Re: Wanted: Secure-delete utility for Linux

Michael Shields (shields@msrl.com)
23 Dec 1998 08:32:37 +0000

In article <199812230309.AAA05174@sleipnir.valparaiso.cl>,
Horst von Brand <vonbrand@sleipnir.valparaiso.cl> wrote:
> There are faster methods, but I'd guess that the I/O time swamps everything
> else.

Don't guess; measure.

$ time ./a.out | dd bs=1048576 count=10000 of=/dev/null
0+10000 records in
0+10000 records out
Broken pipe

real 0m4.010s
user 0m3.560s
sys 0m0.240s

Your program generates roughly 2.5 GB/s on an unloaded Celeron 333.
(gcc 2.7.2.3, -O2) This exceeds the RAM bandwidth.

There is no need to optimize the generator speed further.

-- 
Shields.


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