GPG & Floating point?

[Werner Koch]

On Mon, 17 Dec 2007 17:04, alan.watt at per-se.com said:

> Can anybody answer the question whether GPG uses any floating point 
> instructions during decryption?

Nothing serious.  There might be a few used with printf or calculation
of file sizes but that won't harm the performance.

> I'm running some performance tests on a 4-core SPARC T-2000 verses my 
> current production environment, and GPG decryption performance is 
> nowhere near as improved as I would expect.  The actual performance I 
> get per thread is about equal to an old 296 MHz Ultra-SPARC II 

It depends on what you are measuring: Is it about bulk operation
(processing large files) or the performace of the public key operations
on short data.  The latter can be improved by using the assembler code
for the big integer math; check out what links are set in mpi/.  Bulk
encryption is limited by the encryption code and the SHA-1 hash
function.  Are you using the same algorithms on both machines?


Shalom-Salam,

   Werner



-- 
Die Gedanken sind frei.  Auschnahme regelt ein Bundeschgesetz.