[Beowulf] Parallel programming for Xeon Phis

[John Hearns]

Doug,
I read your paper only yesterday and found it very perceptive regarding the generations of supercomputers we have been through.

Following on from what you say about companies having teams which would optimise codes for customers, in return for sales,
remember that compilers were originally given away free with mainframes.
OK, I guess that the state of the art for a FORTRAN Compiler in the 60s is pitiful compared to the sophisticated compilers we have today.
But I guess that the curves have crossed - the hardware these days is powerful and readily available.
It is the software stack of optimising compilers, debuggers and dare I say it, the experts who can make the machines sign and dance which are the expensive part now.


ps. I have told this one before. From the Devils Dictionary:
Debugger:  (noun)   The person who sold you the system  (Irish)



-----Original Message-----
From: Beowulf [mailto:beowulf-bounces at beowulf.org] On Behalf Of Douglas Eadline
Sent: 24 August 2016 17:32
To: Prentice Bisbal <pbisbal at pppl.gov>
Cc: Beowulf List <beowulf at beowulf.org>
Subject: Re: [Beowulf] Parallel programming for Xeon Phis


Understanding your code and optimization for HW is where future progress in HPC is going to come from. Throwing more and more hardware at a problem has a diminishing return.

I recent wrote a paper for InsideHPC/Mellanox about the co-design process where machine designers, coders and application specialist are literally in the same room working on new systems (Summit and Sierra)

Back in the day (okay I said it), when there were just a handful of supercomputer companies, each company would have whole teams that would optimize potential customer codes for their machines. On many customer codes they would get huge speedups (the top 20 known packages were well understood on the target machine).

I was convinced at one point that customers just roughed out the code, and let the companies optimize for them. But then the customer was plunking down 6-7 figures for a system so code optimization was probably the cheap part of the sales effort.

Okay, now get off my lawn.

--
Doug


>
> his is an old article, but it's relevant to the recent discussion on
> programming for Xeon Phis, 'code modernization', and the speedups
> 'code modernization' can provide.
>
> https://www.hpcwire.com/2015/08/24/cosmos-team-achieves-100x-speedup-o
> n-cosmology-code/
>
> --
> Prentice
>
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--
Doug

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