Discussion: NVIDIA Display Driver (nvlddmkm.sys) DPC Latency

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Seems like I was logged into another account when writing the last post... quick update: on 22H2 the IrqPolicy fix loses effect after a reboot. I have to toggle between settings so the device (GPU in this case) gets restartet. The restart of the device together with the IrqPolicy seems to be the fix (for 22H2, 21H2 works fine after a reboot). Not a practical solution though.

I'm staying on 21H2 for now as 22H2 is buggy. If I'm bored over the free days I might try another run on a fresh 22H2 installation.
 
Re: last few tests with affinity

Delete Mask: this is basically just "reset to default". A mask is only set if the driver adds the proper registry keys during installation and/or if you set a mask manually. I.E. deleting a mask if you haven't set one won't do anything, the credit was accidentally given to this setting, but something else was responsible for the latency changes. The only way to be sure is to repeat all the steps a few times until you can replicate it every time with ease, then you'll know for sure what happened.

22H2: this version has major performance issues right now and I can't recommend it to anyone, not even casual computer users. The Task Scheduler is broken, it has some sort of permissions issue that causes it to not finish its tasks, and then it continues to run forever until reboot. Microsoft hasn't acknowledged it yet because they're on vacation. They also enabled GPU debugging on the W11 version by mistake, so make sure to download KB5020044 to fix the gaming issues. Lastly, AMD users are also reporting much lower framerates in this update too, which hasn't been addressed yet. These are just the known issues right now, and I bet more come to light in the next month or two as people update to the new 22H2 and spend more time with it. More virtualization is also being added, so turn virtualization off at the BIOS if you are a gamer because that stuff hurts performance. If virtualization was turned on in the bios, it's recommended that you do a clean install of Windows after disabling it.

Interrupt Affinity: I really didn't want to mess with this, but I can see that it's going to keep being brought up on the thread, so I'll spend a day on it and see what I come up with, in terms of trying to make a fix that people can easily implement. I have some ideas I've been thinking about that I want to try. The advanced policies, such as IrqPolicyOneCloseProcessor that was mentioned, are quite similar to some of the settings I saw in the power plans. I am just on the fence about touching this stuff because this is system-wide tweaking here, and I can't be sure it will be compatible with every combination of hardware/drivers that people use, so it's a risky thing to play with. The last thing I want is to brick someone's machine. We'll just have to go through a few trial phases I guess on the thread, and get people to test it out that are willing to reformat if necessary, until we find a "safe" fix.

Because this is Christmas weekend though and I have family visiting and such, I probably won't be able to report back until next week, unless I stumble on something lucky today.
 
Hellbovine said:
Interrupt Affinity: I really didn't want to mess with this, but I can see that it's going to keep being brought up on the thread, so I'll spend a day on it and see what I come up with, in terms of trying to make a fix that people can easily implement. I have some ideas I've been thinking about that I want to try. The advanced policies, such as IrqPolicyOneCloseProcessor that was mentioned, are quite similar to some of the settings I saw in the power plans. I am just on the fence about touching this stuff because this is system-wide tweaking here, and I can't be sure it will be compatible with every combination of hardware/drivers that people use, so it's a risky thing to play with. The last thing I want is to brick someone's machine. We'll just have to go through a few trial phases I guess on the thread, and get people to test it out that are willing to reformat if necessary, until we find a "safe" fix.
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You can just start the tool and see what's the current setting (should be no mask) and revert back to that after you are done testing. Not complicated and I don't see how you could possibly brick your system doing that. It fixed the problem completely for me on 21H2. The mask that was previously set on my 21H2 installation was probably due to NVCleanInstall and me messing with settings in there (only thing that I can think of).
 
