The determining factor on MH/s?

[grue]

What's the most important factor that determines a card's hashing ability? From what i heard, it's based on the amount of shaders. is that correct? what about core clock?

[Dude65535]

shaders, clock speed and chip design are the determining factors

[Cryptoman]

On a related note, does anyone know how many integer operations are necessary to compute one hash?

[os008]

Interesting question. I made a quick calculation ...

5850 -> 300 MH/s -> 2.5 TFLOPs

2,500,000,000 / 300,000,000 = 8.33 OPs

I'd say 9 OPs. Someone here who has more expertise in this, please provide some feedback.

[Beremat]

Interesting question. I made a quick calculation ...

5850 -> 300 MH/s -> 2.5 TFLOPs

2,500,000,000 / 300,000,000 = 8.33 OPs

I'd say 9 OPs. Someone here who has more expertise in this, please provide some feedback.

4850 -> 75MH/s -> 1TFLOP

1,000,000,000 / 75,000,000 = 13.333

It's probably dependent on core architecture as well.

[Meni Rosenfeld]

FLOPs are floating point operations per second, so I don't think they're what we're supposed to look at.

[ArtForz]

off-by-3-orders-of-magnitude.
HD5xxx needs about 4150 integer operations per hash
HD4xxx and nvidia 2/4/5xx about 6350 integer operations.
for all current architectures integer ops/second = number of shader ALUs * clock.
so a 5870 at 1600 ALUs * 850MHz = 1360000M intops/second, / 4150 = ~ 327.7Mh/s
4870: 800 * 750M / 6350 = ~ 94.5 Mh/s
GTX580: 512 * 1544M / 6350 = ~ 124.5Mh/s
etc...
usually published FLOPS numbers are simply intops * 2 (one muladd counts as 2 operations).

[os008]

HD5xxx needs about 4150 integer operations per hash

Thank you for the explanation.

usually published FLOPS numbers are simply intops * 2 (one muladd counts as 2 operations).

Wouldn't that mean ATi is much superior to nVidia in FLOPs; contrary to the reality? Don't you mean FLOPs = INTOPs / 2 ?

[Garrett Burgwardt]

FLOPS are completely irrelevant, since the hashing algorithm uses fixed point calculations.

You could not be more wrong by looking at the FLOPS rating of a card.

[os008]

There is still a correlation between FLOPS and Integer operations.

That's what i would like to know; what's the equation to convert between them?

[ArtForz]

published FLOPS for GTX580: 1581.1G
512 ALUs * 1544 MHz shader clock * 2 (muladd factor) = 1581.056G
published FLOPS for HD5970: 4640G
3200 ALUs * 725MHz * 2 (muladd factor) = 4640G

hey, what a coincidence!

[gigabytecoin]

FLOPS are completely irrelevant, since the hashing algorithm uses fixed point calculations.

You could not be more wrong by looking at the FLOPS rating of a card.

Ok, so where are the FPOPS ratings?!

[os008]

hey, what a coincidence!

So to finish an integer operation, it needs TWO sub-operations? I would've thought floats were harder.

Ok, so where are the FPOPS ratings?!

http://pastebin.com/AvymGnMJ
http://en.wikipedia.org/wiki/Comparison_of_ATI_Graphics_Processing_Units#PCIe_.28HD_5xxx.29

[apofis]

Look here http://forum.boinc.ru/yaf_postst395_Spicok-vidieokart-dlia-kranchingha-v--MilkyWay-home.aspx

[grue]

thanks for all the input guys.