Why are remote desktop clients (RDP) very slow on my Mac?

Solution 1:

I don't know for sure, but I've heard the same complaint. A theory is that on Mac (and Linux) the full images are sent over the network, whereas on Windows some higher level drawing commands are sent, at least for some parts of the screen.

It'd be interesting to try running Remote Desktop Client for Windows on the Mac (or Linux) using Wine, and compare performance this way.

Solution 2:

I had this problem on my MacBook Pro with this:

sudo -s
sysctl net.inet.tcp.delayed_ack=0

To make it stick between reboots, add it to /etc/sysctl.conf with…

echo net.inet.tcp.delayed_ack=0 >> /etc/sysctl.conf

Solution 3:

I had this very issue but the interesting thing is that the RDC to this machine had been working fine some days before – but all of a sudden, over a gigabit network I could see each bitmap block coming across. I tried some other solutions such as executing:

netsh interface tcp set global rss=disabled
netsh interface tcp set global autotuninglevel=disabled

from an elevated commas prompt as suggested here: Vista Remote Desktop Connection Client Slow Delay or Disconnect When Connect to Windows Server 2003 SP2 x64 Edition RDP. That didn't work though.

Then I twigged what had changed since it last worked. I had re-enabled by realtime virus checker (in this case ESET Cybersecurity). I turned off realtime file system protection and instantly RDC and (and also SplashTop desktop, which does the same thing) got back to normal speed.