Underclocking (and some limited undervolting) is controllable via software on most new GPUs.
That must be via GPU bios then.
Undervolting in video cards can be very challenging. It's hard to undervolt most cards in software at all. And only some can be undervolted(with some work) in bios. The only guaranteed way is through hardware mods. I've found most video cards are already clocked VERY close to their stability point, even undervolting .1v can require underclocking. My 7900 is stable at stock speeds, but a .1v undervolt causes instability unless I drop from 650 to 620.
Yes. Assumed as much. I probably opt for undervolting + underclocking. I rather buy a mid-end card. Seems like build quality is sometimes suffering on low-end cards. Then its only a matter how low you can go with undervolt+underclock. There must be some kind of limit.