Well, if you're basing your decision on only the processor I'd give the nod to the P75...barely.
but there are other things to consider:
RAM = same
HDD = same
Optical Disk = same
Sound = I don't care what kind of marketing hype they through out I've never seen a laptop that puts out good
sound and I don't even consider it in a purchase decision.
Display = same
Wireless = here's where the P75 starts to shine. It has a dual-band wi-fi adapter which means it can connect
to both 2.4 and 5 Ghz wireless networks and supports the latest and fastest wireless AC standard. The P875 is limited to 2.4Ghz networks and Wireless N.
Weight = I don't know if you'll be traveling with this but the P75 (including power adapter) will be an additional 3.2 ounces.
Ports = They both have 4 USB 3.0 ports and the same sound ports but the HDMI port in the P75 supports 4K video output.
Is that better? Only if it matters to you.
They're both good laptops.
The P75 has newer features but the decision boils down to your needs and budget.