As part of the exciting VMware Horizon 6 launch, I want to share a few enhancements that have been made to our remote display protocol, PCoIP (PC-over-IP). These PCoIP enhancements will more fully optimize Horizon deployments.
PCoIP is a protocol that adapts to the available network bandwidth to provide the best user experience possible. However, in some network environments, it may be optimal to set the bandwidth usage lower, such as in a wide-area-network (WAN) environment.
As a result of collaborating closely with our customers and partners, VMware and Teradici, inventors of PCoIP, have made a few changes to the PCoIP defaults. We have also made bandwidth-management enhancements on congested and lossy networks, which will provide better performance over WAN and wireless networks.
Ultimately, what this means for end users is that they now get up to 30% bandwidth savings out of the box and a better experience on their wireless devices. The best part is that users do not have to do a thing to be able to take advantage of these improvements!
Bandwidth-Management Enhancements
The following graph illustrates the improved experience resulting from the new bandwidth-management enhancements. On a 5Mbps network with 50ms of latency, the new bandwidth-management algorithms improve frame rate by more than 20% on a 480p video and reduce the standard deviation of the frame rate by 17%. With 1% packet loss, the frame rate improves by more than 40% and reduces the standard deviation of the frame rate by 59%, thus providing a significantly improved experience.
* RTT: Round-Trip Time
PCoIP Default Changes
The following is a summary of the changes made to PCoIP defaults with Horizon 6:
- Build to Lossless (BTL) is now turned off by default
- Maximum Initial Image Quality is changed from 90 to 80 percent of lossless
- Minimum Image Quality is changed from 50 to 40 percent of lossless
Build to Lossless
With the Build-to-Lossless setting enabled, the PCoIP protocol gradually builds to a fully lossless image, providing picture-perfect clarity. This is essential for use cases such as doctors viewing medical imaging, where exact details matter. In other use cases such as typical office productivity, where a fully lossless image may not be required, disabling Build to Lossless reduces the bandwidth required by up to 20%. Even with Build to Lossless disabled, PCoIP builds to a perceptually lossless state and, in most cases, the end user cannot tell the difference. With Horizon 6, we have changed the default so that Build to Lossless is disabled out of the box. This gives users an image built to perceptually lossless, which improves bandwidth performance. If a fully lossless image is required, customers can still enable Build to Lossless.
Maximum Initial Image Quality
The Maximum Initial Image Quality setting determines the quality and compression level of the changed pixels when the screen changes for things such as pictures, animations, or videos. The prior default setting of 90 percent of lossless corresponds to a perceptually lossless level of compression. For animations and videos where the screen is constantly changing, dropping the initial image quality to 80 percent of lossless is generally not perceptible but can reduce bandwidth usage by up to 30%. (Static content is not affected by Maximum Initial Image Quality and will quickly build to fully lossless.) The result is a significant savings in bandwidth usage without any change in end-user experience.
Minimum Image Quality
The Minimum Image Quality setting determines the lowest quality and compression level of changed pixels that is allowed. This limit is reached only when the network is congested and the PCoIP session needs to conserve bandwidth. By lowering the minimum to 40 percent of lossless, the frame rates of animations and video are improved by up to 10% under constrained conditions.
The following graph demonstrates the bandwidth improvements resulting from the changes in the PCoIP defaults, measured with a LoginVSI 4 Medium workload (24% less bandwidth) and a 720p video respectively (32% less bandwidth).
New Deployments Compared to Upgrades
In the event that you upgrade from a previous View release to Horizon 6, your previous settings are preserved if you have existing Administrative Templates (ADMs). For first-time deployments of Horizon 6, the new PCoIP default values are populated, and you do not have to do anything.
In summary, VMware and Teradici are excited about the new bandwidth-management improvements and PCoIP default changes. The new algorithms and settings make View deployments ready for the WAN out of the box, and provide improved experience and valuable bandwidth savings to all types of clients, including zero, Windows, Mac, Linux, and mobile clients.
