GPU power calculation?

[David Melik]

On classic POSIX-based operating systems (OS, like NetBSD Unix, or
additionally FreeBSD & OpenBSD, and preferably also Slackware GNU/Linux,
i.e., the oldest still-developed GNU/Linux,) what's a program/command
like bogomips for GPUs? Before anyone says, I do *not* mean benchmarks
(might try later, or maybe GPUs will be in nbench, which I usually only
run when getting/building a new PC)... what I mean is a command that only
does an instant calculation (for total GFLops/etc., even if parallel)
from specifications (processor speed, bus speed, other memory speed,
whatever, per core, or all cores multiplied with that noted.) I don't
want to have to run an entire benchmark every time I want to look up my
GPU power, or always have to look at obscure documentation I don't know
yet how relates to other (compared to like one maybe used to know whether
some 386sx16 system was 16MHz on 16MHz bus so obviously about 16 MFlops,
despite 387sx16 of same bus speed could do floating-point math faster...
now more buses, more RAM with more built-in speed hacks; I barely know
how to calculate CPUs, let alone GPUs, which have even more advanced RAM
and more built-in speed hacks...) It should be instant, like bogomips,
and whatever I may have used years ago on NetBSD (which I'll switch back
to as soon as can run two screens with one i6770K's GPU, then dual-boot
Slackware and/or run it from Xen.) I know, bogomips & etc. isn't exact
in relation to some tasks, but it's close enough for what I currently
want to know (i.e., I don't really even care if NVidia, AMD/ATi, Intel,
whatever GPUs are different for same speed, just trying to get a vaguely
approximate idea about the GPU, maybe more in comparison to ones of
similar type... if some calculation command took into account more parts
of GPU technology than I know, and specified certain tasks, that's fine,
I just don't want it using the GPU at that time, other than console/
terminal output stating basic numbers/details.)