Performance of scp with OpenSSH - 5.1p1

Damien Miller djm at
Tue Aug 26 03:03:39 EST 2008

On Mon, 25 Aug 2008, S, Senthilprabu (NSN - IN/Bangalore) wrote:

> I do not see any higher throughput (20%) with the 5.1p1 (with UMAC-64)
> than 4.5p1. The above results clearly says it is not increasing the
> performance by 20%. Did I something here?.

Did you enable UMAC 64?

scp -oCiphers=arcfour256 -oMACs=umac-64 at ...

I measured a 20% performance improvement on my system on
localhost->localhost transfers.

BTW, it is good that your results show a 10% improvement *without* the
use of UMAC 64.


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