I've been thinking about combining a few of my tools into a new program to give better thermal control over laptop / mobile CPUs.
I'm not yet sure what's possible but I did some testing tonight on a T7200 which uses a VID of 1.2750 at full load. When running a single instance of Prime95 Small FFTs, the core 0 temperature was up to 86C.
CPU-Z doesn't report the actual core voltage for this laptop, just VID, so actual core voltage was likely slightly less than that due to vdroop. I adjusted VID as low as it could go and I ended up at a VID setting of 1.0625 volts.
One thread of Prime95 was still running as I dropped VID lower and lower and lower and look at the results. In under 4 minutes, Core 0 had dropped 20C from its maximum of 86C down to 66C with this one simple tweak. I think most laptop users could appreciate a simple app that gave them this much control.
I didn't run a gazillion hours of P95 but it was obvious that this CPU is capable of running reliably at full speed without needing anywhere near the default voltage. You would save a lot of power and battery life when watching a movie or whatever without sacrificing any performance.
My plan would be to support Core 2 mobile CPUs including the 45nm series like the P8400. I like the possibilities but I need some positive feedback before deciding how much effort to put into this new project.
What do you think?
Bookmarks