[REMOVED]

[teresaejunior]

[REMOVED]

[eleuthria]

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:

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?

If the sellers are using kh/s, they're referring to litecoin mining.  Litecoin hash rates are much lower than Bitcoin hash rates.

Ignore capitalization in general, all sellers and most websites are quite careless with capitalization when it comes to KH/MH/GH/TH/PH.


K = 1,000 hashes/sec
M = 1,000,000 hashes/sec
G = 1,000,000,000 hashes/sec
T = 1,000,000,000,000 hashes/sec
P = 1,000,000,000,000,000 hashes/sec

[vpasic]

Yup, Mh/s referring to Sha-256  and Kh/s referring to scrypt mining.

[zimmah]

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:

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)

[DrYak]

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)

Note: Above numbers are for mining coins using SHA256 hashes (Bitcoin, PPC, Namecoin, etc.)

For coins using Scrypt hashes (Litecoins & co) the numbers are quite different:

• CPUs: kilohashes/s - between a few k/s up to a few dozens of k/s for the most high range CPUs. A hundred of kh/s possible on really big servers with lots of cores.
• GPUs: kilohashes/s, still - between a dozen kh/s for embed/laptop/small business desktop, all the way up to several hundreds of kh/s for high range gaming rigs with powerful card. Note though that Nvidia are notoriously bad at the kind of math (integer and logical bit operation) used in hashing, AMD are mutch better.
• ASIC: none in productions yet. Again, don't expect jumps in performance as huge as with SHA256 - Scrypt uses memory and on a Scrypt ASIC a lot of the space will be used by the embed memory and thus wasted/not used by the Samba cores. You will probably see first more success with general purpose many-core chips that have lots of small lightweight cores, each with its own memory buffer. (Like Parallella boards) before Scrypt ASICS.

Also note that other hashes exist (Yacoin and Quark use various variants of SHA-3, or SHA-3 candidates. They should operate somewhat in between. But I don't have numbers for CPU and GPU for them).

Also note that Primecoins and co operate on a completely different way (they search for chains of prime numbers of specific length, instead of hashes of specific difficulties).
CPU give you usually hundreds to thousande primes per second. GPU aren't really functionnal and stable yet.

[RealityTruth]

how many khs is 1 ths thanks

[os2sam]

how many khs is 1 ths thanks

Why dig up such an old post?

1K = 1,000
1M = 1,000,000
1G = 1,000,000,000
1T = 1,000,000,000,000

Reference
https://en.wikipedia.org/wiki/Terabyte