XPS 15-9570, Windows 10, high DPC latency, acpi.sys

Hello !
(This is a Google translation
I bought 15 days ago an Inspiron 14-5482 Win 10, I7-8565U, 16 RAM, SSD 512 GB for music production.
Big disappointment when I tested the laptop with LatencyMon !! More than 4 sec latency, while I had disabled all Windows Apps.
* After 10 days of fighting with the parameters of the Inspiron, it works very well in Studio One 4.5 (in this version they have improved the multi-core management a lot), no crunch and the processor is very quiet in the bar of SO1.
If it can help here what I did, but beware this PC only serves me for music (no web, no games, ....).

- I installed the DELL updates + installation Bios 2.5 (I saw a SpeedShift parameter that I did not notice in the 2.4, it may have helped a little.)

- I followed the Presonus configuration tips:
https://support.presonus.com/hc/en-us/articles/360025279231-Optimizing-Your-Computer-for-Audio-Windows-10

- Follow the advice of "Psychlist1972" from microsoft, update KB4505903 OS build 18362.267 (I don't know if really helped):
https://www.gearslutz.com/board/music-computers/1266677-huge-latency-issues-latest-1903-windows-release-solved-10.html

- Then uninstalled McAfee demo, MS office and all that stuff ... Disabled automatic updates of all, Dell, windows 10 (PC not connected to the web) we'll see later. Uninstall the NVIDIA driver, disable WIFI + Ethernet, disable all unnecessary windows functions, disable everything in Windows Defender.

Finally, in "msconfig.exe", tried minimal boot and disabled all non-windows background services. Here the audio peaks in Lantencymon had disappeared !! Finally, I only disabled 4 or 5 services + all Dell support services. Of course, disabled apps at windows startup.
https://support.microsoft.com/fr-ch/help/929135/how-to-perform-a-clean-boot-in-windows
The inspiron works well, playing music and video on windows media player.

Good luck and good music.

I forgot. I use an old Edirol Ua-25ex sound card, with its recent win 10 driver.

I have a Dell 7577 laptop and was plagued by the ACPI.sys issue. I have have made massive improvements by doing the following.

The latency issue affects playback because it is disruptive. I tried so many things with it.

-Replaced the wifi card

-Process lasso to dedicate cores unused by ACPI.sys to my daw.

-update to latest BIOS that is supposed to fix this. 

-Disable wifi, antivirus, optimization of windows etc.

I used to no be able to play more than 1 minute of playback with 4 tracks of audio and a couple midi tracks without disrupting the audio signal. I got better, now I have 5 mins...

When producing music or song writing, the last thing I have time for is to tweak my computer...

I will never touch a DELL again for music production or performance machine. I am still paying for it and i would have a hard time passing the problem to someone else. I am using it for basic software development and will keep it like this until I recycle it.

Cheers,

A never again DELL 20 years loyal customer.

I'm about to buy a Dell XPS and start using FL studio to make some tunes.

I'd like to connect a USB keyboard, like AKAI MPK mini and maybe an electric guitar. Will these be unusable? 

Does this latency issue mean that once I press a note on the keyboard, there's a delay in response in the software? Or is this something related to live performances? I don't fully understand how it works and would appreciate if someone could update on possible solutions since it's been a while since the last comment... 

That is really sad to hear... So even if I use an external audio interface, such as Focusrite Scarlett, and plug the USB keyboard there, this still won't reduce latency? 

Dell 9570 owner. Surfing the net I’ve finally found a solution for ACPI.sys causing high DPC latency. If you simply disable ACPI battery controls from device manager, ACPI.sys will continue to degrade your performance due to the installed temperature control devices. You need to permanently disable the Intel DPTF (power throttling) and ACPI.sys will disappear from your latencymon with a dramatic decrease of latency and you’ll be happy watching your red bars disappear.

BE CAREFUL using this trick because disabling thermal control can cause an hotter CPU. Naturally temperature limit is still present and computer will suddently shut down if critical temperatures are reached (97° I suppose).

Personally I’ve repasted my CPU and also with DPTF disabled my temperatures hardly raises the 60° (about 48-50 doing light activity or DJing with traktor) but I’m also sure that hotter CPU will shorten this notebook life.

I’ve a multiboot system and I use a partion for a music oriented Windows 10 operating system with this mods applied and a “normal” Windows 10 for daily activities.

