Here is a representitive run on my W2K system of a 1.5 and 10.5mb PUT.
Rounding down to 16k would seem to be the best compromise based on my
specific tests (in any case, anything other than 12k seems to be better for
whatever reason...), but it would be nice if this could be tested in other
environments using other OSes against different servers to be sure this is
the right thing to do for everybody.

bytes time(ms) snd buf select(ms) Avg select(ms)
----- -------- ------- ---------- --------------
1466946 1625 1024 1577 1.118440
1466946 1656 2048 1624 1.148515
1466946 1703 4096 1672 2.341737
1466946 1672 6144 1657 3.495781
1466946 1766 8192 1766 4.932961
1466946 1797 10240 1797 6.283217
1466946 23563 12288 23563 99.004202
1466946 1969 16384 1953 10.971910
1466946 13922 20480 13860 97.605634
1466946 11797 24576 11797 99.974576
1466946 8578 32768 8578 97.477273
1466946 1672 49152 1656 28.551724
1466946 4453 65536 4453 101.204545

bytes time(ms) snd buf select(ms) Avg select(ms)
----- -------- ------- ---------- --------------
10524483 11859 1024 11657 1.143740
10524483 11953 2048 11783 1.162032
10524483 12187 4096 12029 2.343007
10524483 11953 6144 11827 3.456166
10524483 12578 8192 12439 4.847623
10524483 13437 10240 13313 6.481500
10524483 170188 12288 169908 99.245327
10524483 15812 16384 15750 12.266355
10524483 101812 20480 101796 99.216374
10524483 81782 24576 81750 95.502336
10524483 61078 32768 61063 95.113707
10524483 14625 49152 14515 33.913551
10524483 31032 65536 30985 96.828125

                                                                                                                                 
                      Daniel Stenberg
                      <daniel_at_haxx.se> To: libcurl Mailing list <curl-library_at_lists.sourceforge.net>
                      Sent by: cc:
                      curl-library-admin_at_lists.sour Subject: RE: HTTP PUT performance issues
                      ceforge.net
                                                                                                                                 
                                                                                                                                 
                      12/10/2002 07:21 AM
                      Please respond to
                      curl-library
                                                                                                                                 
                                                                                                                                 

On Mon, 9 Dec 2002 RBramante_at_on.com wrote:

> So, the short of it seems that Win2k would prefer an 8k send size over a
> 20k send size given its druthers.

Hm.

Is this perhaps a multiple of 8K or possibly 4K? Could you try 16K or
something just for the fun of understanding this better?

I don't think there's any major disadvantage with going down to 8K but I'd
prefer to do a more moderate change.

Other reports (http://curl.haxx.se/mail/archive-2002-12/0038.html) indicate
that during some conditions on some platforms there's another problem
related
to that 20K buffer size that is fixed when going down to 10K...

Many thanks for all your time and hard work!

--
 Daniel Stenberg -- curl, cURL, Curl, CURL. Groks URLs.
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