For such a comparison to be relevant, you'd have to define the conditions very carefully. Windows and Linux are two completely different beasts, which means that where one excels, the other may be weak, and vice versa.
What this means is that even if you had a benchmark (like PCMark) that ran on both Windows and Linux and even if you had both operating systems on the same machines, you would see very different results that might be more reflective of compiler or coding differences than actual OS differences. |