Anyone successfully used a quad core i7 in a T420?

[bense]

I have a Lenovo T420 that I am interested in upgrading the CPU to a Quadcore i7.

I have tried this before with a i7-2820QM but it kept locking up, and it was not attributed to excessive heat. The only way that I was able to get it working was by disabling multi-core support and/or disabling hyper threading in the uEFI/BIOS.

Note: I am well aware of TDP, thermal design power, and I am well aware of the fact that Lenovo officially never offered this CPU for the T420. For the sake of this discussion, please assume that cooling is a complete non-issue.

I am also aware the Lenovo never officially supported a T9300 CPU in my R61e, nor did they ever support SATA II speeds, nor did they ever support any Mini-PCIe card that was not on their whitelist. Yet I have ran a T9300 in both my T61 and my R61e for over three years now with my middleton BIOS. I have spent a great deal of time searching for this before, but was unable to find anything.

Thank you.

[85101]

Which power adapter are you using? The lockup may be caused by insufficient power supplied. I installed i7-3632QM in my T430 and it requires at least the 90W adapter to run on AC power. 65W adapter will charge the battery only when the computer is asleep or off.