Here's an example of changes between one minor update to another, taken from Nvidia's BIOS release notes. Most changes are hardware related, but some performance gain can be noticeable between revisions (mainly depends on your setup). The most noticeable gains can be achieved when updating to a major revision level from a major level.
3.15.01.00.00
Correct problem of Philips TV encoders not outputting color on TV
display.
Remove extra TV-disable sequence when disabling PAL TV.
Fix 32-bit Protected Mode Interface to BIOS (VBE/Core 3.0, i.PM Entry PointlE).
Fix the flickering in the double buffering VBETEST by moving wait for v- sync after the display address had been written, not before. VBETEST application would start drawing over the frame that was still visible, but now makes sure the frame address had changed.
3.15.00.13.00
Add code to correct issue initializing Infineon memory on certain OEM boards.
Update TV-detection code to set or clear scratch bits to indicate that TV is available (or not).
Change detect-display-device code to not turn off the TV if it is present.
Fix Chrontel NTSC modes 102, 103, 10e, 10f, 130, 131, 132, 133, 114, 115, 134, 135, and 136, which were incorrectly programmed.
Add NV11 desktop and mobile horizontal displacement changes for NTSC and PAL.
Chrontel: set register 1B[4:4]=1 to work around h-sync setup and hold- time bug by inverting P-OUT polarity.
Add pusha and popa to OEMFixupSetmode(). Fixes boot problem on 840 systems.
Remove check for the virtualize-encoder flag in OEMDetectTV(). This allows TV detection to work even if the virtualize encoder bit is set.
Avoid unslaving the CRTC when disabling the TV if a panel is active; this prevents an issue with NV11 mobile dual-link LVDS bloom.
Consolidate dummy functions using labels to conserve space.
Add dummy function label for getting current head.
Add code to Int10 entry to unlock extensions on both heads (if available) on BIOS entry.
Force BIOS entry to use head A after unlock.
Add code to Int10 exit to lock extensions on both heads (if available) on BIOS exit.
Maintain whatever head the BIOS sets as active (if available) on exit from the BIOS (instead of forcing head A as before).
Move the check for the virtual encoder from isTV() to OEMDetectTV() and OEMEnableTV(). This fixes the issue in which the BIOS
reprogrammed the encoder in a DOS box.
