We measured the time each CPU took to compress five high-resolution 48-bit uncompressed TIF images, each one with around 70 MB, to RAR format with the popular WinRAR application. The results below are given in seconds, so the lower the number the better.

Core i5-750 was 6.87% faster than Core 2 Extreme QX 9770, 27.29% faster than Core 2 Duo E8400 and 31.65% faster than Core 2 Quad Q6600. Core i7-920 was 14.81% faster than Core i5-750 (and both run at the same clock rate!), Core i7-870 was 20.53% faster than Core i5-750 and Core i7-965 was 23.94% faster than Core i5-750. Core i7-965 was 4.29% faster than Core i7-870 and Core i7-870 was 6.71% faster than Core i7-920.