MediaCoder

Running MediaCoder NT, to transcode an M2TS to ipad format

The encoding is going smoothly, about 45fps average, but my GPU usage is only showing up at about 8%

Why isn't it using all of my GPU?

GTX 480, 258.69 Drivers, Windows 7 Ultimate x64

You can try increasing the number of simultaneous tasks, though the bottleneck might be the decoding which is yet wholy depends on CPU.

Where do u see gpu usage?

You can use GPU-Z to monitor GPU usage (it's very tiny and much better than other apps that do this).