T420 i5-2520M swap to i7-2640M temp comparison

[Crumbs]

Temp comparison for 35 W CPU swap of a T420. I did the analysis of which CPU, debating jumping to 45W or coreboot. I did not see many before and after temp reports. I did this swap in the last few months and these results seem to be consistent with regular use. The fan is not running constantly and is likely running less than before.

Before:

• T420 ~ i5-2520M with ancient thermal paste
• current CPU temps around 50 idle, stress test to 96 C ~ 1-2 minutes

After:

• T420 ~ i7-2640M with cooler master cyrofuze thermal paste
• current CPU temps around 39 idle, stress test to 66 C ~ 2 minutes
• Peaked at 66, did not rise from 2-3 minutes, ie peak was 66. test run on battery may change on plug. Also bezel not installed, only keyboard
• run different day warmer in house, starting at higher temp near 50 C, in 3 minutes at 76 C, may have continued rising

How I ran the stress test in linux on the command line:

Code: Select all

for i in $(seq $(getconf _NPROCESSORS_ONLN)); do yes > /dev/null & done
top
killall yes

[dr_st]

Yep, ancient Thinkpad thermal paste (esp. in those generations) will give you these numbers.

[Crumbs]

Honestly what triggered the CPU swap was, if I'm going to spend the time to take it apart to replace the thermal paste I might as well upgrade.

I ran it longer, in 8-10 minutes it levels out at 82-84 C, drops back to 40 C in under 7 minutes after the jobs are killed.

[axur-delmeria]

If you're gonna flash Coreboot, use it as an opportunity to install Ivy Bridge CPUs.

[kapqa]

can do coreboot if the the T420 has also Nvidia chip?
mine T420 has already sandybridge quad, but ivy bridge would be tempting.