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ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

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ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Sat Jun 23, 2018 10:57 pm

Hi,

New i7 8th generation 16gig Dell inspiron laptop arrived this month.

Clicks using an audio in DAW (repear) making it unusable.

Latencymon identifiying ACPI.sys as cuprit.

Done all the usual:
disabled in device manager ACPI bettery control, wifi and LAN etc etc
turned off anti-virus
Full power mangement
background processes priority
and all the others ever recommended.

I'll have to send it back I think - some laptops just can't be sorted in this respect??

THanks!

Gav
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby ef37a » Sun Jun 24, 2018 6:26 am

I see that ACPI.sys is also part of 'Plug and Play'. I wonder if disabling PnP in Services would help?

Naturally you would have to do that AFTER you have plugged and played!

Dave.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby blinddrew » Sun Jun 24, 2018 8:55 am

Hi banterbanter,
Sorry, i'm struggling a bit with the brevity of your post ;) ...
Are you saying you're getting clicks and pops on the audio when recording in Reaper? Or that the latency is making a click track unusable?
There could be different causes for each one.
What's the rest of your set up like?
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby ef37a » Sun Jun 24, 2018 9:07 am

blinddrew wrote:Hi banterbanter,
Sorry, i'm struggling a bit with the brevity of your post ;) ...
Are you saying you're getting clicks and pops on the audio when recording in Reaper? Or that the latency is making a click track unusable?
There could be different causes for each one.
What's the rest of your set up like?

Quite Drew. We don't even know the AI? Could be something I cannot condemn
by name for possible LEGAL implications! (but we ALL knows who you is!)

Cannot see how a lappy of that power can be a bother when this i3 HP laptop with 8G ram* runs 20 tracks of Cubase faultlessly (imported) It also runs The Sam ProX3 demo and some SoS downloads. (should have said. Either through the OBS and cans or a KA6.)

*Oh! I am really ga-ga this morning. Was also fine when it only had 4G ram.

Dave.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby Wonks » Sun Jun 24, 2018 9:10 am

Have you tried fixing the power management setup for the laptop so that everything is at maximum? If the OS is spending a lot of time checking to see if it needs to reduce or increase power to processors, drives etc. then that's all time not being spent on your audio projects. With a fixed power management profile that doesn't require things to slow down, then the software shouldn't spend time monitoring those items.

If the laptop is dual purpose, then you may want to swap between two power management settings for general and recording use.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Sun Jun 24, 2018 10:22 am

Thanks for the replies folks!

Click during audio playback even with a simple few tracks running a few VSTi's in reaper either with internal sound card using ASIO4all or my focusrite 6i6 2nd generation sound card.

CPU running at just 20%.

Yes - power management set up correctly full 100% processor all the time.

This is a specific problem with ACPI and some laptops..

There is not a tweak I have not tried, to my knowledge. I will look at your suggestion thanks Dave.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby blinddrew » Sun Jun 24, 2018 10:38 am

One issue I've had previously is that my laptop and interface are both Class II devices so they run off wall warts and don't have an earth. Depending on what else you're plugging into the interface this could mean your whole system is unearthed, which can result in pops and clicks.
I solved this in my set-up by making up one of these: https://www.soundonsound.com/reviews/gr ... ction-plug [EDIT] they're cheap to buy but DO require a bit of home soldering. Or make your own if you have the bits lying around.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby Pete Kaine » Mon Jun 25, 2018 8:45 am

It seems these days that this is one of the most common and certainly one of the hardest to solve problems when it comes to DPC complaints. Yes, ACPI.sys is related to plug and play, but it's also everything power related and with the laptop that includes the battery charging circuit and related monitoring routines.

Sometimes if you test this with and without a mains connection, one of those states might work better than the other. But the is is no magic bullet here and you sound like you've done all the obvious stuff.

Send it back if you can, I would in that situation.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Mon Jun 25, 2018 5:54 pm

Thanks Pete

I agree with you and am sending it back..

Pondering getting a Mac for the first time ever. I'm getting too old for this nonsense.

This Dell was only £640 for 8th gen i7, 16 gig ram and 500gig SSD + 15.6" 1080p touchscreen.
The Mac equivalent would be £1500.. :(

You know of any PC's manufacturers that are DPC issue free?