An update about Windows XP. I was loaned an ISO (thank you!) to install and so I got around to testing a few things this week that I had hoped would help in tweaking W10, here's some notes on those findings:

XP DPC
Necrosaro asked me many moons ago if I had changed my hardware after moving from XP to W10. This was brought up because I said I didn't have DPC issues on XP. I couldn't answer him with 100% confidence because honestly I was having a hard time remembering everything since it had been a while and it was complicated--I had my original gaming machine, but then my father gave me his which had equally good parts, so then I combined them by mixing all the best parts into one frankenstein machine. Before I did that, they for sure didn't have DPC problems on XP, but now that I combined them I couldn't answer this question anymore, until now. After installing XP on this frankenbuild, it indeed had zero DPC issues, never spiking above 50 microseconds, even with the latest XP supported Nvidia driver installed.

VISTA
After playing in XP again after spending so much time tweaking W10, it's become very clear to me that *all* Windows problems that we complain about today, stemmed directly from Vista. The move from XP to Vista was too big of a leap, it became too bloated and security heavy, and the performance issues in gaming today all come from this transition. W7 is really no different, it's more bloated than Vista, but I think Microsoft managed to make it so popular because they actually spent the time on PR (public relations) listening to feedback about the flop that Vista was, as well as the huge number of people refusing to leave XP, and so they went to work fixing up W7 to address those complaints. In other words, they actually listened to the average user, and it paid off immensely because W7 adoption skyrocketed.

POWER PLANS
I tried everything I could think of regarding power plans in XP. If I'm understanding correctly, the reason this was a non-issue on XP is simply because there wasn't really such a thing as a power plan. What I mean is, yes they had several power plan choices, but they were only manipulating a half dozen settings, and they were very simple settings too: monitor timeout, hard drive timeout, etcetera. There was only 1 CPU option, which throttled it down if enabled, but if you used a plan like "Always On" then this was disabled. So the takeaway here is, now we have 142 power plan settings, and most of them are some form of power savings. To get back to an XP era, you'd basically have to just properly turn all the throttling off in every setting. It's doable, and I'll do it eventually, it's just extremely time consuming since so much is undocumented and it takes a lot of testing.

NOSTALGIA
After seeing XP again, it makes me want to go back, lol. Everything was so much simpler, it just worked. You can literally "feel" the difference, it starts up fast, nothing is going on in the background, it just does what you tell it to do. A clean install had somewhere around 4000 handles, 250 threads, 15 processes, and used less than 150 MB ram (trying to remember offhand without double checking). There was barely any tweaks necessary, I just need to disable system restore, firewall, windows update, change power plan to always on, adjust the pagefile, and a few other misc clicks like disabling antivirus monitoring in the security health center, etcetera. It's crazy how simple it was, no autologgers, no scheduled tasks, it was truly *your* machine rather than being Microsoft's machine.
 
aurox87 just because you cant see something breaking a system doesnt mean that it couldnt happen, you know EVERYTHING do you? can you absofikkenlutely guarantee that that will NOT break a system? no you cannot!
 
Hellbovine remember the XPerience tiny xp iso's? thats where i found a very interesting reg file called "maniac services", it leaves xp with just 4 running services and it runs like a dream. i still think that deleting settings in a plan might be the way to go.
 
aurox87 said:
What's the point of that comment? If you don't want to change things on your system that's fine.
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Don't take it personally. All Clanger means is that your comment is kind of naive. I thought the same thing when I read it too. When you've played around in stuff for as many years as some of us have, you've had your share of bricked machines and learned the hard way that the most innocent of settings can have dire consequences when toggled. Because the reality is none of us actually know how Windows works. It's not open source, and all we are doing, even NTLite, is guess and check trial and error. Sure, after doing it hundreds or thousands of times you start to resemble some form of an expert, but we're still all just playing in Microsoft's sandbox.

