Wolfenstein: Enemy Territory – Tips & More


PS/2 vs. USB: Optimize your mouse-/USB-polling-rate for smoother aiming
Wednesday, November 26, 2008, 1:45
Filed under: Config | Tags: , , , , , , , , ,

When your mouse pointer flickers or doesn’t run smoothly, maybe the refresh rate of your mouse it set too low…

What’s the mouserate?

To be able to move your mouse cursor on screen of course your operating system has got to know the mouse has been moved by you on the mouse-pad. This is done by polling the mouse for any input at the device it is plugged in. Basically you can use the standard PS/2– or an USB-port to plug in your mouse. PS/2 comes with a standard polling rate of 80hz (adjustable from 20 hz to 200 hz). USB comes up with a standard polling rate of 125hz (overclockable to 250hz, 500hz and 1000hz). Depending on your setup, you force your mouse to send data via PS/2 or USB to your operating system every 8 ms (= 125hz), 4 ms (= 250hz), 2 ms (= 500hz) and so on…

What’s the positive effect of a higher mouserate?

Your cross-hair may move more smoothly the higher the polling rate is set up. You will feel the difference from 125hz to 500hz. But you probably won’t feel any more difference between 500hz and 1000hz. A smooth mousemovement is essential in Wolfenstein: Enemy Territory, as you need to be able to aim precisely, you need to be able to target fast and you got to avoid any erratic movements. Sometimes it is just the little 1 ms of reaction time that is missing due to imperfect hardware setup and that thus makes you lose a duel. So you should set it up to 200 hz (PS/2) or 500hz (USB) if you don’t witness any of the possible disadvantages (USB) – like I do ;-)…

Any risks of a tweaking the USB-polling-rate?

Yes – there may be some! First: the higher the USB-polling rate, the higher your cpu-usage will be. Depending on your hardware this increase can be massive for each usb-device that is excessively refreshing data at high frequency. Further more common risks in combination with overclocking your USB-polling rate are damages to your hardware (e. g. your mainboard or your usb-peripherals such as your mouse if it can’t handle the higher polling rate) or stability issues with your pc. Tweak on your own risk!

How do I raise the polling rates?

PS/2 settings from RaZiel

PS/2 settings from RaZiel

To tweak your USB-ports use UsbRate v0.5 from RaZiel (download). Make sure you disable the realtime feature as it may crash your pc.

To tweak your PS/2-port go into your mouse-properties menu or use the PS2Rate-Tool (download) and adjust it like the thumbnail shows.

Reboot to let the changes take effect.

How do I test the changes?

Use mouserate.exe from Oliver Tscherwitschke (download) to measure your actual polling rate. To do this, move your mouse around in circles and watch the output. Ideally the measures are constant or at least not changing massively each poll. This would eventually damage your mouse and besides it would not support a smooth aiming.

So… in the end?

Don’t expect to be able to boost your aiming skills by adjusting the polling rate. But this is just one of many stones in the mosaic you can use for little improvement. I personally use a Logitech MX 518 mouse via the PS/2 port. The samplingrate is set up to 200hz with input buffer length 100. RaZiel suggested an input buffer length of 300 (see thumbnail from Aiming By RaZiel-Tutorial). I tried out USB at 500hz once but it ate just too many of my cpu-resources plus it seemed I did not to get a stable polling rate, so I got back to PS/2 again with which I played for many years… and it still works fine for me. 🙂

Poll:



3 Comments so far
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fail siteul demult nu am mai ras asa

Comment by Bogdan

Do you agree with my statement that this post is awesome? gaeaeddecdef

Comment by Johne371

When I D/L’d this program and read the readme file it said it was for Win 9x, no mention of any NT OS. I have Win 10, so it’s likely to cause problems. PLEASE update this progs info to state if safe for Win 7-8-10… soooooon!

Comment by jopower




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