How Intel Laptop Performance & Efficiency Evolved From Nehalem To Broadwell

For the power efficiency results done while running from battery power, unfortunately the MacBook Pro with Core i5 520M no longer has a working battery... Thus the only "old" laptop for the power metrics is the Lenovo ThinkPad with Core i7 720QM.

During x264 encoding, the Core i7 720QM laptop had an average power draw of 54 Watts with a peak of 62 Watts. As a reminder, the Core i7 720QM has a 45 Watt TDP. The Haswell Core i7 4558U has a 28 Watt TDP. The Broadwell Core i3 5010U has a 15 Watt TDP.

To no surprise, on a performance-per-Watt basis the ThinkPad with Nehalem processor was the worst of the bunch. The Broadwell laptops with Core i3 CPUs were delivering three times more performance-per-Watt.

While running the Tesseract game, the Lenovo ThinkPad with i7-720QM had an average power draw of 44 Watts.

On a performance-per-Watt basis, the Nehalem laptop was four times worse off than a modern Broadwell laptop.