cURL / Mailing Lists / curl-library / Single Mail


Re: Speed comparison wget vs. curl (HTTPS/HTTP1/GnuTLS)

From: Daniel Stenberg <>
Date: Thu, 30 Jun 2016 18:54:44 +0200 (CEST)

On Thu, 30 Jun 2016, Tor Arntsen wrote:

> Yes, it's exactly the same tests as we've been doing. This is the Debian
> curl package, seems to be gnutls:

This seems to be something about how the Debian curl or libcurl are built.

Here's comparing debian 7.47.0 curl vs my own local 7.50.0-DEV build, both
using the exact same GnuTLS version 3.4.13:

$ time curl --tcp-nodelay -s -o/dev/null
real 0m0.102s
user 0m0.076s
sys 0m0.008s

$ time ./src/curl --tcp-nodelay -s -o/dev/null
real 0m0.036s
user 0m0.016s
sys 0m0.004s

Specifically, it seems to be about how it finds the CA certs and reading them.
I run strace -tt on the debian build and my own build and compare:

My build:

$ grep BEGIN my-strace-log
18:47:44.950234 read(5, "-----BEGIN CERTIFICATE-----\nMIIE"..., 270336) =

The Debian build:
$ grep -c BEGIN debian-strace-log

See, it reads no less than 525 separate files. No wonder that takes time. How
much time? I think most of the extra time can be explained by this:

$ grep BEGIN debian-strace-log | head -1
18:47:12.015910 read(5, "-----BEGIN CERTIFICATE-----\nMIIE"..., 270336) =
$ grep BEGIN debian-strace-log | tail -1
18:47:12.149284 read(6, "-----BEGIN CERTIFICATE-----\nMIIF"..., 4096) = 1948

In this invoke over 130 milliseconds just to finnish reading the CA certs! (I
assume the slightly slower execution here is due to the stracing itself)

List admin:
Received on 2016-06-30