Re: Increase BUFSIZ to 8192

From: John-Mark Gurney <jmg_at_funkthat.com>
Date: Wed, 13 May 2015 01:03:42 -0700
Poul-Henning Kamp wrote this message on Tue, May 12, 2015 at 06:31 +0000:
> --------
> In message <20150512032307.GP37063_at_funkthat.com>, John-Mark Gurney writes:
> 
> >Also, you'd probably see even better performance by increasing the
> >size to 64k, [...]
> 
> easy:
> 	8K on 32bit
> 	64k on 64bit

Sounds good to me...  Just for people who care... I did a quick set of
benchmarks on sha256.. This is using my preliminary patch to use sse4
optimized sha256...  But this should be the same for others...

The numbers in ministat output are the time in seconds it takes my
3.4GHz AMD A10-5700 APU running HEAD to process a 512MB file, so lower
numbers are better..  I've processed them into easier to read format:
BUFSIZ:	145MB/sec
8k:	193MB/sec
16k:	198MB/sec
64k:	202MB/sec
128k:	202MB/sec
-t:	211MB/sec

x def.times
+ 8k.times
* 16k.times
% 64k.times
# 128k.times
+-------------------------------------------------------------------------+
|#%  *    +                                                             x |
|#%  *    +                                                             x |
|#%  *    +                                                             x |
|##  *    +                                                             xx|
|A|  A    A                                                            |A||
+-------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x   5          3.53          3.55          3.53         3.536  0.0089442719
+   5          2.65          2.66          2.65         2.654  0.0054772256
Difference at 95.0% confidence
        -0.882 +/- 0.0108161
        -24.9434% +/- 0.305885%
        (Student's t, pooled s = 0.0074162)
*   5          2.58          2.59          2.58         2.584  0.0054772256
Difference at 95.0% confidence
        -0.952 +/- 0.0108161
        -26.9231% +/- 0.305885%
        (Student's t, pooled s = 0.0074162)
%   5          2.53          2.54          2.54         2.538   0.004472136
Difference at 95.0% confidence
        -0.998 +/- 0.0103127
        -28.224% +/- 0.29165%
        (Student's t, pooled s = 0.00707107)
#   5          2.53          2.54          2.53         2.532   0.004472136
Difference at 95.0% confidence
        -1.004 +/- 0.0103127
        -28.3937% +/- 0.29165%
        (Student's t, pooled s = 0.00707107)

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."
Received on Wed May 13 2015 - 06:03:50 UTC

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