Poor performance with 7950, help?

[GoogalyMoogaly]

I recently did some upgrading first from a Phenom II 1055T (@ 3.8GHz) to a FX-8350 (4.2GHz) and finally to a i7 4770K (@ 4.3GHz).

Part of the reason I did the upgrade was I was worried about bottlenecking my HIS 7950 BOOST IceQ card.

I ran Heaven with both the AMD CPUs and got a score of around 720.
Now with my 4770K I get around 630-670.

The 4770K had a fresh install of Windows and since identifying the problem I've reinstall the motherboard drivers and un-installed and re-installed my graphics card drivers and gone from 13.4 to 13.10. None of this has made any difference to the score (which seems rather low to me). Well that's not entirely true, originally I was getting a score in the 400s, but the chipset driver re-install brought that up to the 600s.

If I overclock to 1150/1500 I get a score in the 800s, which also seems really low.

Any idea what might be causing my poor performance?

I should also say that using Afterburner I've increased the power limit to 20% and the GPU usage is about 99% during the Heaven run.

 

[GoogalyMoogaly]

Done a few driver re-installs and used the settings from Kaap's Heaven thread each time.

 

[GoogalyMoogaly]

I meant Heaven scores could varies between different version of drivers.

I got the same results with 2 different drivers though. Also the 13.4 ones that I started with were the same ones I ran with the other CPUs.

 

[GoogalyMoogaly]

Checked in GPU-z and it shows the card runs at PCI-e 3.0 16x when using 3D clocks.

Not got Tomb Raider.
Guild Wars 2 is giving poor performance too (it's what made me decide to run Heaven).

EDIT: Temp wise it only gets to the low 60s while running Heaven.