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From Phillip Susi <>
Subject Re: SSL downloads faster than non SSL?
Date Tue, 02 Aug 2005 21:54:22 GMT
That's what it was, thanks.  Say, the name says 'Sendfile' but that 
doesn't exist on win32.  Does apache call TransmitFile() instead or does 
it use some very poor library emulation of sendfile()?  If it were using 
TransmitFile() I would expect it to not have any trouble saturating the 

FYI, I used wget to download the file without SSL and with sendfile 
disabled and it took 55 seconds and reported a rate of 11 MB/s.  I used 
a copy command to download the file from the command prompt via the SMB 
mapped drive and it took 90 seconds.  I wonder what the heck the deal is 
with all that fancy kernel mode redirector stuff not working out the way 
they designed?

I don't even see why the option for sendfile should exist on the win32 
build, seeing as how you can achieve the same performance using memory 
mapped zero copy overlapped IO, which also would work with non disk 
files, such as an SSL encrypted connection. 

One of these days I'm going to have to take a little vacation from work 
and write an MPM to do just that. 

Rici Lake wrote:

> Try setting
> EnableSendfile off
> in your apache config file and rerunning the tests. There have been 
> other reports of surprisingly slow transfer speeds with sendfile 
> enabled on Windows. This won't affect SSL, of course, since the SSL 
> transfer cannot use sendfile.

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