In order to disable Intel DPTF, in Device Manager find in “System Devices” all the devices starting with “Intel(R) Dynamic Platform and Thermal Framework”. Right click on each and “Uninstall device”. Check “Delete the driver software for this device” whenever available.

Now Disable the ACPI batteries from Device Manager and enjoy your lower DPC latency (you deserve it from a 1700euros notebook).

PROBLEM: Windows sistematically reinstall DPTF drivers. If you want to prevent Windows from automatically reinstalling DPTF you need to add some Registry Keys that tells to not reinstall specific drivers (now labeled “unknown devices in Device Manager). Here’s a reg.file that do it: https://bradshacks.com/disable-dptf/

In order to revert to original configuration (and enable DPTF again), simply delete HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\DeviceInstall\Restrictions and restart windows.

PS Disabling wi-fi and other peripherals not music related is still valid. Add the DPTF and ACPI Disabling and your notebook will be DAW ready.

PPS Sorry for my really bad english.

BE CAREFUL using this trick because disabling thermal control can cause an hotter CPU. Naturally temperature limit is still present and computer will suddently shut down if critical temperatures are reached (97° I suppose).

Interesting find

I'd mention that removing Intel DPTF was once a popular thing to do for reducing throttling among gamers. However it was never perfectly clear what thermal protections were implemented with DPTF and what by other means (clearly direct CPU and GPU throttling are local, but other forms of throttling independent from DPTF were presumed, and DPTF was guessed to be malfunctioning on some laptops...). 

In any case, XPS 15, due to inadequate cooling for the hi-spec chips, vitally relies on thermal throttling, and removing the latter may help get it fried. So I wouldn't recommend anyone to remove it before making sure the thermals are basically okay (I mean good paste, clean vents), and also doing something about VRM heat. It is well known that the XPS 15 VRM area (voltage regulator mosfets in the centre-top part of the mobo) has practically no cooling (no heat-spreader, no airflow) and that it tends to overheat under prolonged loads (look up XPS 15 9560 thermal insanity FLIR images/video). Removing DPTF presumably removes thermal protection for this area from certain "Ambient" sensor(s). So before removing DPTF, at least consider padding the VRMs. There are several variants floating around because these are different simple tricks to improve things a little bit, while even much more elaborate methods were not able to stop throttling from kicking in entirely. 

I have basically the same ACPI-issue with a Precicion M2800 on W7.

BUT: only after the first boot on a day. Means: If I restart the system, the problem disapears for the whole day (also on repeated restarts). If I switch off the laptop overnight, on the next morning latency (and ISR and DPC count in LatencyMon) is extremely high again ... until I restart. If I put on standby overnight no problem the next day, if I put on hibernation overnight, latency is high again after start on the next day. So obviously the first hardware boot a day triggers it, following restarts/boots a day don't cause (solve) the problem.

Anyone else with the same "behaviour" ... any ideas how comes?

Hello, 

Thanks for reaching out to us. Can we try the steps mentioned in this forum?

https://www.dell.com/community/XPS/Dell-XPS-DPC-Latency-Fix/td-p/7367700

Hi Vijay,

not sure why I should follow things like the step mentioned in the link since I dont have an eGPU Dock attached to my Dell. 

Nevertheless did the applicable things from the linked thread and deactivated the UHD Graphics Card, disabled UHD Audio, deinstalled Realtek Drivers and so on (I am not using the internal sound card at all - I am on an external Interface). Now my laptop runs on the built in Quadro 1000. Result is I cannot adjust screen brightness anymore but hitting the screen brightness buttons will have the same ACPI.sys DPC latencies of over 6ms mentioned in my previous post. 

Regards

Karsten

Hi there, I know your post was done almost a year ago, but I’ve just purchased a top of the line RME ufx+ thunderbolt usb3 interface. RME drivers are world class. The issue is with DELL, and is the same wether using usb2, 3 or thunderbolt. I’m currently scanning all possible fixes and and then rme forum support suggested process lasso as well and various other fixes, this is the ongoing thread:

https://forum.rme-audio.de/viewtopic.php?pid=148389#p148389

there’s a very interesting discussion going on about windows vs mac as well.

If and when I improve the performance of the Dell XPS i9 top of the line audio throttler, I will post the solutions that worked.
In the meantime if anyone has an updated fix for this issue I’m very much interested ! 

Yes you will most probably the issues you mentioned: delays and worse, audio glitches and pops, especially in live situations.

Although you could be lucky and have no issues, unlucky imho.

i have XPS 15 core i9, rme ufx+ (world class sound card) and dell is the issue.