by AlwaysLast » 06 Mar 2017, 13:25
Thanks once again to all for the advice.
In the end I spent a little more than I was intending to (just over £100) and got myself a 4GB AMD RX460 card. This is a fairly recent GCN card and will hopefully do me for a few years yet, past my next rebuild.
The short of it is that frame rate in STK is much improved, even when all or most of the graphics options are turned up to maximum(*), though there are still one or two minor glitches both with STK and with the computer in general.
The long story is that I ended up having to totally upgrade my OS in order to get the blasted thing to work. The card is newer than the kernel in the current stable OpenSuse that I was using (42.2) and newer than the version of AMDGPU in that OS too. I thought it would be a simple matter to move to a newer kernel, but ended up in a bit of a mess and moved to Tumbleweed instead, which has a much newer kernel out-of-the-box.
The biggest downside is that HDMI audio does not work at all with this card. I was never successful persuading STK to output sound over HDMI before, but I could happily play videos. Now, nothing. Apparenly I need either AMD's closed-source AMDGPU-PRO, or just to wait for things to get updated.
Regarding power use, another reason for getting this card rather than a slightly older one (I was looking at an R7 360 or 370) was the apparently similar performance for lower power use. It is rated to use something like 75W rather than the 100W+ of the older card. I have a power meter on the computer at the moment and as I'm typing this it's hovering around 60W (65VA). During complex STK play I've never yet seen it go above 130W, which I'd say is perfectly acceptable with my 350W PSU.
AB
(*)The classic example is the red-lit tunnels on Volcan Island. With my previous setup, even with relatively modest graphics settings, the frame rate would drop to perhaps as low as 12 or 15 going through the tunnels. With the new card, no noticeable drop at all.