Thanks

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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby James Perrett » Mon Jun 25, 2018 7:00 pm

banterbanter wrote:You know of any PC's manufacturers that are DPC issue free?

I'm using a refurbished Dell Precision M4600 which seems to be working OK with my new Zoom U44 interface although I've not tried it at really low latencies yet (I'm using the 512 sample default setting). It is only a 2nd generation i7 although the next generation 4700 and 4800 seem very similar.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby CS70 » Mon Jun 25, 2018 8:49 pm

Just to make sure - if you look at the events log, do you see any errors?

ACPI requires collaboration of all drivers which have some sort of power management so a buggy driver can create issues with ACPI resulting in high DCP count.

The most common symptom of that is that the system behaves well when starting, but start exhibiting high DPC values when returning from standby or after some use.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Tue Jun 26, 2018 1:36 am

Hi

I used snappy driver - all my drivers are the latest as is the bios.

Thanks
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby CS70 » Tue Jun 26, 2018 6:31 am

banterbanter wrote:Hi

I used snappy driver - all my drivers are the latest as is the bios.

Thanks

Well, latest doesn't mean necessarily bugless ;-)

If you look at events (using "Event Viewer") and you find a device is reporting errors, you can either disable the device or see if a different configuration helps the driver behave. There can also be other issues. Worth knowing instead of assuming.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby Pete Kaine » Tue Jun 26, 2018 9:20 am

banterbanter wrote:This Dell was only £640 for 8th gen i7, 16 gig ram and 500gig SSD + 15.6" 1080p touchscreen.
The Mac equivalent would be £1500.. :(

You know of any PC's manufacturers that are DPC issue free?

Oddly enough, yes :lol:

But, I'm first to admit we're probably not far off the MacBook prices when it sounds like you just want an off the peg rather than custom. The answer is no, it's luck of the draw from generation to generation.

The problem for audio users is that the official MS guidance for DPC handling is 1000us is permitted for any given driver process running under windows. For our purposes, a total of 1000us across all the drivers is enough to tip the audio handling into the pit of glitchy doom. So if you have 10+ drivers all running around 100us, then your sunk.

The only way to ensure no issues is to allow for it as the configuration is developed and I do get the impression a lot of firms do try and keep it at least under consideration during the design phase these days. That said, trying to hit a price point might restrict the available options along the way or what we tend to see with laptops is combination controllers that handle multiple processes being used, and sometimes a driver update later in the product cycle might end up scuppering it.

Laptops tend to cycle models very quickly, and this means that often by the time a batch is checked and qualified, the shop will already be getting notifications about the next model upgrade that's on its way. It means I've seen good working models from most of the firms out there, but I couldn't comment on what's going to work right now, as models will have changed or even just taken on revisions that might have moved the goalposts.

If you want to try and pick something up, all I can really say is try and find somewhere with units on display and would be willing to test DPC on the shop floor for you. It might be an interesting conversation admittedly!
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Tue Jun 26, 2018 8:31 pm

Thanks Pete and everyone,

Dell are collecting it tomorrow and I'm going to try this instead:

https://www.amazon.co.uk/ASUS-VivoBook- ... op?ie=UTF8

At least it's easy to send stuff back with Amazon :)

This time I'm not going to spend 3 days loading all my VSTi samples before checking DPC latency haha.

If I want to upgrade this one to 16gigs of RAM - can I just buy a matched in spec 8gig card off crucial or do I have to buy a 'matched pair'? - just trying to save some money!

Thanks again,

Gavin
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Tue Jun 26, 2018 8:39 pm

CS70 wrote:
banterbanter wrote:Hi

I used snappy driver - all my drivers are the latest as is the bios.

Thanks

Well, latest doesn't mean necessarily bugless ;-)

If you look at events (using "Event Viewer") and you find a device is reporting errors, you can either disable the device or see if a different configuration helps the driver behave. There can also be other issues. Worth knowing instead of assuming.

Thanks,

It's only the ACPI.sys driver that's causing my issue and it doesn't go away when disabling the ACPI battery management in device manager. As someone else has already said - ACPI is a nightmare with laptops and it's hit or miss. This time it's a miss.

