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treo

Do you have any pointer on how you've profiled Neanderthal during development?

When I originally set out to compare ND4J and Neanderthal, I've ran into the issue that I bottomed out at: they basically both call MKL (or Openblas) for BLAS operations.

Awesome! I didn't expect you to write that blog post so soon. It will be interesting to find out where the differences (beyond the 'f' ordering thing) are that make Neanderthal so fast, since when I originally started the comparison, both basically boiled down to calling MKL through JNI.

For completeness sake, could you also provide some information about your machine specs and operating system (and if on linux your glibc and kernel version)?

It looks like while converting from my benchmarking code you've dropped the 'f' when creating the resulting array.

https://github.com/treo/benchmarking_nd4j/blob/master/src/ma...

The difference is rather huge with the newer versions of nd4j.

While the numbers in the following gists do not contain the measurements I took for neanderthal, they do contain the numbers that I got for ND4J.

Without f ordering: https://gist.github.com/treo/1fab39f213da26255cf4f75e383ff90...

With f ordering: https://gist.github.com/treo/94fe92c9417b5c8b24baa12924a35b0...

As you can see something happened in the time between the 0.4 release (I took that as the comparison point since that was when I ran my own benchmarks the last time) and the 0.9.1 release that introduced additional overhead.

Originally I planned to create my own write-up on this, but I wanted to first to find out what happened there.

Given that ND4J is mainly used inside of DL4J and the matrix sizes it is used with usually are rather large, the performance overhead difference that I've observed there for tiny multiplications isn't necessarily that bad, as the newer version performs much better on larger matrices.

Re:OVH Incident in Strasbourg on Thursday November 09, 2017 @04:55AM (#15661151)
Looks like they are starting to come back up. My VPS is accessible again.
Re:TDD django Tutorial on Monday May 28, 2012 @05:02PM (#4034915)
Your tests, or the output they produce, look awesome. Can you elaborate on your setup? Just today I was looking for an up to date introduction for testing in django, but could only find some older blog posts. So I would be glad if you could detail your setup a bit.
The swiss have a direct democracy and are not a theocracy.
Re:Memristor cell scaled down to 10nm on Thursday December 15, 2011 @03:44AM (#3355456)
Re:Python 3 implementation in Haskell on Tuesday November 08, 2011 @09:13AM (#3210759)
Last commit on August 04, 2011. https://github.com/bjpop/berp
I would also love a more ebook reader friendly format like Mobi or ePub. I still bought it, because I might be able to convert it to something usable for myself, but a version that is actually made for ebook readers (like the sony prs-650 that I have myself :)) would be even better.
Re:Pirate Party Germany now at 8% in nationwide polls on Wednesday October 05, 2011 @02:10PM (#3076796)
http://translate.google.com/translate?sl=auto&tl=en&...

This are their current goals. They want to allow private copying. So selling the copy would still be illegal.

Concerning patents: "We reject patents unanimously onto organisms and genes on business ideas and also to software"

Just in case that anybody cares: There are more or less simple ways to use cgi with nginx. Just see here: http://wiki.nginx.org/Fcgiwrap or http://wiki.nginx.org/SimpleCGI
Re:Facebook account locked after "unlocking" Timeline? on Sunday September 25, 2011 @06:40AM (#3035552)
This happens every time they declare an app as fraudulent.
Re:Show HN: A browser-agnostic replacement for Pixel-Perfect on Friday September 23, 2011 @04:04AM (#3029227)
I didn't know what Pixel-Perfect is and your README didn't tell me much about what Perfect-Pixels does. I found a short description of it in the project description, but you definitely should add it to your README and this post.
Re:Tell HN: the iPad is hot in small businesses on Monday September 19, 2011 @08:20AM (#3013223)
I wonder, why haven't you just submitted it as a url?
Re:SingleHop Are Cheats on Friday September 16, 2011 @09:06AM (#3004273)
That would take forever, at least on my system, as I don't really have a lot of entropy available. Just for kicks I have started this when I began writing this reply. And now I have the huge amount of 200 Byte in this test file. So thats about 10 bytes per second.

But if you take /dev/urandom you can get quite a bit more. On this system it is about 7Mbyte/s.

Re:Why Ubuntu Linux is now ready for primetime on Saturday August 27, 2011 @09:28AM (#2931413)
My Thinkpad T400s runs at 8W/h when tuned with powertop2 (3g disabled, wlan disabled). But as the battery only has a capacity of 43Wh it only comes up to a bit more then 5 hours.

I could however replace the disk drive for another battery and have about 9 hours of run time with it.

I found it quite easy to read. Usually I use my readability bookmarklet on almost everything, but this time I didn't need it.
Re:Can Turntable.fm Survive Its Popularity? on Thursday June 30, 2011 @02:52AM (#2712955)
> We're very sorry, but while we would love to let you in and rock out with us, we need to currently restrict turntable access to only the United States due to licensing constraints

It looks like they have killed everything but USA access.

Re:A brief experiment with PyPy on Thursday May 12, 2011 @12:12PM (#2541074)
No, tpc-uva is a bit more than what I need right now. I might use it later on when I have decided on any single algorithm that I want to test in a more realistic environment. Because changing the caching algorithm that postgres uses isn't as easy as doing so in a standalone python simulator, I will have to be sure that I want to do that. I have already tried that before and it is a lot harder and takes a lot more time.
Re:A brief experiment with PyPy on Thursday May 12, 2011 @11:13AM (#2540831)
That 3x speed up is about the same that I have seen with my code. I'm currently writing a database cache simulator to try different algorithms with it, and if I want to have anywhere near realistic results I have to use realistic access traces.

Tried it today with a tpc-c trace which has about 500 million accesses. The result: CPython would have run for about 90 minutes (I stopped it after 30 minutes, and began to look for a speedier possibility), PyPy only took 22 minutes.

Re:Ask HN: Cheap Bulk Storage? on Saturday May 07, 2011 @12:40PM (#2524007)
It's a shame that nobody has a chassis like the sun fire 4500 anymore. The closest I could find is a 5U Thinkmate STX XA48-2510 which would work out at about 32 cents/GB.
Then you might want to read the following links: http://www.paulgraham.com/spam.html http://www.paulgraham.com/better.html

They describe how bayesian filtering works and how to use it to detect spam automatically.

Re:Favorite office desks and chairs? on Wednesday April 27, 2011 @06:02AM (#2488941)
I have the same desk, a Steelcase Please they work out quite nice.
http://www.daemonology.net/hn-daily/ This is probably what you want.
Re:Nginx 1.0.0 is out on Tuesday April 12, 2011 @09:52AM (#2437159)
I ran into a problem with a tcp connection to php-fpm just some weeks ago: The Server served requests at a rate of about 400req/s for some time without a single problem, until I ran out of useable ports. You won't have this problem with sockets.
Re:Why designers need to stop moaning about 99designs.com on Monday March 28, 2011 @11:33AM (#2378713)
The big difference is that on Swoopo you lose your investment if you don't win. But on 99designs you can still keep the design and get the feedback that it wasn't the right thing, and what was. Even if you don't get the job, you still get the practise and feedback. So I think there is at least some benefit.

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