[Jay Ts]

Soundhaspriority wrote:
This utility, DPC Latency Checker,
http://www.thesycon.de/deu/latency_check.shtml ,
graphically displays the maximum amount of time it takes for a "Deferred
Procedure Call" to execute.

Thanks, Bob!!!

It's things like this that make r.a.p. worth paying attention
to every day.

Using the DPC Latency Checker, I was able to determine what
was causing the problems on a 5 year old laptop that I'd
assumed wasn't going to be useful for audio apps.

Like practically every other laptop, the wifi adapter is a software
driven device. The WPA/TKIP security is handled in software. It is known
to be CPU intensive. The word on the street is that turning off the wifi
driver, and turning off graphics acceleration, and possibly sound card
acceleration, are the keys to reducing latency.

Friends, it is not.

Graphics and sound acceleration are no problem here, but the Wi-Fi
adapter definitely was! I was seeing a whopping 22,000 microseconds
(usec) of delays, every minute, like clockwork. That ruined it for
any serious audio application.

Disabling the Wi-Fi driver (in ... - Device Manager - Network
Adapters) fixed it.

On my laptop, the WiFi device driver was BY FAR the biggest problem.
It just varies from model to model, and the design of the device driver
for the particular WiFi adapter hardware in the system is what matters.

Maybe there are laptops with problematic graphics acceleration
and sound acceleration, too. (?)

Disabling the "Microsoft ACPI Compliant Battery Method", which is the
simple voltmeter that reports the state of charge of the battery,
reduces the maximum latency to less than 500 us with the wifi adapter
turned on.

So there we have it: In a rather generic laptop, disabling the Battery
Method in the System--Hardware tab,

That's Start - Settings - Control Panel - System - Hardware - Device
Manager - HOSTNAME - Battery

then right-click on "Microsoft ACPI-Compliant Control Method Battery",
and click on Disable. (Simple. And it got rid of the rest of
my latency issues. DPC now reports 130 usec latency with the audio
running. This old laptop is useful for audio after all!

Jay Ts
--
To contact me, use this web page:
http://www.jayts.com/contact.php

[Mike Rivers]

Jay Ts wrote:

Disabling the "Microsoft ACPI Compliant Battery Method", which is the
simple voltmeter that reports the state of charge of the battery,
reduces the maximum latency to less than 500 us with the wifi adapter
turned on.

That's Start - Settings - Control Panel - System - Hardware - Device
Manager - HOSTNAME - Battery

then right-click on "Microsoft ACPI-Compliant Control Method Battery",
and click on Disable. (Simple. And it got rid of the rest of
my latency issues. DPC now reports 130 usec latency with the audio
running. This old laptop is useful for audio after all!

Computers are all different. Althought I don't have any problems
recording as many tracks as I
want on my laptop (never more than 8), I thought this might be
interesting to look at as I've
heard of several instances where battery monitoring has affected audio
performance.

DPC shows less than 100 us with the computer idling, but it jumps to
16,000 us when playing
an on-line audio stream with Winamp. Disabling the APCI battery doodad
made absolutely
no difference. But surprisingly, it didn't make the battery charge
indicator on the task bar go away
either, so I don't know what disabling this did (or didn't do).

I suspect that the measured latency is a result of the old Digigram VX
Pocket audio card that I'm
using. When I removed it and used the SoundMax built-in audio hardware,
the DPC checker shows
about 36 us with Winamp playing. And again, enabling or disabling the
battery monitor makes
no difference.

The Windows default sound device gives two options for the VX Pocket,
one that says WDM and the
other doesn't. I'd been using the one that doesn't say WDM (VX Pocket
Mixer 1) but switching to the
WDM version drops the latency down to the 2000 us range.

When I switch to the Mackie Onyx Firewire mixer card, the DPC latency is
in the 160 us range and
doesn't change noticeably whether audio is playing or not.

More unknowns, and probably never-learns.
--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[Jay Ts]

Soundhaspriority wrote:
"Jay Ts" wrote in message
g.com... [snip]

Graphics and sound acceleration are no problem here, but the Wi-Fi
adapter definitely was! I was seeing a whopping 22,000 microseconds
(usec) of delays, every minute, like clockwork. That ruined it for any
serious audio application.

Disabling the Wi-Fi driver (in ... - Device Manager - Network
Adapters) fixed it.

On my laptop, the WiFi device driver was BY FAR the biggest problem. It
just varies from model to model, and the design of the device driver
for the particular WiFi adapter hardware in the system is what matters.

