Why is RDP in Windows Server 2003 so slow?

Question

Mikrotik

RDP Windows 2003 in VMware ESXi behind Mikrotik CHR NAT. There are a couple more servers next to it. Access to other servers is quite normal.

• VMTools has been updated.
  
• Ping 40-50ms.
  
• In Mikrotik, the netmap.
  
• VMware session does not slow down.
  
• Channel 50 Mbit
  

RDP
https://youtu.be/bU5QlK_e9Go

Session
https://youtu.be/e6d1uCt_drg

The session looks noticeably better, even though it's on the same channel.
Tried many recipes: LOS/dst-nat/change network card types... and much, much more.
I would appreciate any help.

Answer 1

Try turning off autotuning on the client (from the administrator in the CLI):

netsh interface tcp set global autotuninglevel=disabled

Answer 2

Try turning off hardware acceleration in your browser.
It is enabled by default in modern browsers. This affects how the application is rendered. RDP in this situation loses the ability to intercept specific changes on the screen, and in order to somehow show the client the current state of the application, it is forced to send the entire application every time with a whole picture, and not just the changes that have occurred. This leads to a slowdown, as each scroll movement sends the entire application image with each pixel change on the screen, instead of sending only the changed pixels.
RDP is fast when it only sends individual changes on the screen to the client, rather than the entire screen/whole area. At the same time, RDP is not suitable for applications that frequently update the image - RDP will be slow with them.
Some of these limitations are solved by RemoteFX, because transmits the image in a different way. With it, the experience of using applications will become noticeably faster.