Bug 44363

This is a question that should be tried first on a user-support forum like the
users@httpd.apache.org mailing list before filing a bug report.

(Before you post to the users list, try the standard win32 trick:
EnableSendfile off
EnableMMAP off
Win32DiableAcceptEx
)

(In reply to comment #1)
> This is a question that should be tried first on a user-support forum like the
> users@httpd.apache.org mailing list before filing a bug report.
> 
> (Before you post to the users list, try the standard win32 trick:

another thing to try 

SendBufferSize 10000000

(number is probably overkill, but sufficient for testing the theory; I saw a
complaint recently that Apache on Windows was using much smaller TCP windows
than IIS; I don't think "ReceiveBufferSize 10000000" would help here)

I tried all of the tricks suggested with no significant success.  I did notice 
that EnableSendfile off did double my download speeds to 700Kb/sec, but 
unfortunately, the other options didn't make a difference.  I had great hope 
for the ReceiveBufferSize, but it seems that my Window Size is sufficent.

I've noticed that file download sent via PHP "streaming" using the PEAR 
HTTP_Download package are sending at full speed.  Just static content is 
slowed.

Just to verify...

You did confirm that EnableSendfile Off speeds things up?  Does EnableMMAP Off
further change the performance for better or worse?

EnableSendfile Off speeds up static file transfers from about 350Kb/sec to 
750Kb/sec.  No other setting helps.  
PHP streaming transfers max out the visitor's connection speed - for me it is 
about 2MB/sec.

(In reply to comment #6)
EnableMMAP Off had no noticable effect.

If all these dont work:

EnableSendfile off
EnableMMAP off
Win32DiableAcceptEx
SendBufferSize ...

Then this is one last thing to try (it did the trick for me on W2k3 R2):
Set in your Windows registry

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Afd\Parameters

DefaultSendWindow
DefaultReceiveWindow

To something like 65535. You'll probably have to create the DWORD values. Reboot afterwards and that should do the trick.

It appears that Apache fails to set the buffer size (without printing warnings) or its setting is ignored by Windows for some reason.

Please let us know if the global send buffer size was different then the directive.  I've observed this myself.

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