HP unexpectedly leads the pack in performance thanks to its dual-core E-350 APU. It's interesting to note that Gateway edges out Toshiba, despite using the lower-clocked C-50. This suggests that the dual-core C-50 actually performs better than the single-core E-240, which would make sense in threaded workloads.
Notice that, even though the dm1z uses a 7200 RPM drive, it suffers from slower read/write speeds compared to the 5400 RPM drives in the C655D and NV51B08u.
WinRAR is a multi-threaded application that scales well based on processor performance. This result confirms what PCMark suggested. The dual-core C-50 still outperforms the single-core E-240, demonstrating that you can get more speed from a slower dual-core part, even in basic desktop productivity apps.