Archive for August 2009
On my Lenovo T61 equipped with Intel PRO/wireless 3945ABG network card I have had an issue, a PITA to be more precise, for some time now. I have experienced very poor performance of the wireless networking when running Windows XP SP3, despite the fact that signal strength was “excellent” at a speed of 54 Mbit/s.
I tracked down the problem, after extensive searching on the internet, to be related to so-called “Power-save Polling”after reading an Intel note on the issue (PSP is described at TechRepublic in more detail, and also why PSP may be no good at all). The issue seems to appear when the wireless router does not properly support power-save polling. I have a Zyxel P-2602HW-D1A wireless router, and I have not been able to find any info on power-save polling for this hardware. So Intel may be correct that the router does support this feature.
In order to disable power-save polling on the Intel wireless adapter go to Control Panel -> Network Connections -> (Right click) Wireless Network Connection -> Properties and press the “Configure” button for the wireless adapter. In the “Advanced” tab choose the “Power management” property and set the slider to the highest value for maximum performance i.e. no PSP. This certainly did the trick (at least temporarily) – I could now browse the internet at full speed. However, my new found happiness was soon spoiled when I realized that the problem resurfaced after some time (actually after being in standby mode etc.). After reopening the previous configuration utillity I could also see that the power management had been reset to the lowest value (i.e. PSP on). I guessed it might be related to some kind of power save management between win XP and the Intel driver (since the issue never occured when running Ubuntu 9.04). Nevertheless, I could not find any configuration for this particular “feature” literally driving me nuts. I noticed that I had the Lenovo ThinkVantage Power Manager installed. After removing this everything worked fine, and my settings was not reset after standby. Btw. the driver for the Intel adapter is version 220.127.116.11. Updating the driver did not make any difference.