What wifi device is in the machine?

It's listed in the Device Manager as "Toshiba Wireless LAN Mini PCI Card".
The driver is by "Agere Systems", version 7.62, released in June, 2002.
I think this is the final version of the driver. It's an old laptop!

Jay Ts
--
To contact me, use this web page:
http://www.jayts.com/contact.php

[Ray Thomas[_2_]]

"Soundhaspriority" wrote in message
...

"Jay Ts" wrote in message
g.com...
[snip]

Graphics and sound acceleration are no problem here, but the Wi-Fi
adapter definitely was! I was seeing a whopping 22,000 microseconds
(usec) of delays, every minute, like clockwork. That ruined it for
any serious audio application.

Disabling the Wi-Fi driver (in ... - Device Manager - Network
Adapters) fixed it.

On my laptop, the WiFi device driver was BY FAR the biggest problem.
It just varies from model to model, and the design of the device driver
for the particular WiFi adapter hardware in the system is what matters.

Maybe there are laptops with problematic graphics acceleration
and sound acceleration, too. (?)

[snip]

I have heard that there are. I was a bit too quick to draw a general
conclusion.

What wifi device is in the machine?

Bob Morein
(310) 237-6511
------------------------------------------------------------------------------------------------
Hi Bob,

I'd tried this Latency checker before (even suggested it to others on this
newsgroup if I recall correctly !) without success....my Core 2 Duo Intel
laptop was spiking up to 4000 us every 10 seconds precisely, and after
disabling and restoring all the Usual Suspects I finally disabled the
inbuilt CD/DVD drive and ..lo and behold....it dropped down to a steady
300-500 us 'green fence' and stays that way. I've never noticed any clicks
or pops that could be attributed to those regular spike peaks, so it hadn't
bothered me much...but why would a (non operating) drive cause these ? Nice
to have tracked it down though.......! Also, I notice you say "Dual core
Windows laptops have other problems. I don't have one to test with, and I
plan to avoid them for audio capture until those problems are
resolved"......can you shed any more light on this ( mine seems to work fine
with an Audiofire 8 using Reaper and Wavelab 6) ?

Ray

[Ray Thomas[_2_]]

"Soundhaspriority" wrote in message
news

"Ray Thomas" wrote in message
...

"Soundhaspriority" wrote in message
...

"Jay Ts" wrote in message
g.com...
[snip]

Graphics and sound acceleration are no problem here, but the Wi-Fi
adapter definitely was! I was seeing a whopping 22,000 microseconds
(usec) of delays, every minute, like clockwork. That ruined it for
any serious audio application.

Disabling the Wi-Fi driver (in ... - Device Manager - Network
Adapters) fixed it.

On my laptop, the WiFi device driver was BY FAR the biggest problem.
It just varies from model to model, and the design of the device driver
for the particular WiFi adapter hardware in the system is what matters.

Maybe there are laptops with problematic graphics acceleration
and sound acceleration, too. (?)

[snip]

I have heard that there are. I was a bit too quick to draw a general
conclusion.

What wifi device is in the machine?

Bob Morein
(310) 237-6511
------------------------------------------------------------------------------------------------
Hi Bob,

I'd tried this Latency checker before (even suggested it to others on
this newsgroup if I recall correctly !) without success....my Core 2 Duo
Intel laptop was spiking up to 4000 us every 10 seconds precisely, and
after disabling and restoring all the Usual Suspects I finally disabled
the inbuilt CD/DVD drive and ..lo and behold....it dropped down to a
steady 300-500 us 'green fence' and stays that way. I've never noticed
any clicks or pops that could be attributed to those regular spike peaks,
so it hadn't bothered me much...but why would a (non operating) drive
cause these ? Nice to have tracked it down though.......! Also, I
notice you say "Dual core Windows laptops have other problems. I don't
have one to test with, and I plan to avoid them for audio capture until
those problems are
resolved"......can you shed any more light on this ( mine seems to work
fine with an Audiofire 8 using Reaper and Wavelab 6) ?

