With the command line you posted at 480p, you ain't going to max out x264.
As for your encoding speed. With a 9800gt, you're going to get about 30-40fps give or take decoding speed with 1080i.
Of course, x264 can encode faster than that, but it isn't magic, it can't encode faster than the decoder is delivering frames to it.
And as you're obviously de-interlacing, that will slow down the decode even more.
for the x264 settings which is the same as the DXVA SD profile without mbtree
No way. DXVA will handle alot more than that.
2 1/2 options,
For 1 pass CRF encoding,
--preset veryslow --level 3.1 --ref 10 --vbv-bufsize 14000 --vbv-maxrate 17500
Or for 2 pass bitrate encoding, encode to a lossless file first and then use whatever commandline you want.
Yes, you will end up doing 3 passes. 1 lossless, 2 x264. But the 2 x264 passes will be very quick when encoding from a lossless file.
The 1/2 option is to run a quick CRF check with the command line I posted and see what your CPU usage is. If you're CPU usage is high, and/or you have a slower encoding speed than you did previous with your command line, and you want to do 2 pass encoding, than you can skip the lossless encode first, as you are obviously maxing x264 out.
Oh, probably the biggest thing also, is that if you are doing a 2 pass encode, the first pass of x264 will automatically do a "fast first pass", which means it lowers alot of the options within itself to increase encoding speed. This WILL result in minimal CPU usage. Remember, even though it lowers options to increase encoding speed, it can't encode faster than the decoder is delivering frames.
edit: What I posted is way off topic for this forum. As admin pointed out, you're best served by seeking help related to x264 in the doom9 forum x264 section.
And as for an older driver increasing encoding speed. There would appear to be a problem with the latest nvidia drivers and your hardware setup. You should take that up with Nvidia.