Here's hoping my ASUS does better.

Will report back asap, as I'm sure most of you can hardly sleep with concern for my predicament.

Gav
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby CS70 » Tue Jun 26, 2018 11:11 pm

banterbanter wrote:It's only the ACPI.sys driver that's causing my issue and it doesn't go away when disabling the ACPI battery management in device manager. As someone else has already said - ACPI is a nightmare with laptops and it's hit or miss. This time it's a miss.

Here's hoping my ASUS does better.

Will report back asap, as I'm sure most of you can hardly sleep with concern for my predicament.

Eyes wide open. :D

Just to make sure: you are saying you have actually opened the event viewer and found zero errors there, right?

Because ACPI.sys may show high DPC latency (reported for example by xperf or GUIs like latencymon) due to something else.
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Tue Jun 26, 2018 11:39 pm

Pete Kaine wrote:
banterbanter wrote:This Dell was only £640 for 8th gen i7, 16 gig ram and 500gig SSD + 15.6" 1080p touchscreen.
The Mac equivalent would be £1500.. :(

You know of any PC's manufacturers that are DPC issue free?

Oddly enough, yes :lol:

But, I'm first to admit we're probably not far off the MacBook prices when it sounds like you just want an off the peg rather than custom. The answer is no, it's luck of the draw from generation to generation.

The problem for audio users is that the official MS guidance for DPC handling is 1000us is permitted for any given driver process running under windows. For our purposes, a total of 1000us across all the drivers is enough to tip the audio handling into the pit of glitchy doom. So if you have 10+ drivers all running around 100us, then your sunk.

The only way to ensure no issues is to allow for it as the configuration is developed and I do get the impression a lot of firms do try and keep it at least under consideration during the design phase these days. That said, trying to hit a price point might restrict the available options along the way or what we tend to see with laptops is combination controllers that handle multiple processes being used, and sometimes a driver update later in the product cycle might end up scuppering it.

Laptops tend to cycle models very quickly, and this means that often by the time a batch is checked and qualified, the shop will already be getting notifications about the next model upgrade that's on its way. It means I've seen good working models from most of the firms out there, but I couldn't comment on what's going to work right now, as models will have changed or even just taken on revisions that might have moved the goalposts.

If you want to try and pick something up, all I can really say is try and find somewhere with units on display and would be willing to test DPC on the shop floor for you. It might be an interesting conversation admittedly!


Ha ha! I've just realised you are Mr Scan :)

Yes, I was looking at your site and your laptops look good:

https://www.scan.co.uk/3xs/custom/daw-d ... actors#anc

- and prices are good value I'd say. I just wanted something smaller and lighter - hence my rolling of the dice with the ASUS - no doubt I'll be back to buy a Scan in a week or two :)

Can you put the six core i7 in the 15" laptop?

Thanks!
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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby banterbanter » Tue Jun 26, 2018 11:42 pm

CS70 wrote:
banterbanter wrote:It's only the ACPI.sys driver that's causing my issue and it doesn't go away when disabling the ACPI battery management in device manager. As someone else has already said - ACPI is a nightmare with laptops and it's hit or miss. This time it's a miss.

Here's hoping my ASUS does better.

Will report back asap, as I'm sure most of you can hardly sleep with concern for my predicament.

Eyes wide open. :D

Just to make sure: you are saying you have actually opened the event viewer and found zero errors there, right?

Because ACPI.sys may show high DPC latency (reported for example by xperf or GUIs like latencymon) due to something else.


Yes I did :)
But, after spending about 10 hours trying everything any site / forum suggested to no avail, life is too short. And I can't at this point now remember what the event viewer said haha.

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Re: ACPI.sys DPC latency on new Dell laptop - please help. I am depressed.

Postby CS70 » Wed Jun 27, 2018 11:16 am

banterbanter wrote:Yes I did :)
But, after spending about 10 hours trying everything any site / forum suggested to no avail, life is too short. And I can't at this point now remember what the event viewer said haha.

Gav

Too short indeed. There can certainly be buggy BIOS firmware tables but ACPI can get a lot of flak for badly written functional drivers.

Best of luck with the new one!
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