Radeon 6490m gpu clock fault

Recently I've had a lot of problems with the Radeon 6490m 1Gb edition in my DV6-6156ea.
The clocks got stuck at 100Mhz core and 41Mhz memory; should be 750Mhz & 775Mhz respectively.
It's 4 months since it first happened with a driver update direct from AMD.
And Ive just fixed it, but I'm not totally sure as GPU-Z says the memory clock is at 250Mhz while Afterburner says 775Mhz.

The solution for anyone wondering was to roll back drivers to HP sp55092, switch power-play on in CCC and then use an overclock to kick the gpu back to its standard clock rates.

TL;DR Which gpu monitoring program is more likely to be correct? GPU-Z or Afterburner?

 

Idk if it's a wrong way of counting but my memory clock speed's also seemed to be wrongly measured by GPU-Z. The Core clock's fine. I also experience no performance degradation. GPU-Z should be wrong on this.

Idk if I read you wrongly.

• Catalyst 12.4 WHQL ('12 Apr)
• Catalyst 12.6 WHQL ('12 Jun)
• Catalyst 12.8 (Switchable graphics mode aka fixed was broken on this update across various vendors, BSOD during startup for many systems - AMD Issue) ('12 Aug)
• Catalyst 12.10 (Switchable BSOD fixed) ('12 Oct)
• Catalyst 12.11 Enduro WHQL (Meant for 6000-7000M GPUs only) ('12 Nov)

There were so many reference driver updates. I had them all. If you're talking about HP modified drivers, probably it'll be more than 4 months since a driver was released. OEMs do that too often.