christian42 wrote:The question is:
Can I upgrade a E734/E744/E754 with a i7-4710qm/i7-4712qm-cpu (same power) if the motherboard have a HM86-chipset, or ist a motherboard with QM87-chipset absolutely necessary like in the data sheet.
I routinely do 3rd and 4th generation CPU upgrades on laptops from many manufacturers and always no problem, 4th generation I don't even check the chipset (however I recommend checking before disassembly). I have also tested the E754 physically, original i5-4300M vPro version, replaced with i7-4700MQ and i7-4702MQ, both run, 4710/4712 will work as well, just watch out for temperatures (45W version), I eventually solve these by undervolting CPU (about -50-100mV) the 4700MQ version.
Manufacturers give the same boards for the whole model range, they just change components like CPU, LTE module, RAM etc, everything else (even cooling circuits) are usually the same.
I recommend updating the bios before upgrading.