M17x and DPC Latency

If you don't want to manually start each batch file every time (for example, if you tend to forget to resume the threads before shutting down the system which causes the system to not properly shut down), you could just add the restore script to your Windows shutdown and logon script in the group policies editor (you can also run the suspend script as a startup script if you're comfortable with it, or simply add it to your user startup folder, which is safer in my book).

To do add the script to the shutdown scripts, follow the following steps (Warning! Use at your own risk, as suspending the ACPI processes could have adverse side-effects - please test it thoroughly before adding it to startup or shutdown to make sure it works on your system! I also suggest to create a system restore point or full backup before you try this):
1. Press Win+R.
2. Type in gpedit.msc.
3. Click OK.
4. Click on Local Computer Policy -> Windows Settings -> Scripts (Startup/Shutdown).
5. Double click on Shutdown on the right hand side.
6. In the Scripts tab, click on the Add button.
7. In the Add a Script Window, click on the Browse button.
8. Select the ACPI resume script file you've created following Winslayer's instructions (.cmd or .bat).
9. Click Open.
10. Click OK.
11. Click OK again.

This will now run your .cmd or .bat script file whenever you shut down Windows and thus resume the ACPI processes to allow it to shut down properly.

You can do the same with Startup scripts. The user logon/logoff scripts can be found in Local Computer Policy -> User Configuration -> Windows Settings -> Scripts (Logon/Logoff) and can be edited the same way (I'd actually recommend to add the ACPI process resume script to the logoff script as well). I do recommend not using the Startup and logon scripts, however, and just place a link to them into the Startup folder of your user profile instead, so you can easily disable it in case your system hangs on startup or whatever with it.


Now to find a way to run a script on hibernate, sleep, etc..

 

ok i will try. what about restart?

 

Just add the .bat to your desktop and double click it when you want it run.

 

thats what i did actually. two shortcuts for restore and suspend bat files.

 

Sure. But some may want to run the batch script to suspend the ACPI threads on every startup and run the batch script to resume them automatically when they shut down so the system doesn't hang (even though it's not recommended, as things that rely on the ACPI - like power management functions such as turn off display, dim display, sleep, hibernate, etc. as well as shut down/restart - will no longer work). That's what my instructions are for.
By the way, does anyone know if there is a way to assign a .bat or .cmd script to lid close?

The shutdown script in the group policies will also apply when you restart Windows.

Disabling the ACPI threads really is no good solution. I hope Dell will sort it out with a BIOS update and possible get Microsoft to update the Windows 7 and Vista x64 ACPI drivers as well to get rid of the DPC Latency issues.

 

Yes, the reason why you didn't see the clocks change is that you're running vista and he's on w7. Switching from vista to 7 I noticed the same. But that's a bit OT.

 

I got to using DPC latency checker because my CPU usage was extremely high due to DPCs. Of course there were huge spikes like most of you, so then I suspended the ACPI threads. Now all the bars are green most of the time, but I am still getting the same annoying CPU usage. My laptop is completely unusable. DPCs spikes up to 50% cpu usage all the time, along with a few other system processes.

edit: Nevermind. It still spikes like crazy when I try to do something. It only stays in the green when I'm idle. I'm using the latest nvidia drivers.

 

Having tested with the ACPI threads suspended with ProcessHacker for a while now, I must say that I have come to the conclusion that I've been indeed suffering video as well as audio stuttering issues in games before, I just never really noticed as they didn't appear that severe for me.
But now, running with the ACPI threads suspended (and powermizer disabled), I notice how much better my system runs in games - the framerate is far more stable, there are no more "slow-motion slowdowns" in games, no stuttering with video or audio and I can play with higher FSAA levels with decent performance. Plus, I don't hear crackles and pops when listening to music or slight video stutters when watching videos anymore (I attributed those to the files themselves before) nor does streaming video on websites buffer as often as it did with the ACPI threads enabled and runs more smoothly. Oh, and I can actually record audio flawlessly now. I guess this DPC latency issue really does affect my overall system performance. I really hope Dell will be able to fix it soon so we won't have to rely on hacks and workarounds.

 

maybe i have to notice that i used a clean win7 dvd (actually installed from usb). Alienware info easy to intergrate.. so i have done a clean install and not upgrade which i never do.

yes i actually believe those spikes maybe related to cpu usage as well. when in idle all bars are green as well (with acpi.sys files suspended of course). when gpus downclock (after exiting games) i get red spikes -audio stuttering. but i also get them when i am loading webpages which actually maybe due to cpu usage. in this second case audio stuttering or not maybe due to the level of cpu usage

 

Trying out the process hacker method now. It's nice seeing the bars where they *should* be. So far no issues other htan losing the media strip lights and functionality. Not too much of a concern!

