On 13/12/2013 00:52, David Brown wrote:

On 12/12/13 11:27, Pieter De Wit wrote:

quoted

Hi List,

Given the recent work done with techs like CUDA etc. - has the idea been
floated to use the video card for RAID parity calculations vs the CPU ?
Bitcoin and plenty others have shown the true speed of these cards. This
might be a cheaper version of a RAID card.

Cheers,

Pieter

I am almost certain that you /could/ use a graphics card to do parity
calculations faster than a cpu core.  However, even the newly proposed
multi-parity calculations are not a big challenge for a modern cpu.  A
bigger issue is getting optimal threading so that multiple cores (or at
least threads) can be used at the same time, and this work is well under
way already.  Once that work is completed, my guess is that I/O, cache
or memory bandwidth will be the bottleneck for big raid arrays rather
than cpu power - and using graphics cards will not help there.

David


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Ah - I see - I also thought it was multi-threaded, but, tbh, I never 
looked that hard into it. My question comes from the fact that I now 
have access to 32x750gig (and more if needed) drives on a fiber array. 
The down side is that I only have *old* CPUs driving the array. RAID5's 
sync speed (15 disks) is 8meg/second. Change the array to RAID10 and the 
sync speed is above 100meg/second.

I, naively perhaps, assumed the bottleneck to be the Intel CPU's which 
sparked this idea.

What about block level hashing ? (Unless this is already done and I just 
never knew it :) )

Cheers,

Pieter