I didn't see any specific numbers in reply to your comment, so I just want to point out that base clock Ghz for Intel and AMD is much higher for desktop CPUs than laptops. For your average click-read cycle, this feels better.

At full load, it depends on the heat dissipation; Dell's Precision 7XX0 dissipates heat well enough to keep the CPUs from throttling, but the 5XX0 does not.