I am flat out of ideas here. I have 2 Alienware M15x’s with 460m’s. Both have the same bios. All of the parts are the same except the processor.
Alienware ‘A’ gets full computational performance. It has an Intel Core i7-620M.
Alienware ‘B’ gets 142Gflops. It has an Intel Core i7-740QM.
I take the i7-620M out of the working laptop and place it into the low performance laptop (‘B’). Alienware ‘B’ now gets full performance.
There is definitely something going on with these processors. The problem is 100% reproducible.
I have verified that the ACPI tables are not only close, they are exactly the same. If I boot the good performing Alienware with kernel parameter acpi=off, then it goes down to being 142Gflops.
I am going to crack soon if we can’t figure this out
Side by side comparison is here
Thanks in advance for whatever help you can give.