Quote from: Gogluism on April 23, 2013, 12:28:30 AM

I have noticed a major decrease in hashing speed when I close my laptop lid, it goes down from 48M (Yes, I know it's low) to about 20M.
My power plan is always on high performance: hdd always on, no sleep/hibernate/anything else. Actually I always remove my battery when my laptop is on full throttle.
This only happens when my screen goes black, even when I close it for 3 seconds, I don't want to let it on for hours.
I use CGminer and GUIminer, same results.
AMD A8-4500M with Radeon HD 7640G, Win7/64, last drivers, everything is in order.
Any help is appretiated, thanks.

Probably GPU is entering low power state.
To find out if it does, launch GPU-Z and enable logging, after a while once the screen turns off check log for GPU frequencies and voltage, they should stay the same. If they are not the same - GPU enters power saving.
Not sure about integrated graphics, but discrete AMD GPU power saving can be disabled in Catalyst.
Also maybe CPU is entering extremely low power state, try checking with CPU-Z or ThrottleStop.
And since it is AMD APU, maybe it drops memory frequencies..
So.. you need to log all the frequncies and voltages Wink

btw, why do you remove battery? It makes no sense, except the heat maybe. And some laptops(Dell) think that they do not have enough power available when there is not battery and slow everything down.