File Transfer low speed from Server to Client

[Zweiblum]

I am using UltraVNC 1.2.1.1 on Server and Client side!

When i transfer data from Client (my PC) with UltraVNC-Viewer(1.2.1.1) to the Server (Remote PC), then the file will be copied with maximum speed (100Mbit for example).

But when i copy the file back over the same File Transfer dialog from Server (Remote-PC) to Client (my PC), then the speed is always limited to exactly 520kb/s!
Why? I can't find any settings to increase this value. And the tips in other forums haven't helped.

By the way, it's always the same effect, regardless of (newer) VNC-versions, OS's (like Windows7-64Bit, Windows10, etc.)!

[Rudi De Vos]

local lan, internet ?

[Zweiblum]

I have tested it on both sides!

Local LAN: i can say, that the effect occurs always to 100%. We have here 100-1000MBit connections!
Internet: It's hard to say, therefore i have to find first someone, which has more than 4 MBit upload speed! But, also with internet tests, i have never seen more dowload speeds than 500 kbyte/s ~ 4000kbit (~4MBit). The most have 200-400kbyte/s.

By the way: The results of transfer speeds, which i tell you, i always take from the File Transfer dialog (UltraVNC) on the right side of the progress bar, while i copy something!

[Rudi De Vos]

I need to test it, but transfer from server to viewer is slower because the FTtransfer packakets need to merge with the screen updates, but didn't know it's that slow. Does minimizing viewer window makes it faster ?

[Zweiblum]

I have tested the minimizing behaviour with running wireshark in background. Absolutely no effect!

[Zweiblum]

Do you have just tested the speed of the connection in LAN and found something out?

[sockd]

Hi,

I have the same Problem here...

General configuration:
- LAN
- Connected 2 PC´s directly without Switch.
- UltraVNC 1.2.1.2 on both sides.
- Both PC´s have same Intel SSD

"Server" configuration:
- Windows 10 Professional
- 1GBit Intel PCI NIC
- Tested with sendbuffer=1500/sendbuffer=8192 and MaxCPU=100 in ultravnc.ini under [admin]

"Client" configuration:
- Windows 7 Professional
- 1GBit Intel onBoard NIC
- Tested with sendbuffer=1500/sendbuffer=8192 and MaxCPU=100 in ultravnc.ini under [admin]

Testcases and results (all initiated from Client):
- Transfer File from Server to Client with FTP: ~76mb/s
- Transfer File from Client to Server with FTP: ~88mb/s
- Transfer File from Server to Client with UltraVNC-Filetransfer: ~512kb/s
- Transfer File from Client to Server with UltraVNC-Filetransfer: ~8001kb/s

I already tried some Registry-Fixes for TCP, but it seems, only UltraVNC has the Problem.

Any Tips/Ideas?

[Rudi De Vos]

filetransfer
viewer->server higher speed

test viewers

http://www.uvnc.eu/download/1215/vncviewer_1215.zip

[sockd]

Thanks for your reply, Rudi.

But the problem is server --> viewer ...

[Zweiblum]

Thank you Rudi for your test, but how "sockd" mentioned, the problem is from server -> viewer! This i wrote in the first notice too!

By the way, for me it's very important to copy with maximum speed from server -> viewer and i would be glad, if the problem will be fixed soon, because it's not funny to copy databases, which have sometimes up to 5 GB(!), with a maximum speed of 500kb/s .

[Rudi De Vos]

This should be fixed in a later forum update
http://forum.ultravnc.info/viewtopic.ph ... 31b#p10203

Please test.

[Zweiblum]

Thank you. It works with your testclient/server .

When do you think, it will fixed in next releases?

[Rudi De Vos]

Should be in July.