Don’t try this at home. I gave up on my HP Pavilion g4 laptop as is and decided to try reviving it with a new CPU. The price for the A8 part was down to $30 on ebay. In theory, I was hoping the new integrated GPU would be sufficient to drive gaming on an external monitor at 1080p. According to the source of all true knowledge, stepping from the A4-3300M to the A8-3500M should give a substantial boost to graphics performance.

transplant

There’s a G4 teardown video which basically demonstrates the process. Remove 900 screws, bang on the plastic seams, and it all falls apart. Some pics below as well. This part went smoothly for something you aren’t supposed to be doing. The CPU itself lives in a nice ZIF socket and pops in and out easily. Right about the time I removed the CPU I realized I hadn’t considered thermal paste, but I didn’t have any and plowed ahead. Hoping the paste remnants on the heatsink would be sufficient, I figured if not I wasn’t going to leave things in a million pieces, so applying thermal paste would be a second teardown no matter what. Everything back together and we turn it on.

old and new

It boots into Windows. Success! It’s running VGA resolution. Failure? Nope, just Windows deciding that it needs to install a new driver for whatever reason. Reboot a few more times, native resolution is back. Success! CPU-Z reports four cores. Temperatures seem stable. The Windows Experience Index doesn’t budge however.

Some observations on the old and new CPUs. According to wikipedia, both CPUs have a TDP of 35W. According to CPU-Z, the A4 was 26W and the A8 is 41W. The old CPU supposedly supported turbo beyond 1.9GHz, but I never observed that in practice. The A8 will briefly leap to 2.4GHz before settling in at 1.5GHz.

results

As stated, I was (over optimistically) hoping to double graphics performance. The g4 is only useful to me now as a potential gaming machine and would need to substantially beat the T430s I have. The Thinkpad already happily plays Skyrim at 900p, therefore the g4 needs to get things done at 1080p if it wants a spot at the table. I tested with the A4 first to have a basis for comparison. Hovered around 10-15 fps. With the A8 installed, I can now get 15-20 fps. That’s not double, only about 33-50%. To be fair, the shader count only increased 66%, but I don’t want fair, I want results. 20 fps isn’t really playable, and if I have to play at 900p, I’ll just stick with the existing T430s and it’s vastly faster SSD. Despite the lack of thermal paste, I didn’t observe any effects attributable to throttling and the temps remained reasonable during testing.

The patient survived the operation, but alas I set the bar higher than survival, so the g4 returns to the bonus bin.