Ray
Hi, Ray. My statement is based on two things:
1. observations of other forums, and my own test of two laptops. I saw
that Motunation is full of people who cannot get a Traveler to work on
state-of-the-art laptops such as yours. I got it working with one antique
laptop, while the second laptop suffered only from the sin of being too
slow for use. Neither of my antique laptops crashed, bluescreened, etc.
2. I have noticed that multiprocessor machines are quirkier than
uniprocessor machines. Code can behave differently one each. Suppose there
is a block of data that two threads can work on. In a multiprocessor
environment, a "mutex", mutual-exclusion, is used to make sure that if the
processes are hosted on different CPU, they will wait their proper turns
to work on the data. If the programmer makes a mistake in writing the
mutex, both processors can end up grabbing for the data at the same time,
or out of order. But if the same code is executed on a single processor
machine, the bug might show, because the single processor can execute only
on thread at a time anyway.

My observations are only for pre-sale. If you have something that works,
you have "run the gauntlet."

Bob Morein
(310) 237-6511
--------------------------------------------------------------------------------------------

Bob,

Yes it seems there are many flavours of dual and multicore processors out
there, and not all audio programs are equally disposed to use those cores to
maximum efficiency...Reaper does I believe, whereas Steinberg is still
moving in that direction. The following forum (incl some Motu users) topic
highlights this:

http://www.soundonsound.com/forum/sh...rue#Post681120

By the way, my latency score dropped even more significantly when I disabled
the Battery condition indicator, as you recommended, and the only
reservation could be that the power management schemes that folks fine tune
their PC's with (eg no hibernation, screen saver off, battery power
extenders, etc) may be lost into the bargain ? You might even question
whether the on-board battery has any intrinsic use to you, as most laptops
devote a lot of resources to maximizing battery life...to the possible
detriment of audio performance, and if most of your work involves being
connected to mains AC anyway...?
Here's an example:
http://forums.cnet.com/5208-6142_102...sageID=2948458
I ran my old laptop for 2 years battery-less after it failed to hold a
charge longer than 15 mins, so I simply removed it and carried on ...! Yes
my gauntlet run worked for me, although as you've shown there is always room
for improvement.
Finally, here's a very good overview of how to recognize processor
bottlenecks, RAM drought or struggling CPU's:

http://www.soundonsound.com/sos/jul0...ician_0706.htm
Ray

[Mike Rivers]

Ray Thomas wrote:
I finally disabled the
inbuilt CD/DVD drive and ..lo and behold....it dropped down to a steady
300-500 us 'green fence' and stays that way.
...but why would a (non operating) drive cause these ?

It's probably checking every ten seconds to see if there was a disk in
the drive that it
had to do something with. You probably would have had the same result if
you disabled
the auto-detect function, but that's pretty difficult to do. People will
tell you to right-click on
the CD drive in My Conmputer and select the AutoPlay tab, but that
doesn't work. You
need to make a Registry change to actually disable the check for a new
disk in the drive.

As usual, Google for "disable Winsows CD Auto Play" or something like
that and you'll
find instructions that may be correct. g


--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[John Slater]

On Fri, 30 Jan 2009 16:33:41 GMT, Mike Rivers
wrote:

Ray Thomas wrote:
I finally disabled the
inbuilt CD/DVD drive and ..lo and behold....it dropped down to a steady
300-500 us 'green fence' and stays that way.
...but why would a (non operating) drive cause these ?

It's probably checking every ten seconds to see if there was a disk in
the drive that it
had to do something with. You probably would have had the same result if
you disabled
the auto-detect function, but that's pretty difficult to do. People will
tell you to right-click on
the CD drive in My Conmputer and select the AutoPlay tab, but that
doesn't work. You
need to make a Registry change to actually disable the check for a new
disk in the drive.

As usual, Google for "disable Winsows CD Auto Play" or something like
that and you'll
find instructions that may be correct. g


Go he

http://www.moozek.com/2008/08/21/def...ing-for-audio/

Note, some of this stuff is marginally helpful these days dues to
faster machines etc however lot's of good information here.

First thing I do on a machine is disable
auto-insert-notification.
It's nothing but a PITA even on a none DAW system.

[Ray Thomas[_2_]]

"Mike Rivers" wrote in message
...
Ray Thomas wrote:
I finally disabled the inbuilt CD/DVD drive and ..lo and behold....it
dropped down to a steady 300-500 us 'green fence' and stays that way.
...but why would a (non operating) drive cause these ?

It's probably checking every ten seconds to see if there was a disk in the
drive that it
had to do something with. You probably would have had the same result if
you disabled
the auto-detect function, but that's pretty difficult to do. People will
tell you to right-click on
the CD drive in My Conmputer and select the AutoPlay tab, but that doesn't
work. You
need to make a Registry change to actually disable the check for a new
disk in the drive.

