Troubleshooting Graphics Performance; Configuring Your Network For Optimal Performance - HP Xw460c - ProLiant - Blade Workstation User Manual

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11-3 Troubleshooting graphics performance

The dominant factor impacting performance on the Sender is the frame buffer read performance of the graphics
adapter. Frame buffer read performance of at least ten frames per second is recommended for optimum RGS
performance.
RGS uses the Remote Computer graphics adapter to accelerate rendering of the image. After the image on the
Remote Computer is modified, the RGS Sender reads the rendered image from the frame buffer, compresses it,
and transmits it to the Receiver.
On Windows, use BltTest to test the frame buffer read performance of the Remote Computer. This tool is available
at www.stereopsis.com/blttest/

11-4 Configuring your network for optimal performance

RGS depends on low network latency and reasonably high network bandwidth. There are several methods to test
and measure the network bandwidth, latency, and the number of hops between Sender and Receiver computers:
Use the ping command to measure network latency. From a command prompt on Windows or a terminal
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window on Linux, execute ping hostname. This will report the network latency. Be sure the ping protocol
(ICMP) is not blocked by a firewall. Windows may be set up with IPSec filters—be sure there is no IPSec
filter policy disabling ICMP traffic.
Use Traceroute (Linux) or tracert (Windows) to measure the network latency between two computers.
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Traceroute will report the number of hops it takes to reach a computer in addition to the network latency.
Use ttcp to measure the network bandwidth. ttcp is available at:
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www.pcausa.com/Utilities/pcattcp.htm
Once you've characterized your network performance, you can decide if improvement is required. Several
possible steps are described below.
The computer NIC will auto-negotiate the network speed with the network switches on the local network. The
negotiated speed can vary from 10 Mb/sec half duplex to 10 Gb/sec full duplex. Most modern NICs and
switches will negotiate the highest possible speed available. However, unless the network has been carefully
designed for maximum throughput, the NICs and switches may auto-negotiate to a sub-optimal speed.
If the NIC and switches are configured to auto-negotiate properly, you can leave the settings to auto-negotiate. If
you want to force the network to operate at a particular speed, the settings in the NIC and switches can be hard-
coded. You must be careful with these settings, however. If the NIC and switch settings don't complement each
other, the network will have poor performance.
Configuring the NIC on Windows—You can change the link speed and duplex mode on Windows by
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opening the Device Manager. Click Control Panel>System>Hardware Tab>Device Manager. Once the
Device Manager is open, click the + next to Network adapters. Then, right-click on the network adapter that
you want to change, and select Properties. Click the Advanced tab. Each network adapter has its own
properties/settings that can be changed. The property that affects the link speed and duplex is usually
named "Link Speed & Duplex". Click that property. If you want auto-negotiation, select the Auto Detect
entry in the Value box. If you want to hard-code the speed and duplex, always choose the fastest link your
network can support, and always choose full duplex.
Configuring the NIC on Linux—On Linux systems, the ethtool tool can be used to configure networking.
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Perform the following steps to obtain and set the network characteristics on Linux. To obtain the LAN
characteristics for interface 0, as root, type:
$ /usr/local/sbin/ethtool eth0
To set the LAN characteristics for a 100 Mb/sec connection running full-duplex mode, as root, type:
$ /usr/local/sbin/ethtool -s eth0
If you are not satisfied with your network performance, look at the log files on your network switch (if the Local
Computer is connected to one). A significant number of errors on the switch port may indicate that the computer
speed 100 duplex full autoneg off
Optimizing RGS performance 177