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Secrets for Optimizing Flash Performance Part 2

Friday, 14 December 2007 by Michel Roth

In addition to Derek Thorslund's first article on the "secrets for optimizing flash performance" he's posted another article that continues on the secret path.

This time around, Derek mentions the "Queuing & Tossing feature" of Citrix Presentation Server 4 and higher. This feature shows up in the management console as "Discard queued images which are replaced by other images" or "Discard redundant graphics operations", depending on which version of Presentation Server you're running. For future reference:

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Derek shares some very interesting details (that Citrix should have made very public prior to release of CPS 4.5 in my opinion) about this Queuing & Tossing feature: "The tossing algorithm was enhanced in Presentation Server 4.5 (Ohio) to look for more graphics constructs. The tossing algorithm now uses a 1-bit-per-pixel map of the session screen. And it can detect complete self-contained 'frames'. As a result, Thinwire will either send the entire frame to the client as a self-contained entity or toss it completely. These improvements to the tossing algorithm further reduce the amount of data that needs to be sent over the wire. Along with reduced network bandwidth consumption, network efficiency (data bytes per frame) is increased. And the user experience is better because the entire frame gets updated at once rather than in pieces."

In addition he teaches us that in PS 4.5 just-in-time output behavior has further improved Flash performance.

Derek also mentions that he (a Citrix engineer) found that enabling Queuing & Tossing reduced bandwidth consumption by more than 3 times. That some interesting data because I've been doing testing of my own with Flash in Citrix environments. Look for a article on the interesting results soon.

Read the entire article about Secrets for Optimizing Flash Performance Part 2.