Why are AMD GPUs faster than Nvidia GPUs (proof inside)

[rewertyn]

https://en.bitcoin.it/wiki/Why_a_GPU_mi ... than_a_CPU

AMD Radeon HD 6990: 3072 ALUs x 830 MHz = 2550 billion 32-bit instruction per second
Nvidia GTX 590: 1024 ALUs x 1214 MHz = 1243 billion 32-bit instruction per second
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And a Bitcoin "hash" is really sha256(sha256(x)). So when most devs here say 120MH/s it
really means 240 million SHA256 computations per second.

Each SHA256 hash covers 512 bits of data. So, as you guys have said:

To convert "Mbps" to "Bitcoin MH/s" divide by 1024.
To convert "Bitcoin MH/s" to "Mbps" multiply by 1024.
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1225 Mbps = 1,225,000,000 bit/s. 1 SHA256 hash is 512 bits.
1225 Mbps = 1,225,000,000 bit/s / 512 = 2,392,578 hashes/s.
1225 Mbps = 2.4 MH/s However bitcoin algorith requires 2 hashes not 1 hash per bitcoin hash. So that's 1.2 MH/s.

[phoebe]

Capitan Obvious is obvious.

[rewertyn]

w internecie trochę sprawdzałem o konwersji mhz do mbps przeważnie piszą że jest niemożliwe jednak znalazłem kilka ciekawych artykułów :

krokowo obliczona konwersja dla SATA "1.5Gb/s"
zaczyna się na stroni od : [6] SATA Drive Transfer Speeds, in Bytes (real, as opposed to fuzzy, math):
http://www.lyberty.com/encyc/articles/kb_kilobytes.html
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http://forum.onlineconversion.com/showthread.php?t=538
Been struggling for a while on converting bus speeds and transfers (per cycle I believe) into Mbps quantities e.g. I know that:
- an ISA bus of 16bits @ 8Mhz = 16Mbps
- an EISA bus of 32bits @ 8Mhz = 32Mbps
- a VESA bus of 32bits @ 25Mhz = 100Mbps
So my initial believe was a straight X bits * Y Mhz = Z Mbps, however the mathematics isn't that simple.

I do have a working formula of:
(X bits * Y Mhz) / 8
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http://www.accelware.com/Unit_Conversio ... nload.html
make easy conversion between more than 2,100 various units of measure in more than 70 categories
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http://web.forret.com/tools/bandwidth.a ... &unit=Kbps
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http://answers.yahoo.com/question/index ... 454AAOGVwn
PC Unit Conversions Mhz, Mbps, MBps, MT/s?
I think it goes like this but I'm not 100% sure:

1000Mhz = 1000Mbps = 2000Mt/s = 125MB/s. Or does megahertz not specify a data rate, only cycles?
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http://en.wikipedia.org/wiki/List_of_device_bandwidths
zaczyna się od: Random Access Memory
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1 MHz=1*10^6=1 000 000