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Re: Windows users! Help us test upload performance tuning?

From: Jan Ehrhardt via curl-library <>
Date: Wed, 15 Aug 2018 22:51:34 +0200

Daniel Stenberg via curl-library (Tue, 14 Aug 2018 09:39:21 +0200 (CEST)):
>I think its time we run some tests in an orderly fashion with different upload
>buffer sizes and collect some numbers...

Feedback on some informal upload tests from Phoenix, Arizona to Amsterdam, NL.
High speed connection. Upload around 200 Mbits/s according to, but
a latency of 200ms. My tester uploaded a 178MB mp4 file first with the unpatched
iPad app (libssh2, not curl), then with a patched iPad app, then used Filezilla
and last, but not least a patched curl.exe.

Network connection: about 200 Mbits/s up, 200ms latency (
Test file: 178 MB mp4
Protocol: sftp

iPad app 32 KB libssh2 buffer: 2147 seconds
iPad app 320 KB libssh2 buffer: 737 seconds
Filezilla (out-of-the-box) : 967 seconds
curl x64 512 KB upload buffer: 1154 seconds

% Total % Received % Xferd Average Speed Time Time Time Current
                                 Dload Upload Total Spent Left Speed
100 176M 0 0 100 176M 0 156k 0:19:14 0:19:14 --:--:-- 195k
100 176M 0 0 100 176M 0 156k 0:19:14 0:19:14 --:--:-- 156k
start:2.437000 total:1154.047000

Speed sometimes as low as 125K, said my tester.
At the same time another user from the same network was uploading a 289 MB mp4
file in 1106 seconds, using bash/lftp. At the same speed that would have been
681 seconds for the tester's 178 MB file. bash/lftp may be some 8% faster than
the patched iPad app.

Received on 2018-08-15