I recently setup a HTPC for light gaming, it runs GTA at around 40fps, High settings at 720p (windowed for testing) - I know this card can do higher. The GPU usage is not surpassing 80% load and according to GPUz, it's consuming less than 10W of power, with it hitting voltage limits. This was my first GPU and I've never seen it do this before. The system has a very similar 500W PSU to how I used to use it - With an i3 3220. Temperatures are good too. Could the PCI-e have a smaller power output than usual? It's an Intel board I can't remember the model.
Edit: I set the core clock to the lowest it would go, the framrate is barely impacted but the usage is pinned at 100%.
Edit 2: The GPU now sits at A consistent 50-55% usage outside. Adjusting voltage power limits core/memory clocks all affect nothing except the usage when ajusting core.
- adjusting the res scale to 2.5 makes the GPU use 100%