I'm on Vista 64-bit by the way. Restarting now to see if I set up the .bat files as well as startup/shutdown scripts properly.

 

ok so I'm having trouble shutting down the M17x adding the resume.bat to the shutdown script. Resume.bat on its own works to re-initialize acpi.sys (and brings back the lovely DPC issues). So I'm not sure if it's an issue where Vista tries to run everything at once and the resume script needs to be run FIRST. So for now I'm just going to need to get into the habit of resuming acpi.sys every time.

My media buttons are back and working again. Don't know why those went away...

As far as latency, only a couple minor hiccups in sound, and video is so much more smooth. Sins of a Solar Empire is amazingly faster now - and I'm talking about on huge with large fleet sizes and at 8x play speed. w00t!

 

SUCCESS!!!

I added the resume.bat to the logoff script and voila! It took a little longer than usual to shut down, but it shut down w/o any issues. I guess acpi.sys needs to be enabled before logging off, since Vista logs off before shutting down.

Also, I have not encountered any spikes except when the cards change clock speeds, which has been drastically reduced on the 195.81 drivers. booya

In addition, I can finally re-enable all my "typically unused" devices!

 

Update!
I managed to install Ubuntu 9.10 linux on M17X with minimal tweaking (after 3 reinstalls ) and everything works (video/audio/wireless/linuxOSD/etc) NO STUTTERING and NO AUDIO POP-UPS. Video drivers work better than the current 195.XX with no strange clocking/ clock lockups etc. Still testing the rest of the drivers. But already I'm satisfied with the progress. Next I'll try to put VMWare Player, create a virtual Windows7 and run some games. If anyone interested in trying a dual-boot with linux, - join!
Compiz Rulez!

 

Audio works under Ubuntu? Nice. I had tried a few months ago but had problems... SLI worked just fine with the linux drivers but not hybrid, maybe I should try again. About VMWare I am not sure if you will be able to run any games. I used to play HL2 using winehq. You could start a new thread and now that I have more free time I will give it a shot too.

 

Xmas and still no fix from dell, blah. Soon I might be tempted to try the workaround in the previous posts.

By the way, if you are desperate for a smooth gaming experience, Serious Sam II is stutter free. It runs flawlessly under vista

 

Both Wine and Cedega aren't perfect for running current games. My only hope is for VMWare but there might be a bottleneck (CPU/RAM) as it requires a lot of resources to run smooth...

 

Got my m17x today and while i was playing Grid with everything on ultra, there was one race where I noticed the screen froze for about half a second then went back to normal, frame rate was about 60 or so and I heard a slight kick in the audio atleast 2 times.

Could this mean I have DPC lat problems? I sure as hell hope not...

 

You sure have that problem just like everyone else. It actually doesnt bother me much tho since game and music are all smooth as hell. I think it bothers who do the recording and stuff.

 

well I ran the dpc lat test and I have to say I almost crapped my pants. Looks like I Have it too...so far it hasn't effected gameplay much. Luckily I dont have the giant red bars that reach the top of the screen, just medium ones so its not THAT...bad...

 

Hey guys,

BatBoy asked me to run the DPC latency check on my M15x to compare and here's the results:



The biggest spike I saw was to 1000 microseconds and that was when I had Hulu playing + Pandora and I was overclocking/downclocking the GPU purposely to see if I'd see a red bar spike. Looks like the DPC issue doesn't exist for the M15x but we've got throttling to deal with so neither system is problem free unfortunately.

 

Thanks for testing the M15x Joker. Very interesting to see those results.

 

Jokers results have me thinking it is maybe the nvidia chipset causing it

 

Well, FWIW, the XPS M1730 suffers from the same lag spikes as the M17x. The XPS M1730 uses a Intel PM965 chipset.

 

Jeez :S this is like an epidemic...this problem has to be stopped...

 

Go back to the first couple of pages of the thread. Its a common issue on several models/makes. Its not just a "Dell/Alienware only" issue.

 

to those of you who paid with visa, master card or amex I believe you have a 90day purchase protection in case somethings wrong I think, like in this case, so I believe you could always get a refund

 

well heres what mine looks like



How serious is this...it only effects 2 games, simcity societies and sims 3. I hope it stays that way...

 

Thats bad, just as bad as anyone who have a quad CPU and running Windows 7

Its a little better with Vista, but still bad enough.

 

So its also quad core related?

