HTTPS Download Slow

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atlantika
Posts: 2
Joined: Fri Dec 25, 2009 9:31 pm

HTTPS Download Slow

Post by atlantika »

Hello,

when i download one File with 300MB or bigger via HTTPS my Speed is only: 250kb/s. With HTTP or FTP my Speed is 3,2 MB/s. When i use HTTPS my CPU is ~5%. I use Windows 7 64bit Professional on VMware VSphere 4.0U1 with 2GB RAM and 1 vCPU. The Storage is FiberChannel from EMC with Raid 10 (SAS 15500rpm). I use no Hardware Firewall Appliance only the Windows Firewall. The Speed is the same when i disabled the WIndows Firewall. I use a Public Thawte SSL123 Cert. My connect to the Internet is a Syncrone 40 MegaBit DarkFiber Line.
atlantika
Posts: 2
Joined: Fri Dec 25, 2009 9:31 pm

Re: HTTPS Download Slow

Post by atlantika »

My Wing FTP Server Version is 3.2.4
FTP
Site Admin
Posts: 2072
Joined: Tue Sep 29, 2009 6:09 am

Re: HTTPS Download Slow

Post by FTP »

Your HTTPS download speed is 250Kb or 250KB? if it is 250Kb, maybe something is wrong.
Powl1337
Posts: 1
Joined: Tue May 25, 2010 9:12 am

Re: HTTPS Download Slow

Post by Powl1337 »

i've the same problem with https AND ftps (explicit and implicit)... ~250kbyte/sec
funny thing is: when i start to dowload 2 or 3 files simultaneously the downloadspeed of the client will double respectively triples and so on...

when i use unencrypted filetransfer, one download is enough to get the maximum out of my Internet connection...

Server 3.4.5@win7 pro 32bit
FTP
Site Admin
Posts: 2072
Joined: Tue Sep 29, 2009 6:09 am

Re: HTTPS Download Slow

Post by FTP »

Hi,
When using SSL, it will take extra CPU usage and some time to encrypt/decrypt the data. So the 5% CPU mentioned is quite normal and the download/upload speed can be a little slower than unencrypted file transfer. But in your case, the speed difference is too large. I have tested both on "real" OS and the virtual box. The ratio of download speed between http:https on "real" OS is 1:3, and on virtual box is 1:6. The problem also has something to do with the ssl certificate bits (1024, 2048 or 4096). The bigger the bits, the more secure the transfer will be, but this also means more CPU usage and the speed can be really slow.

Try to move your server from Virtual Box to the "real" OS, and test it.

Also, you can test the speed of our demo server using http and https on your side. Then tell us the result.
Please refer to: http://www.wftpserver.com/onlinedemo.htm
langj
Posts: 5
Joined: Thu Feb 16, 2017 2:37 pm

Re: HTTPS Download Slow

Post by langj »

On the Demo Server is the Speed 10MB/s
Any idea why my Speed is Maximum 2MB/s over HTTP with a 200 Mbit Upload Line?
I have a Sophos Firewall.
Thank you
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