FreeBSD is still missing the PAT feature
On freebsd lists John Baldwin (jhb@) told me: http://lists.freebsd.org/pipermail/f...er/057808.html
"It's not finished, no. The WIP is being done in the p4_pat branch (though it has some crud in it now that probably isn't needed). For more info about PAT and memory caching modes on x86 including MTRR's, etc. you can go download the vol 2 IA-32 arch PDF from developer.intel.com. It's not a conspiracy, there are no black helicopters."
Documentation can be downloaded from here:
System programming guide (253668) chapter 10.12 PAGE ATTRIBUTE TABLE (PAT)
John's code branch is here:
John Baldwin released a patch against CURRENT (still not ready to commit) here:
So.. the only way to get nvidia amd64 driver faster is to dig into the code and send patches to jhb at freebsd dot org