VGN-NR38E CPU runs at half its rated speed on battery

[av-115]

Hi all,

I've posted about this problem on Tom's Hardware but I've had no answers so thought I'd post here as well.

I upgraded the CPU to a C2D T9300 2.5GHz but on battery power the multiplier becomes locked to 6 (instead of 12.5 - 13.5) and CPU runs at 1.2GHz. This causes a slowdown and Youtube videos lag. I've checked this with CPU-Z & what ever load is placed on the CPU its frequency stays at 1.2GHz unless the charger is plugged in. I'm using the High Performance power plan in Windows 7.

The problem seems to be related to BD PROCHOT as when I un-check this in Throttlestop the issue goes away and CPU runs at 2.5GHz. However when I reboot the laptop, BD PROCHOT is enabled again and CPU is back to 1.2GHz.

Please can someone help?

Thanks

Andrew