Concerning subtitles: Unfortunately you can't use DirectVobSub with DXVA, because for DXVA hardware accel. to work, renderer and decoder need a direct connection in the DirectShow graph, whereas in a configuration with DirectVobSub, it would sit in between. Also, it is unsure if DXVA will work for custom H264 content (not blu-ray).
I'm always playing videos from my HDD, never over network. Also, it is unlikely that there is any bottleneck at all, because I rechecked the player status information and it says that 0 frames have been dropped. Maybe, I should have described the issue somehow different: It's more like a judder regularly taking place every 10 secs or so. The video will run smooth for this period of time, followed by a "hickup" kind of thing.
I'm positive it's a display timing/refresh rate/driver issue, now what I would like to know is if GeForce cards are any better at video playback concerning this. I am playing 23,976 fps film content with 60 hz on my TV, since my TV is able to correct this, so it runs 100% smooth. THere's a technical term for this method, I think it's "5:5 pulldown". (That's the case with my standalone bd-player).
Now, what I'd like to know is playback 100% smooth using 24hz mode (or 60 Hz with pulldown) with 23,976 fps content on ForceWare/GeForce?
If it really is somehow the IGP, wouldn't it be better to just buy a cheap discrete card instead of buying a whole new motherboard?
I need a spare MB anyways, so I'd use it in another PC for office work...