Results: File Compression
We know from experience that 7-Zip is well-threaded, exploiting physical cores and benefiting from Hyper-Threading, too. The command performance from our Core i7s corresponds with our experience yet again.
In contrast, WinRAR's algorithms don't appear quite as well optimized. So, the Core i7s aren't set apart from the Core i5s we're using to compare in that workload.
The XPS One's Core i7 also appears to help in two of our WinZip tests, though the difference primarily reflects its slightly higher clock rate.