Ok thanks everyone, some good food for thought, I'll try address everyones advice:
- It's two in (140/120 at ~9v) and two exhaust (both 120 at 7v). Positive pressure is achieved by having the front draw in more air than is exhausted.
- Agreed, top exhaust is probably not doing anything and at worst harmer CPU cooler airflow. Will try address that.
- I have RMd the card, but in case they send back one that also runs quite hot, I want to maximize the airflow in the case. It was when I was taking it out to send it away did I notice the front half was decently cold but the rear end of the GPU ws noticeably warmer (inside the case I mean, not the GPU itself, although that is where the core is so I'd expect it to be warmer, I'm just not sure it's getting air flow)
- HDD cage, def thought about removing it (it's riveted on) but it's currently hiding all the cable management, which I have nowhere else to place.
- Tidy up cables in front of bottom intake, I've tried, the only major cable interfering is the front USB3 and it's cables are so rigid I can't bend them further.
- Cutting hole in side panel, it's tempered glass so that won't work
- PSU intake, I think it's better drawing in fresh air in its own but maybe he'll being the other way.
- One thing I could try is using some standoffs to rise the side panel off , not enough to notice but enough to let some air escape, but I'm not sure if that would make it better or worse.