tweak for windows 7/Vista 64 bit users experiencing high latency in dpc checker & crackle

huh, what a coincidence.  i was just yesterday instructed by ew to download this same DPC Latency checker for my crackle problem while recording/write automating my new Kore 2 (wrapped in jBridge) hardware edition inside Sonar 8.52 PE x64.  being that i got a 2.6Ghz quad with 8 gigs of RAM, i thought my days of crackling were over.  the latency checker showed no irregularities while playing notes and tweaking knobs while recording and making massive mad crackles and dropouts.  i'm guessing it has something to do with the Kore 2 x64 hardware drivers, because i got no such problems while recording/write automating the same patch in Kore 2 while using the modulation wheel on my m-audio Keystation 61es inside Sonar.  so i appreciate this tip, as maybe it will do the trick

yes 100 to 1 doesn't make difference in reallife use, but there are people with m-audio souncards and also some other brands who have weird spikes turning up. Thos spikes will be reduced which will result into less crackle/glitching.

I am still testing a lot. A lot of questions are unanswered. What does it do? Are video's now playing out of sync? etc..
Anyone who knows and really understand this function, please let me know.

Interesting...

I am trying to build my new SONAR RIG based around a DELL STUDIO 17 core I7 laptop and a M-AUDIO Profire lightbridge interface.

I've tested a STARTECH EXPRESSCARD 2 FIREWIRE ports (TI chipset) but I experienced light audio pops and crackle during plackback... problems showed up a good 8 minutes + into the project... strange. Systems resources are OUTRAGOUSLY low (I/E : efficient... Gooood...) but I am still getting that problem.

I do not know if my troubles are caused by what is being discussed here. I'll check it out and let you guys know BEFORE I go out to purchase a SIIG expresscard...

yummay


Interesting...

I am trying to build my new SONAR RIG based around a DELL STUDIO 17 core I7 laptop and a M-AUDIO Profire lightbridge interface.

I've tested a STARTECH EXPRESSCARD 2 FIREWIRE ports (TI chipset) but I experienced light audio pops and crackle during plackback... problems showed up a good 8 minutes + into the project... strange. Systems resources are OUTRAGOUSLY low (I/E : efficient... Gooood...) but I am still getting that problem.

I do not know if my troubles are caused by what is being discussed here. I'll check it out and let you guys know BEFORE I go out to purchase a SIIG expresscard...

Seen this with various Dell machines. Some work great and others have persistent high DPC latency and are subject to clicks and pops and dropouts.

brundlefly

I sure feel a whole lot better getting a solid 9us .

 
Braggart.
 
 

I was actually kinda shocked as the same system ran at around 30-40us under Vista. And this is with an essentially out of the box Win7 installation. I've only seen DPC latency in single digits on XP installs.

Finally with Win7 we have an OS that doesn't need to be baby-sat during install and setup. You can pretty much install and go for the most part. Low number of default processes and memory usage etc...

wetdentist


huh, what a coincidence.  i was just yesterday instructed by ew to download this same DPC Latency checker for my crackle problem while recording/write automating my new Kore 2 (wrapped in jBridge) hardware edition inside Sonar 8.52 PE x64.  being that i got a 2.6Ghz quad with 8 gigs of RAM, i thought my days of crackling were over.  the latency checker showed no irregularities while playing notes and tweaking knobs while recording and making massive mad crackles and dropouts.  ........

Wetdentist, since you have an m-audio card, try also to test always with only having Sonar opened (no IE,firefox,antivirus, etc). See if changing playback/record timing master makes any difference.
 Sonar > Options > Audio > 'general tab', change playback timing master to another input and change record timing master. 

Phoenix

Brandon Ryan [Cakewalk
]

yummay


Interesting...

I am trying to build my new SONAR RIG based around a DELL STUDIO 17 core I7 laptop and a M-AUDIO Profire lightbridge interface.

I've tested a STARTECH EXPRESSCARD 2 FIREWIRE ports (TI chipset) but I experienced light audio pops and crackle during plackback... problems showed up a good 8 minutes + into the project... strange. Systems resources are OUTRAGOUSLY low (I/E : efficient... Gooood...) but I am still getting that problem.

I do not know if my troubles are caused by what is being discussed here. I'll check it out and let you guys know BEFORE I go out to purchase a SIIG expresscard...

Seen this with various Dell machines. Some work great and others have persistent high DPC latency and are subject to clicks and pops and dropouts.

How do you tell which are the good ones?

I wish I knew - I really do.

brundlefly

I was actually kinda shocked as the same system ran at around 30-40us under Vista. And this is with an essentially out of the box Win7 installation. I've only seen DPC latency in single digits on XP installs.

 
My system (OEM Dell Q9550) used to idle in that same 30-40us range with XP x86. Now under Win7 x64, it's often over 100us, but this hasn't had any measureable effect on my audio performance under high loads with 2ms buffer (the lowest my 1820m will go).
 
 

Yup I've seen similar behavior on some machines of DPC latency actually going up on Win7 (even from Vista). I suspect drivers in this case and specifically LAN and/or video card drivers.

