low voltage ultrabook models that we can make a true judgement on Ivy Bridge. But all the signs point to Intel continuing to pull ahead in mobile CPU performance, and deliver some truly excellent offerings throughout the range.
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Issue: 343 | October 2015