Lavaflow

If it's a Unity game, try forcing the Unity Web Player process (or whatever it is) to use the graphics card.

I've had this same problem for a while, and as far as I know it had nothing to do with a BIOS update. If I unplug my headphones and restart, it usually fixes itself, and if it doesn't, restarting again does.

Does anyone know difficult is it to replace the GPU on the r4s? I've seen the videos, but only from hardware companies, and I don't necessarily... trust those.

Keep in mind that sometimes the requirements are in the CPU, not GPU, expecially in games where the are a lot of moving things to keep track of. The GPU might be able to handle the particles or whatever, but if the game has the CPU inputting in a lot of stuff as well that may slow things down.

For some more content mods, I woud say JaySUS swords (adds a lot of new weapon designs for variety) Falskaar (is basically an expansion pack. No, seriously. It's even almost completely VO'd) and some amount of Immersion mods. I've got Immersive animals, patrols, armors, and weaponry (all in separate mods). I'm assuming you have the basics like SkyUI and the unofficial patches and the like.

I get the feeling that that particular fps reading might be a little bit software bugged. I don't tend to set limits, but if I do, i generally put it a little bit above my screen refresh rate, to allow from frame drops. Tearing's never been a problem for me.