Puneet

Graywulf is interesting:

http://www.sdss.jhu.edu/~szalay/papers/GrayWulf-SC08.pdf

https://arxiv.org/abs/1308.1440

The first paper mentions system balance. The ratio of IO bandwidth to bandwidths  at other levels of the memory hierarchy is often looked at, (sometimes also to floating point operations). File systems are typically shared, so some care may be needed in attributing performance on a file system to a single computer.

Regards,

Benson

On 8/10/19 7:37 PM, Patrick Farrell via IO-500 wrote:
Puneet,

I am familiar with Amdahl’s Law, but I am not familiar with Amdahl IO and cannot find anything with Google.  Do you have a reference for this, explaining how it’s computed and what it’s supposed to mean?  It is hard to see how the Amdahl’s Law - that speed up from parallelism is limited by the serial portion of a program - has any relationship to the I/O 500 benchmarks, which are concerned with a series of specific and separate benchmarks.  The various benchmark numbers are not part of a single parallel program, and so do not have the sort of relationship where Amdahl’s Law is relevant.

Regards,
Patrick
From: IO-500 <io-500-bounces@vi4io.org> on behalf of Puneet Bakshi via IO-500 <io-500@vi4io.org>
Sent: Friday, August 9, 2019 11:11:47 PM
To: io-500@vi4io.org <io-500@vi4io.org>
Subject: [IO-500] Why "Amdahl IO no" is not part of IO500 metric?
 
Dear Sir/Madam,

I am Puneet from India and is a student in Indian Institute of Technology Guwahati.

I read about IO500 and (Amdahl) Balanced Systems (such as GrayWulf). But, after doing some math, I found some of the top IO500 systems have  very low Amdahl IO number. Why IO500 does not include (and publish) Amdahl IO number as one of its metric? Looks like I am missing something but I do not know what. Please help me understand this paradox. This question just came out as an academic curiosity and not to endorse or refute any system. Please help me understand more.

Regards,
Puneet
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