From: Frank Steiner <fsteiner-mail@bio.ifi.lmu.de>
Subject: Performance udp vs. tcp
Date: Mon, 23 Aug 2004 11:57:40 +0200
Sender: nfs-admin@lists.sourceforge.net
Message-ID: <4129BF94.20902@bio.ifi.lmu.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
To: nfs@lists.sourceforge.net
Errors-To: nfs-admin@lists.sourceforge.net

Hi,

I just ran some bonnie++ tests to measure the nfs performance of udp vs.
tcp, expecting tcp to be better (after reading this list and some newsgroups).
Amazingly, it turned out that udp with rsize/wsize 16k was the best, taking
the average over all tests. tcp was a little better in some of the large-file
tests, but especially with creating/stating/deleting 16 thousands of small
file, sequentially and randomly, udp was better than tcp in every test
(between 5-15 % faster). I rann all the tests also with differenct tcp windows
sizes, and a larger window size speeded up udp and tcp more or less in the
same way.

I was very amazed by this, but I guess this could be caused by our network,
which is a fully switched "100mbit for client/1gbit for servers" network,
so we have almost no packet loss.

If I got the discussions on the list and in the newsgroups right, on a
lossy network udp would slow down due to the packet loss and resends.

So, can my result be correct for a really fast and stable network? Or is
it some "bonnie++ likes udp" effect? :-)

cu,
Frank

-- 
Dipl.-Inform. Frank Steiner   Web:  http://www.bio.ifi.lmu.de/~steiner/
Lehrstuhl f. Bioinformatik    Mail: http://www.bio.ifi.lmu.de/~steiner/m/
LMU, Amalienstr. 17           Phone: +49 89 2180-4049
80333 Muenchen, Germany       Fax:   +49 89 2180-99-4049


-------------------------------------------------------
SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media
100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33
Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift.
http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285
_______________________________________________
NFS maillist  -  NFS@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs