Vista - Device Driver Polling every 30ms ... can it be Turned OFF ?

[benifin]

Hi nuhi

Firstly, keep up the great work ... you are a legend !!!!!

Now .......Vista great ....... EXCEPT ....... for low latency audio use.

The key culprit here is the Device Driver Polling whereby device drivers are required to poll the underlying hardware every 30ms for digital outputs and every 150 ms for analog ones to ensure that everything is OK.

This Device Driver Polling causes MASSIVE problems and havoc [ ie: audio crackling, audio pops, audio glitchs etc .... ] when you are recording / playing back audio at virtual-real-time-latencies ie: 1.5ms or lower because even with nothing else happening in the system, a mass of assorted drivers have to wake up thirty times a second just to ensure that **nothing** continues to happen.

Anyway ...... above speil aside nuhi ...... is it possible for you to make this Device Driver Polling *feature* "turn-off-able / turn-on-able" with VLite ?

Thanks,

Ben

[nuhi]

Thank you for the compliment.

Are you sure that this is something you want to disable, I would like it to check if "everything is ok"?

But if you're actually implying on that DRM pooling for protected content then I agree.

Now if it's legal to disable that (highly unlikely) and even possible to find and disable I'll gladly do it.

Try to remove WMP with the codecs, that might help since it's directly connected to DRM. But wait for the next version few days, it has even more components which removal may secondary lower latency.

[benifin]

Hi nuhi

This is DEFINETLY something I would like to disable.

I cant possibily see or imagine that this would in any way be illegal - no diffent to removing WMP or IE7 or disabling the Destop cleaner etc......

My VLite has no WMP at all and no audio or video codecs other than my pro-studio sound card and the 30ms Device Driver Polling is still there

Cant wait for the next version !!!!! Only a " ..... few days .... " away !!!!!!! Woooooooooo Hoooooooooo

If the Device Driver polling can be "disabled / abled" at user discretion in the next or upcoming version, then words would not describe the achievment / benefit to all semi-pro / pro-audio users everywhere !!!

Keep up the fantastic work nuhi -

Thanks again,

Ben

[nuhi]

I appreciate the enthusiasm but unless we know which service or setting that exactly is there is no hope for the resolution

How did you even saw that polling to be sure in it?

[pallavsuri]

@nuhi

looking forward to the new version! hopefully before the end of the month! as ive got university papers in may

@ben

about this polling issue. latencies are in us per ms units not just ms! and every OS does it in 30ms or so. you probably want a longer time gap say 1 sec? is that possible? its like telling your heart to beat 30 times a minute rather than usual 72.

meaning you probably want the us to come down. that is the number of processes pending at the processer at every cycle. thats around 1000 us in vista and 80 us in XP.

bringing down us(work pending with processor related to the OS) to near XP levels would be the goal, i would guess. correct me if im wrong!

[Jeronimo]

Not sure if there would be any gain taken from it. Polling might not give anoticeable dealy (if you know how the principle works). Only if there is an actual task waiting, when polled, then there will be a delay. Would it matter if a device is attached and appropriate action is taken after 1 second instead of 30us? I do not think so and if it would really matter, then I will think that Microsoft would have set the polling time lower per default. Because if this would cause noticeable decrease in performance, they would not set it up like this.

[benifin]

Hi nuhi & pallavsuri & Jeronimo

The following (2) links may provide a more specific “in-road” into how to address this Device Driver polling issue

Firstly:- http://geekswithblogs.net/sdorman/archive/...6/17/82189.aspx

Secondly:- http://www.microsoft.com/whdc/system/CEC/mm-timer.mspx

Again, thanks again for all your work !!!

Ben