 

yep, though my pc's dpc isn't caused by the cpu, it's directly linked to the root of gpu downclocking wich i read that my card had a wierd bios to save energy

i'm not willing to change my card's bios though, i'm not that experienced, but i will get a new card soon, cause i tried my brother's 275 and i had no roof top latencies no matter what i did to it, even ran prime while downclocking the gpu

anyway, i think we can all agree that the audio sutters are definitely caused by those high red bars wich is the gpu

 

Not exactly. But Quads seems to have a higher average latency than dual core CPUs, i know this for a fact as i had a dual core before switching to quad core. But the stuttering issue is occurring on all CPUs regardless and its not worse than the other. Also its very bad in Win7.

 

I just wanted to take the time to thank you M17x users that figured out the Process Hacker workaround. Because it disables ACPI, it doesn't allow the bios to mess with the i7's CPU throttling and as a result, the M15x's throttling issues have been completely resolved according to my initial tests. Once I test some more tonight, I'm going to add the instructions to the M15x thread.

JohnBatDell: You guys should be fired.

 

Mines not too bad...

On Win 7

I watched it for a couple minutes and it just continues like that. Green to yellow with an occasional spike. I have only noticed it once while playing a game. I guess I'm lucky compared to some people.

 

better then mine :s

 

Well, I'm running on a dual core.

 

Quad...sadly. Well no, quads are great but I heard its more dpc

 

It doesnt matter if you have green bars or not. As long as you see a big spike(like the one you have on that shot) then you have a problem. Everytime you see that big spike, audio/video will stutter. I am fairly sure that every M17x with windows 7 has this issue.

Dell/AW should be sued for this, seriously. I have never seen a laptop with a latency this bad as the M17x.

 

John from Dell seems to be on holiday or something else happens. still no fix and i am sure they begun testing for a new bios before they officially anoounced they try to.

Maybe they found that it cant be solved and JUST TRYING TO SELL THIS MACHINE WITH THE HOPE OF A NEW FIX!

my opinion from everything i ve read all those years with dcp latency on notebooks is that: even notebooks dont come with dcp latency or its impossible to fix it (thats what they actually mean by multiple causes of it). ITS NOT A MATTER OF FIXING IT BUT A CASE OF NOT SELLING THEM LIKE THAT! THE MOST EXPENSIVE NOTEBOOK IN THE WORLD WITH SOUND STUTTERING! cases that dell fixed it occur on xps or somethign else i dont remember but they may caused other problems. GPU and CPU downcloking overclocking cause this stuttering. So can someone fix this without affecting normal downclocking -overclocking process? THIS IS THE TRUTH.

and i posted again they still didnt test win7 compatibility on M17X. LOOK
http://support.dell.com/support/top...7BB30D49B2B58EACE040AE0AB6E17263&docid=364604

but they sell it with win7 now on. which actually means they sell it without having test for compatibility? if this is not making fun of noobers (including me, but i forgot mine came with vista, right..) who have some thousand of dollars or euros or whatever to spend then what is it? even my acer netbook of 230 dollars has premium sound without problems.

 

wow I doubt i'll ever buy an alienware again I'll probably just start buying asus instead.

the fact that they keep selling it with the issue is even worse

 

I just checked mine again and it was spiking like my last pic... I left it on and watched a youtube video. While watching the video i pulled the checker up and to my surprise, it stopped spiking. Have no idea why it does this but through the whole video (10 minutes) there was not a single spike higher than 4000us. After the video was over, I closed out of the window and still no spikes... About 5 minutes later it started showing spikes again. Thought that was weird and just wanted to post here. So for me I really have had no problems with stuttering. I'm going to try testing it in a bunch of different situations and see what happens...

 

Most likely that's your video card changing clocks. It does this to save power which makes sense for a notebook if it's on battery. The problem is that when it does this, it causes the large red spikes.

 

Shame Nvidia haven't given us an option to disable powermizer completely like in the old xp days.

 

My setup is Hybrid and 'High Performance' with all the power savings settings off in the power control panel. My DPC readout is mostly green/yellow with an occasional red spike into the 2000-4000 range.

 

wth sli on mines not much different...small green bar then medium red bar with long bar every 10 or so red bars....

 

I just downloaded Ubuntu 9.10 64 and will play with a dual boot install as well. I'm going to do an image backup in Acronis first.

 

That's normal for a dual core CPU. The spikes are likely caused by the video cards up- and down-clocking.

 

I used both (had to reinstall a few times). Ubuntu has its own - Gparted (very good utility).

 

News from AW employee:

Bios A03 is due to be released on or before the 2nd week of januari 2010...
And resolve all the stutter/DPC latency issues.

Fingers crossed.

 

Yeah I'll believe it when I see it.

Where did you hear about this anyway?

 

I'd like to know where that info came from too.

It hasn't been updated here yet:

http://en.community.dell.com/blogs/direct2dell/archive/2009/11/18/dell-dpc-latency-and-you.aspx