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I am working on top500 supercomputer database.(http://www.top500.org/)

Rmax is maximum performance 
RPeak is theorotical maximum performance.

Does Ratio of Rmax to RPeak results to something? Like say efficiency? or anything which could say something about a supercomputer.

Could it be something like Lie factor?

ilse2005
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Ojas Kale
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    Check this answer too: http://stackoverflow.com/a/26012275/196561 RPeak is theoretical maximum of hardware (frequency * number of double precision FPU * FPU width); and Rmax is maximum achieved on HPL benchmark (3rd generation of linpack benchmark). Linpack stores data in memory and sends it over network, so it can't reach theoretical maximum; 50-80 % are typical and 90% are very good for large machines. Main operation in Linpack is GEMM - matrix-matrix multiply which is highly optimized on most platforms; but mem access/copy/send will limit percentage. – osgx Jun 24 '16 at 14:44

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Rmax is determine by HPL benchmark. Details aren't always published, unfortunately, but in most cases, the problem dimension requires a decent fraction of total memory.

Rpeak is determined by multiplying the number of floating point units (usually vector) per processor times processor count times the number of floating point instructions that can be issued per second. This is a bit hard today because of frequency variation.

The ratio can be viewed as an efficiency factor, although it may not be productive to use the result for assigning value to systems. 75% of 1000 is the same as 100% of 750, and if they have the same dollar and power costs, what difference does it make?

I tend to view the combination of Top500, Graph500 and HPCG results as a more robust way to compare systems, but one cannot ignore power and dollar costs if one pays for systems (most users do not, at least directly).

Jeff Hammond
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