ClearType in Remote Desktop

ClearType in Remote Desktop

  • Comments 31

One of the many new features Vista brings to Remote Desktop is ClearType support. Turn it on, you may be surprised at how much nicer the screen looks with fonts rendered in ClearType.  (If you’re not sure what ClearType is and why you should care, you may want to check out ClearType information for a better explanation than I can give.)

To turn it on, simply start up ‘Remote Desktop Connection,’ click the Options button and go over the to the ‘Experience’ tab. There along with such stalwarts as ‘Menu and window animation’ you’ll see two new checkboxes, one for ‘Font smoothing’ and one for ‘Desktop composition.’ Select ‘Font smoothing’ and TS to a Vista machine. We’ll talk about the ‘Desktop composition’ item at another time.) This only works when you connect to a computer running Vista or Longhorn Server. The client OS can be Windows XP, Windows Server 2003, or Vista but you must be running the updated ‘Remote Desktop Client’ in order to get the checkbox.

First, let’s get some questions out of the way. First of all, why did we call it ‘Font smoothing’ rather than ‘ClearType?’ The reason has to do with what these checkboxes actually mean. When any of the ‘experience tab’ checkboxes are selected, it doesn’t actually mean that any of the effects are turned on when you connect, rather they are not turned off.

In other words these checkboxes effectively mean ‘If possible, follow the settings the user would get if they were logging in locally.’ If a user doesn’t like ClearType and turned it off on their desktop, it wouldn’t get turned on automatically just because that user was coming in remotely with the ‘Font smoothing’ checkbox selected. One aspect of this approach is that if a someone uses standard font smoothing when they work locally, then that is what they will get remotely. Hence we decided to be strictly accurate and label the checkbox ‘Allow font smoothing.’

One reason we enabled ClearType with remote desktop is that with the advent of Windows Vista and Office 12, ClearType suddenly became much more important. For one thing, LCD monitors were becoming the standard. Also, ClearType was now the default in Vista. In fact, both the IE team and the Office team felt ClearType was important enough that they both over-ride the default on XP and render using ClearType even if it’s turned off by the system. If you really don’t like it, you can still turn it off, but a default install of IE 7 or Office 12 on XP will render in ClearType.

One corollary of this move to ClearType is that new fonts are being designed specifically with ClearType in mind. It’s a time-consuming process to create and tune new fonts and special emphasis has been given to the ClearType scenario over black and white rendering. The net effect is that the new fonts in Vista and Office 12 look particularly good when rendered with ClearType but they don’t look so nice when you don’t use ClearType. For more information about the new fonts, you may want to take a look at Jensen Harris' blog.

Now for a little history; back in the days of Windows XP the Terminal Services team had to decide what to do about ClearType. Back then ClearType was a new technology that wasn’t on by default. It wasn’t clear at the time how important this would be for Terminal Services scenarios but it was clear that remoting ClearType would consume more bandwidth. We simply decided to disable ClearType for remote sessions.

Fast-forward to 2006. As Vista took shape it was obvious that ClearType was becoming more important. All we really needed to do to enable ClearType is to remove the check in Windows. GDI will automatically render the characters as bitmaps and the bitmaps will work perfectly fine with RDP. The only problem with this approach is that our normal font rendering path is extremely efficient. Simply falling back to bitmaps could have a significant bandwidth hit. Because of this concern we didn’t want it on by default in the TS client. There are still a lot of slow links out there and we don’t want to make a simple upgrade consume additional bandwidth.

How bad is the performance hit? Depending on the scenario, the increase in bytes sent over the wire can be quite significant. In the final analysis it all comes down to what the user feels is an acceptable tradeoff.  From my own experience I connect to my desktop at work over a cable modem using Terminal Services Gateway every morning and I always turn on ClearType. I type about sixty words a minute and the performance is fine.
 