The other thing to consider is that there is so much 3rd party stuff too. Drivers are notoriously buggy and poorly written, as are game engines and netcode for multiplayer gaming, etcetera. There's just so many variables to consider is all Clanger is saying. It's just a friendly reminder that even the simplest things can bork Windows. I don't say this to make you look bad, but look at the mistake you made earlier, thinking that deleting the mask was the fix. It happens to all of us, please don't get me wrong, I make mistakes all day long. Our point is a lot of the tweaking people do is actually not safe at all. Just because it doesn't brick their machine, doesn't mean it won't brick others. Look at Zefir001's simple reg keys for the Nvidia service, I couldn't even get into safe mode because of those, but he had zero issues.
 
its no naive to expect that something may break a system and to use either a vm or a test pc because i have done it myself and see many others get up crap creek many many times by doing something on their main(only) machine and it breaks. when im bareboning windows 7 down to 1.16(1.26?)GB installed or bareboning services on a test install i expect it to break and it has done many times but i prepare for it by using a vm or a test install/test machine.
 
Clanger said:
its no naive to expect that something may break a system and to use either a vm or a test pc...
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Yeah I'm agreeing with you. Test, test, test, then test again. That's the moral of the story here for everyone. As we've seen in this thread, that just doesn't get done properly by the majority of people, even the ones that are advanced techies will cut way too many corners and get too excited that they "found a fix" and won't test it a 2nd time or retrace their steps to confirm what they did, etcetera.
 
i can go further than 99% here because of my needs which will break other peoples machines many times over, i know that but i still share stuff anyway. i was bareboning scheduled tasks and sharing the results here 2 years before nuhi added Scheduled Tasks to the tool.
You need a few maniacs to test the hardcore stuff be it removals or tweaks.
 
Clanger said:
...remember the XPerience tiny xp iso's?...
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I never got into heavy tweaking on XP, because I never felt I had a reason to. For me personally, the vast majority of all issues I experienced on XP was directly related to the software I was using. Most of my time spent tweaking was in dissecting game cfg files and figuring out how to optimize their crappy settings and improve the netcode (as well as router/network settings) so when I shoot people the bullets would actually register. Now to be fair, this was SP3. Like every Windows, even XP started off with some bumps in the road, I remember moving from 98 to XP and I was like "ugh this is crap", but Microsoft actively worked hard on XP and fixed it up.
 
i had conniptions when i first got into w7 about 4 years ago. fat bloated and a resource hog compared to xp, now i have conniptions comparing w10 to w7, even more bloated and resource hogging. i cannot make w7 8.1 and w10 perfect but i can make them "acceptable" providing i compromise.
 
Hellbovine said:
Don't take it personally. All Clanger means is that your comment is kind of naive. I thought the same thing when I read it too. When you've played around in stuff for as many years as some of us have, you've had your share of bricked machines and learned the hard way that the most innocent of settings can have dire consequences when toggled. Because the reality is none of us actually know how Windows works. It's not open source, and all we are doing, even NTLite, is guess and check trial and error. Sure, after doing it hundreds or thousands of times you start to resemble some form of an expert, but we're still all just playing in Microsoft's sandbox.
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Sure, I can't guarantee that changing the interrupt priority doesn't brick your system. Neither can you guarantee that changing power plan settings brick your system. If we want to argue on that level...

What I simply don't understand is why Clanger derails the thread instead of focusing on the actual problem at hand. I've posted what helped for me, that's all. I can edit my original post if it is that upsetting.
 
aurox87 said:
Neither can you guarantee that changing power plan settings change your system
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but you cannot guarantee that they dont. its just an idea that hasnt been tested here yet and cannot be ruled out yet.
what we still dont have is a definitive "do this do that" to fix this issue, stuff works for some and doesnt for others.
derail/off topic is what we do here and isnt strictly or otherwise enforced, Hellcow is the OP so its for him to decide whats derail/OT.
power plans is a suggestion that we attack this problem from another direction that hasnt been tried yet. we all know windows is full of power saving settings and while tweaking or getting rid of them make not work they may do even if they have to be combined with other tweaks.
 
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I think we're all on the same page and the same team here. It's easy to look too deep into forum text because we lose body language and tone of voice, plus there are lost in translation problems too since we have so many international members. I know I'm guilty of this, but we made it 19 pages so far guys, and we have one of the highest ranked Google searches there is for this issue, so we're obviously doing something right together as a team here. Let's keep moving forward together, and not fall down into chaos now :)
 
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