Quote from: teresaejunior on November 30, 2013, 05:15:32 AM

I was looking into buying a Radeon 7950 card, and while searching Google for its hash rate, I found some threads here on bitcointalk saying like 700 Mhash, ~660MH/sec, and at least 550MH.

Then I went to a few different sellers and they say the same card works on 650khs and 600Kh/s, using K, not M.

The only difference I could find is that M comes with a capital H, while K came with a lower h.

After some search I only found this on the Wiki:

Quote

Mhash/s = millions hashes per second (raw speed performance; may not be very energy efficient with some models).

I thought M meant Mega, as K would mean Kilo, now I am utterly confused... Could someone help?

M means mega, but mega is exactly a million.

The SI (system international) units are (there are more but these are the most commonly used):

Peta (P) = 1 000 000 000 000 000 (quadrillion)
Terra (T) = 1 000 000 000 000 (trillion)
Giga (G) = 1 000 000 000 (billion)
Mega (M) = 1 000 000 (million)
kilo (k) = 1 000 (thousand)
- () = 1 (one)
Centi (avoided when possible) (c) = 1/100 (1%)
milli (m) = 1 / 1 000 (one thousandth)
micro (μ) (u is informally used as well) = 1 / 1 000 000 (one millionth)
(in bitcoin we use satoshi here) = 10 / 1 000 000 000 (10 billionth)
nano (n) = 1 / 1 000 000 000 (one billionth)

CPUs usually measure in the kilohashes (thousands of hashes per second)
GPUs and FGPAs usually measure in the mega hashes (millions of hashes per second)
ASICS usually measure in GIGA hashes, Third generation ASICs measure in Terrahashes sometimes
The global hashrate is still measured in Terrahashes but should officially be measured in Peta hashes by now. They'll probably reach Exa hashes by next year. (1 Exa = 1 000 Peta)