On the other hand, if you are an administrator of a server that’s sitting behind a slow WAN link, then the end-user tradeoff isn’t the important factor. Since that same line is shared by multiple services and multiple users, you care more about aggregate bandwidth usage of the server.  For this scenario we are planning on making the server side configurable with group policy.

In any case, try this out with your RC1 builds and let us know what you think.

Leave a Comment
  • Please add 1 and 2 and type the answer here:
  • Post
  • Will the availability of ClearType/Font Smoothing eventually be rolled out to Windows Server 2003?  This would greatly improve the readability of applications using small (8- and 9-point) fonts.

  • I didn't understand the part about bandwidth and ClearType.

    I presume that RDP can do either server or client

    side rendering.

    If the client is ClearType capable, and has the font definition, then why send a server-side rendered bitmap?

    Oh, and in general, what does RDP do about font definitions? Do RDP clients acquire font definitions from the server if they don't already have the font?

  • Along with many others, I find that I am unable to read an LCD screen with cleartype enabled. I recently replaced Vista on a new notebook with XP because of this problem. I tried everything including switching it off and using the cleartype tuner, but whatever I did I found that I couldn't disable it everywhere.

    Please give us a disable option that works throughout the system and also replaces the new 'cleartype embeded' fonts with suitable substitutes.  

  • Is there any trick to make ClearType feature work on WinXP RDP session (connected to WinXP as server) using RDP 6.0 client??

  • Can anyone please please tell me the activex for RDP on windows xp...i have either Msrdp.ocx located in Msrdp.cab  or RDCHost.RemoteDesktopClientHost and using both give me a class id error.I need to have the activex and invoke automation methods on it.Any help would be deeply appreciated!!!

  • Here are my weekly notes: Happy Thanksgiving Canucks! Here's a story on the success of Yahoo!...

  • PingBack from http://blogs.sepago.de/helge/2007/08/19/bandwidth-requirements-for-cleartype-over-rdp/

  • I need to use an application located on a terminal server that uses a modem to connect to fire and security alarm panels.  It does not appear that this is possible due to com port mappings while connected to terminal server (via rdp) using tcp/ip.  Help??

  • where can i find the basic information on Web Connection in Windows Vista?

  • Web Connection is availible in Windows Server 2008, but not in Vista.

    Rob

  • I use RDC all the time and was happy when 6.0 finally supported ClearType for XP machines. For months I've been using a Vista laptop to log in to an XP Pro desktop and font smoothing worked fine. Today, no. The remote machine thinks it's using ClearType (and it is, locally); toggling it off and on refreshes the screen. But the text display doesn't change, it's always without smoothing. It is set to run at 32 bit color but it comes in at 24 bit, not sure if that's related.

    I've checked every setting on both machines, deleted the rdp file, etc. I haven't found this behavior described anywhere. I reinstalled RDC 6.0 on the XP machine. I haven't installed anything much lately, just a new wireless mouse on the laptop that I can't imagine has any effect on RDC.

    Saludos, Mig

  • PingBack from http://www.ditii.com/2008/07/02/enabling-cleartype-in-terminal-services/

  • PingBack from http://www.laurentfalguiere.fr/articles/cleartype-et-la-virtualisation-de-sessions/

  • @Mark (February 13, 2007 2:47 PM): For the record, RDP does not do client-side rendering in Vista/2008.  It does glyph caching.  This can only be done with ClearType off.

    Client-side rendering is coming in Windows 7, according to slides from PDC 2008.

  • > Is there any trick to make ClearType feature work on WinXP RDP session (connected to WinXP as server) using RDP 6.0 client??

    Yes you can make ClearType work on a XP to XP RDP.

    http://digg.com/programming/ClearType_for_Windows_XP_Remote_Desktop

    If you read the comments at the bottom (of the CodeProject page) there also appears to be a way to do this by modifying the registry in XP SP3, though I have not tried that because the company I work for won't let us go to XP SP3 much less Vista.

Page 2 of 3 (31 items) 123