Thanks James.
The Pro 3 is well ventilated. It's upright on a desk, not in any case, with only power, USB, and monitor cables (1080p HDMI monitor) coming out of it.
Oh BTW I should mention that when I'm using the HDMI monitor, I have the surface display OFF. So it should only be driving one screen.
Right now, whilst in Metro IE, the cores are running around 39C which is better than before.
I'm not sure how to turn off power management stuff? The Pro 3 gives only the "Balanced" option, and the only things really adjustable are sleep time and screen brightness. There's no control over CPU or GPU performance, nor any of the usual stuff.
I had previously tried enabling Hyper-V, which gives back most of the power options, including the "Power Saver" and "High Performance" profiles. I tried the High Performance profile and it made no difference whatsoever to the throttling. I disabled Hyper-V afterwards, since it disables connected standby.
Not sure what else I can do beyond taping an ice-pack to the back of the machine :-) (Probably not a good idea if it leaks)!!
WoW ran fairly well last night, I'd say a little better when I turned down a couple of graphical settings - most notably particle effects. Still throttled, but was better, certainly very playable. Weird graphical glitches when on the loading transition splash-screen, but not sure if that's because of the monitor. First time I've ever seen that. I had been getting out of memory warnings too - which is unsettling because this is the 8GB model. However, yesterday I got a similar out of memory warning while testing WoW on my Pro 2 (8GB model also). Might be related to the monitoring tools (realtemp, coretemp, GPU-Z)??