Differences in performance between UL20A and Acer 1810T?

Hi,

Having tried the UL30vt, I decided to opt instead for a somewhat smaller laptop. Since I didn't know which one to get, my wife and I decided we'd try both the Asus UL20A-A1 and the Acer 1810T, and either each settle for the units we like or get an exchange in case we both want the same model.

There are certainly tradeoffs to each one. The UL20A has a bigger screen, charges a lot faster and vibrates less with an SSD in it than the 1810T does, the 1810T has a nicer, if smaller screen, has an HDMI port and a better sound dampening solution for mechanical hard drives (the UL20A was vibrating like mad with the original drive), and finally, and this I have had a very hard time accounting for: The 1810T seems to perform better than the UL20A despite using the exact same CPU, graphics chip and amount of memory.

The first thing I noticed is that the 1810T is a lot snappier doing simple stuff like opening new tabs in a web browser, typing into the address bar... not a big deal, but the 1810T definitely seems to feel a bit more responsive in general. This is all with an extra 2GB of Crucial RAM in the UL20A to match the 4GB in the 1810T. The biggest difference seemed to happen during video playback though. 720p video on youtube using the same version of firefox (specifically, I was using Lady Gaga's Telephone video to compare) was running smoothly on the 1810T, but would be a little choppy and occasionally hiccup on the UL20A. Configuring the Intel graphics adapter for better performance at the expense of power savings fixed the hiccups, but the video was still not quite as smooth.

I uninstalled every single unnecessary application from the UL20A, disabled unnecessary services using Black Viper's windows services guide, but neither that nor the SSD seemed to affect the responsiveness of the laptop or video playback. I finally found good evidence of the performance differences between the two units playing this silly collegehumor video with the task manager cpu monitor open. This is what it looks like on the UL20A one minute into the video:



This is what it looks like on the 1810T:



I know it looks like there's very little memory left in the UL20A screenshot because so much memory is used for caching, but I've run this test several times, even after immediately rebooting when there was plenty of "free" memory, and the situation remains the same no matter what.

The UL20A also seems to completely (if briefly) max out both cores doing various things like opening the browser application or navigating to new pages, whereas the 1810T seems to never completely max out doing those things. Power settings for the CPU are set the same for both: minimum CPU 5%, maximum CPU 100%.

Any idea what could be causing this performance difference?

Thanks much, Nir

Edit: I forgot to mention that I benchmarked both units with PassMark PeformanceTest and the UL20A got slightly better scores in pretty much every category including CPU and memory, which makes this all the more puzzling. IRQ conflict perhaps?