But as you said, 100us is really quite low in the overall scheme of things and it's DPC spikes that really concern me.

thomasabarnes


JohnCR:

I wonder what Brandon's Mobo, Memory, and CPU is which get's him a solid 9us. Wow!

MB is an Intel DX58SO
Memory is made by Mushkin (triple channel mode)
CPU is an i7 965 (3.2)
Video Card is an Nvidia GS7600 (512mb)

other random notes:
Audio device is V-Studio 700R
LAN is enabled
using Win7 Professional x64
1x UAD1 PCI & 1x UAD1 PCIe
Hard Drives are Intel X25 SSD's.

I think that's it.

I've really yet to encounter a project where I have to raise the latency above 2.2ms. No crackles and no pops.

Another cool thing: I was actualy able to turn my I/O buffer sizes down to 64 (I have always used 128 in the past) and now playback and stopping feels instantaneous even on large projects. Yay! This could be due to the SSD though.

I was actually kinda shocked as the same system ran at around 30-40us under Vista. And this is with an essentially out of the box Win7 installation. I've only seen DPC latency in single digits on XP installs.

 
That's about as low as you can get DPC latency in Vista SP2
In Win7, you can achieve a steady 7-9uSec
Win7 (straight out of the gate) is going to be a great DAW platform.  We're set for the next 5+ years.
 
If you're not working at ASIO buffer sizes of 64-samples or smaller, then DPC latency below 100uSec isn't really all that important.
If you're wanting to push the machine hard at low latency settings (especially with high sample rates), then having extremely low/steady DPC latency is a great benefit.  At 7-9uSec, it's effectively a non-issue.
 

Ok... little update on my side...

Still trying to configure a DELL STUDIO 17 core I7 Laptop. (2 dedicated hard drives, 4 gigs of RAM, Win 7 Pro.) Still no luck... My FIREWIRE PROFIRE LIGHTBRIDGE still produces light pops. and crackles...

tried 2 different EXPRESS CARD 34 for firewire connections (TI chipset) A STARTECH and a SIIG... same problems

Brandon, you are scaring me! When you say that DELL machines have persistent DPC issues, are you sayig these cannot be corrected?


The strange thing is: the more I am tweaking WINDOWS 7 (as recommended on forums like Cake's, M-Audio's and Digidesign),  the more my pops and crackles are getting louder and more frequent...

I'll now try to disable the HPET (High Precision Event Timer) in the BIOS, but my laptop's BIOS seems to have a couple of settings lock down by DELL... I'll try this tonight and I'll also try to understand if the problem could be related to IRQs (the express cards and firewire audio device always get IRQ 16 assigned to them... I have only 1 slot, so using only 1 card at a time, of course...)

I do not fully understand yet which ressources might be shared / be conflicting between the EXPRESSCARD channel and the other USB / ESATA ports... I'll also have a look at LAN and video card drivers (but with so much ppower available in this laptop, how could this be a real problem??)
 
I'll be sharing my little results. I just hope they will be usefull (and that my DELL will finally work...)

Will do!

Thanks for the heads up.

brundlefly

I was actually kinda shocked as the same system ran at around 30-40us under Vista. And this is with an essentially out of the box Win7 installation. I've only seen DPC latency in single digits on XP installs.

 
My system (OEM Dell Q9550) used to idle in that same 30-40us range with XP x86. Now under Win7 x64, it's often over 100us, but this hasn't had any measureable effect on my audio performance under high loads with 2ms buffer (the lowest my 1820m will go).
 
 

brundlefly,
What driver did you use to get the 1820M to work with Win7 64bit?
We must have a Win7 version difference preventing me from using XP driver, if that's the driver that worked for you.
 

brundlefly, What driver did you use to get the 1820M to work with Win7 64bit? We must have a Win7 version difference preventing me from using XP driver, if that's the driver that worked for you.

The v2.1 PatchMix/Driver update included support for Vista x64, and (mostly) works in Win7 x64. I have an occasional BSOD caused by a Creative/E-MU .SYS module, but it's relatively rare, so I'm living with it until E-MU delivers a dedicated Win7 driver. I think they will, eventually, because all of the PatchMIx-based cards they're still producing use this same driver. But they were slow to deliver the Vista driver so I'm not holding my breath.

I also have a problem reported in another thread that the I/O channels are not presented to SONAR with the same naming they had under XP, which means all of my existing projects have trouble with I/O assignments. This is actually causing me way more headaches than the BSODs. I haven't been able to nail down whether this is an x64 issue (either in the O/S or in SONAR) or a Win7 thing.


EDIT: Here's my thread on this, in case you want to continue the discussion there:

http://forum.cakewalk.com/tm.aspx?m=1917189

I was a little surprised I didn't get more responses from 1820m users, as I know there are a fair number of them on the forum. But maybe they did better research than I did, and have put off the move to Win7 x64. 

yummay

about M series workstation lap

 
Darn! Looks that i'm in big trouble right now... I just hope the STUDIO 17 form Dell are made differently than the M series laptop...
 
I hope that i'll be able to sort this out...

Well if it makes you feel any better we are all here to help you in any way we can. Collectively there's some great knowledge at hand.