I haven't been able to reproduce improved GPU performance by adding EVGA subsystem-vendor-id aor vendor-id to the EFI string or DSDT.
Sorry for the delay d00d just got home from work here is the info.plist you wanted from the AppleGraphicsPowerManagement.kext
Sorry I had to attach it as a .txt, it wouldn't let me put it up as a .plist If you need it in .plist feel free to pm me
You have AppleGraphicsPowerManagement.kext in /System/Library/Extensions/.
Do you also see it loading in System Profiler:Software:Extensions?
Booting in 32 or 64bit?
Would you attach the output of ioreg's display@0 and it's subtree sections?
That would include NVDA,Display-A@0 through NVKernel.
I've been unable to explain why removing this kext improves performance, when it shouldn't come into play with the GTX 285's device ID anyways.
So, if I read this right, the AppleGraphicsPowerManagement.kext has an entry to corresponding to nvidia deviceid 05e2, (a GTX280) but it looks as though your GTX285 has a device id of 05e3. so the kext would not try and modify its behaviour?