Overclocking and 3D
Finally, we ran tests in two areas that won’t necessarily be of interest with an Atom platform, but that will appeal to some of you – 3D and overclocking.
3DMark with the GMA
Since our motherboard had no PCI-Express or AGP slot (and since PCI graphics cards are getting scarce), we limited ourselves to the GMA 950. To compare it, we used the Gigabyte motherboard, equipped with the same chipset, with the Pentium E 2160 clocked to 1.6 GHz to match the Atom. So the two machines were using an identical IGP (GMA 950 @ 400 MHz) and a CPU at the same frequency (1.6 GHz). Both computers were fitted with a single DDR2-667 DIMM.
As you can see, with 3DMark 06, in 640 x 480 without filters, performance was weak... and above all, that the Pentium E remains noticeably faster than the Atom, even outside the world of synthetic benchmarks.
But remember, portable PCs that use Atom will use the i945GSE chipset, and the GMA 950 on this version is clocked only at 133 MHz.
Overclocking Atom
The Gigabyte Mini-ITX motherboard offers a few overclocking options: the FSB can be modified, between 100 and 700 MHz (sic). On our model, whose coefficient can’t be modified from the fixed 12, the base frequency is 133 MHz. We were able to reach a stable 1.8 GHz (12 x 150) without touching the voltage settings, and as much as 1.86 GHz (bus 153 MHz) by altering the FSB voltage in the board’s BIOS (+0.3 V for the bus). Performance increased in linear fashion, but so did power consumption – from 62 to 65 W between 1.6 and 1.8 GHz, and we measured 67 W for the platform with the Atom overclocked to 1.86 GHz. The difference can be explained by the increase in bus voltage. But note that the increase in power consumption isn’t due only to the CPU; the chipset was also overclocked.
Why no HD test?
Why didn’t we run tests on playing HD? Well, first of all because computers using an Atom processor aren’t intended for that. Intel is targeting NetTops, which are computers intended for Web browsing, not for watching Blu-ray disks. Also, we did try to play an HD DVD, just to see, but Power DVD wouldn’t launch without a modern graphics card capable of handling part of the decompression load. We would have tested some "HD" video, such as the trailers available on the Web, but several problems associated with doing that. The software player used influences the results, and the quality and complexity of these videos don’t match that of commercial video. Decompressing a DivX 720p stream at a few Mbit/s is one thing, but video in H.264 at 36 Mbits/s on a Blu-ray is something else.