As usual, Google for "disable Winsows CD Auto Play" or something like that
and you'll
find instructions that may be correct. g

Hi Mike, I tried that (using this source, very good as it turns out:
http://www.windowsnetworking.com/kba...dowsXPPro.html
) however that only prevents the autoplay function when a disc is
inserted, not from searching for 'disc present' every 10 secs or so. Hence
disabling the drive from Device Manager remains (for me) the best and
quickest option so far....but thanks for the tip anyway !
Ray

[Mike Rivers]

Ray Thomas wrote:

Hi Mike, I tried that (using this source, very good as it turns out:
however that only prevents the autoplay function when a disc is
inserted, not from searching for 'disc present' every 10 secs or so. Hence
disabling the drive from Device Manager remains (for me) the best and
quickest option so far....but thanks for the tip anyway !

Here's how to nuke it in Windows XP:

1. Click Start, click Run, type Gpedit.msc in the Open box, and then
click OK.
2 Under Computer Configuration, expand Administrative Templates, and
then click System.
3. In the Settings pane, right-click Turn off Autoplay, and then click
Properties.
4. Click Enabled, and then select All drives in the Turn off Autoplay on
box to disable Autorun on all drives.
5. Restart the computer.


--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[Phil W]

Mike Rivers wrote:
Ray Thomas wrote:

Hi Mike, I tried that (using this source, very good as it turns out:
however that only prevents the autoplay function when a disc is
inserted, not from searching for 'disc present' every 10 secs or so.
Hence disabling the drive from Device Manager remains (for me) the
best and quickest option so far....but thanks for the tip anyway !

Here's how to nuke it in Windows XP:

1. Click Start, click Run, type Gpedit.msc in the Open box, and then
click OK.
2 Under Computer Configuration, expand Administrative Templates, and
then click System.
3. In the Settings pane, right-click Turn off Autoplay, and then click
Properties.
4. Click Enabled, and then select All drives in the Turn off Autoplay
on box to disable Autorun on all drives.
5. Restart the computer.

Note, that "GPedit.msc" (Group Policy Editor) will ONLY work in XP PRO, but
not in XP HOME!

A better choice is to download and install a powerful little tool from MS,
called "TweakUI"
http://www.microsoft.com/windowsxp/D...powertoys.mspx

Be sure to download the normal version, NOT the one for "Itanium based
systems" - unless you happen to have one. If you do, you will know it! ;-)

Another nice and useful add-on is the "Alt-Tab replacement" on the same
page. The rest is rather of little use for most users.

After installation, open TweakUI from Start-Programs-Powertoys for XP,
- click + at "My Computer"
- then + at "AutoPlay"
- then + at "Types"

to disable AutoPlay.

Anyway, TweakUI has some other nice features besides this one. Just look
around it and you´ll see, what I mean...


Phil

[Ray Thomas[_2_]]

Here's how to nuke it in Windows XP:

1. Click Start, click Run, type Gpedit.msc in the Open box, and then click
OK.
2 Under Computer Configuration, expand Administrative Templates, and then
click System.
3. In the Settings pane, right-click Turn off Autoplay, and then click
Properties.
4. Click Enabled, and then select All drives in the Turn off Autoplay on
box to disable Autorun on all drives.
5. Restart the computer.


Thanks Mike....that did the trick !
Ray

[Mike Rivers]

Phil W wrote:

Note, that "GPedit.msc" (Group Policy Editor) will ONLY work in XP PRO, but
not in XP HOME!

Too bad.

A better choice is to download and install a powerful little tool from MS,
called "TweakUI"

That's what I tried first (well, second after clicking on "take no
action" in the Properties box for every
kind of file listed) and it still didn't keep something from popping up
on many CDs or USB memory
thumb drives. I suppose that some of this is a result of not clearly
knowing the difference between
"auto play" and "auto detect" and the fact that whatever file types
Microsoft has included in the "action"
list, someone has (or will) come up with some other file that will cause
the drive to ask what it should
do. The problem is that none of those solutions (other than perhaps the
registry edit) ever tells the
removable drive simply to acknowledge that there's something to read,
and to not even look at what
is is until I tell it to.

Another nice and useful add-on is the "Alt-Tab replacement" on the same
page. The rest is rather of little use for most users.

What does that do? I don't even remember what Alt-Tab does, but I think
I may have used
it now and then.



--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)