Do new video card drivers improve older cards?

Probably a stupid question but it's really gnawing at me. i'm getting the new drivers for my nvidia 580m, and all the release notes talk about are improvements to the 600 series. Do these new drivers do anything for older cards? or are they just bug fixes rather than performance improvements?

If they only say the improvements are to the 600 series, then that's all that they will improve. The release notes are usually fairly accurate and specific.

New drivers will help older video cards at lot of the time and its still worth updating them. If they only mention 600 series cards it probably means that they don't do much for you, but its still nice to have newer drivers if you get new games.

I remember Dead Island running at like 10 fps on low until I updated the drivers and it went to 60ish fps at Max on a GTX 460 SE (RIP).

Sometimes they update the UI for the graphics settings as well.

You could also get lucky and see something like 20% improvement across the board like the last Radeon drivers for the 7000 series.