Laptop CPU stuck at slow speed

[Vertigo]

Got a weird issue with a Sony Vaio laptop here.

It has an i7 mobile CPU. If the laptop is run on mains power then all is fine but, if on battery, then it's incredibly slow. Checking with CPU-Z shows that, in this case, the CPU is clocked down to around 800Mhz and stays there no matter what the load.

It's running W7 Pro and the power settings are set to high performance. I've even tried setting the minimum CPU performance levels to 100% but this has no effect.

Does anyone have any ideas what's going on or how I can fix it. The laptop is basically unusable when on battery.

 

[d_brennen]

BIOS setting perhaps? I know Sonys of a couple of years ago had some god-awful power management software, perhaps this is conflicting with Windows' power schemes

 

[Orcvader]

BIOS setting perhaps? I know Sonys of a couple of years ago had some god-awful power management software, perhaps this is conflicting with Windows' power schemes

Might be this. Also see if there's any Sony software that controls the power management as well (maybe even uninstalling them), I don't see the point in all that bloatware so usually just do a fresh install of my own...

 

[smelly_legend]

Maybe give throttlestop a try?

 

[unclewebb]

ThrottleStop 5.00
http://www.techinferno.com/downloads/

I don't recommend that you use ThrottleStop while on battery power but when a manufacturer drops your core speed down to 800 MHz, I guess you have to do something.

Keep away from doing any extreme testing like Prime 95 or Linpack when on battery power and you will probably be OK. Manufacturers build these limitations into their laptops to try and prevent the battery from being damaged or catching on fire. It would be nice if they were more upfront about what speed their laptops will run at when on battery power but there is lots of dishonesty in the market place.

 

[Admetos]

To the OP.

Open power saving in Windows 7, and check max % CPU usage when under battery power.

 

[Ch3m1c4L]

On an old dell my parents had there were bios settings, which were weird.
I set the power management features which would throttle the cpu down, to off. I then forgot i did this, 2 years later I give the laptop to my girlfriend, It was super super super slow, at 200mhz. It took me AGES to think about turning it back on, so that it would stop clocking it down....

 

[Dom86]

As JasonM said check the power settings and have cpu at 100%, but I did have this problem pnce with my i7 in my laptop I tried everything and the only thing that worked for me was a clean install of windows, i know it's not a great solution but it worked.