So I've been running Vista from 1 laptop for 1 year and a desktop for the last 4 months or so. I mostly use the desktop for work related stuff. One day I needed to work form the laptop about 6 months, and all of my Citrix connections were slow. I'd open Outlook and I could see it paint the toolbars, the e-mail pane view would come 1 line at a time. I tried tweaking a few things on the laptop. Tried updating and tweaking the Citrix Presentation Server 4.0 servers. Nothing. Still slow. I googled all over the place (or so I thought) and found similar complaints but no solutions. I just gave up and went back to my Win XP box (what my desktop was at the time).
Fast forward a few months, and I'm forced to replace my Win XP with a new workstation running Vista. Same exact slowness. But now I notice that it depends on what environment I'm connecting to. All of my clients environments (Mix of Citrix Access Gateway (CAG), Secure Gateway (CSG), Altaddr, IPsec VPN, SSL VPN etc) work just fine. Just not our companies Citrix infrastructure. So I build a new CSG and a new PS 4.5 server. Same slowness. Now I'm banging my head against the wall.
I call Citrix and give them the facts above. The answer was to try and perform a direct ICA via VPN or Altaddr to eliminate CSG. Well I don't have control of the firewall and I know it will take awhile to get done. I get real busy. My wife has our 3rd kid. And I just forget about it. Until now...
So I start googling again. Then I finally hit the right search words "RDP slow vista". I tried "terminal server slow vista", "citrix slow vista", "citrix performance vista", and tons more. But never tired RDP (AKA Remote Display Protocol). (PS hopefuly that teaches people writing articles to put acronyms, full spellings, and nicknames for technologies so that they can indexed/searched with as many common terms as possible).
Anyway not to make this story any longer, I finally ran into this command that has saved me from the pits of slowness hell.
netsh interface tcp set global autotuninglevel=disabled
It must be run from the command line as an Administrator and may require you to Allow its execution (thanks to User Account Control feature of Vista). It should return OK if it completes correctly.
Props to Tom Keating @ http://blog.tmcnet.com/blog/tom-keating/microsoft/remote-desktop-slow-problem-solved.asp for getting it solved. Don't know what AutoTuning really enables for most home users, but I haven't noticed any illl effects otherwise. Some more googles on that command have shown slowness with Outlook 2007, File Transfer, and more. Hopefully this saves people some time.