Performance
We've cooked up this quick suite of lightweight applications in the hopes of testing some relatively typical uses for laptops like these. The first two tests are FutureMark's Peacekeeper, a web browser benchmark that uses JavaScript, and GUIMark, which measures Flash performance. Because both the Peacekeeper benchmark and the Firefox Javascript engine have changed during the past few months, we've only included a few scores for this first test.

Although the Eee PC 1000H caps its performance when on battery power by default, the 751 and LT3103 do not. In fact, the Athlon 64 processor in the LT3103 apparently lacks the lower multipliers needed to scale its clock speed dynamically below its 1.2GHz default. You can drop the 751 into a potentially lower power configuration using Windows' "Power saver" scheme, which will cap it CPU frequency at 50%, but the system is just too slow to be usable then. Given that the Atom Z520's TDP is so low, I fail to see the point. Instead, I tested the LT3103 and the Aspire One 751 only with the "Balanced" power scheme.

The Aspire One 751 scores under half what the Gateway does, giving us a taste of the performance gap between these two systems. Given its 1.2GHz Atom processor, the 751's placement between the full-speed 1.6GHz Atom in the Eee PC 1000H on wall power and that same processor's 800MHz-capped battery saver mode seems appropriate.

This result, frankly, is more what I'd expect to see from the 751, given my subjective impressions of its performance. Whenever you load up a web page with too much intensive Flash-based content on it, the 751 tends to choke. This last-place finish is a good indicator of the problem, but it's only the tip of the iceberg.

Next up is 7-Zip's built-in file compression and decompression benchmark. Decompressing a large file is one of those places where a slower CPU can leave you waiting for a few seconds, so we thought it would be a fitting application to test.

The 751's Atom Z520 manages to match the Gateway's Athlon 64 processor in 7-Zip, due in part to the fact that 7-Zip is multithreaded and gives the Atom's Hyper-Threading capability a workout.

Video playback
Our next set of tests focuses on the systems' ability to play back video in various formats. I did quite a bit of testing, so I've compiled the results in a table below that should be fairly easy to read. The CPU utilization numbers come from Task Manger and are approximate; I simply watched and recorded utilization percentages as the videos played.

The more notable columns are the ones that show how well the systems played each video format. I've broken the results into several tiers and color-coded them for easy digestion. Green means playback was acceptable, yellow is borderline, and red signifies notable problems. Note that "perfect" playback means complete fluidity, with zero apparent hitches. "Smooth" playback is still quite acceptable, with only the occasional dropped frame. As above, we used the "Balanced" power profile for all testing.

If you've seen us test QuickTime video before, you might be surprised by the results above with 480p QuickTime video, especially the low CPU utilization. Turns out that, in Windows 7, Windows Media Player can play QuickTime files, apparently with DXVA-based hardware acceleration. That gives the 751, whose chipset can accelerate H.264 decoding, an awful lot of help here. The 751 was obviously superior to the LT3103 with our 720p and 1080p test files, but that assistance wasn't sufficient to push it into the green.

In fact, both systems are pretty much a big pile of fail when it comes to anything beyond 480p QuickTime files. They handle the easy assignments competently—our standard-def DivX TV show and low-res Hulu in a window—but otherwise struggle.