DPC Latency, i7 6700k / 970 / Maximus VIII Hero

Hi,

For the past week I've been wracking my brain trying to understand what's been causing these results in Latencymon:

http://i.imgur.com/gpbBghw.png
http://i.imgur.com/9yhvF60.png

So far, I've tried:

• Swap gpu, drivers, and pci-e slot
• Use integrated audio (previously Xonar Essence STX)
• Remove any hdd besides ssd Windows is on
• Set to High Performance power settings and disabled Speedstep, etc.
• Remove any non essential USB items
• Memtest86+
• Disconnect Ethernet
• Disconnect UPS

I'm at the end of my rope - I have all the latest drivers, and only those, formatted each time, multiple times on w7 x64 and once on w10 x64. It seems to have alleviated when I tried some LAN drivers on Intel's website, but it's still there.

I've seen a few people complain about issues with this and i7 6700k, so I'm wondering - am I missing something? Is this normal?

Thanks for any help, like I said - am desparate at this point.

Tried disabling HPET in BIOS? All of C states?

More than likely it is the new Z170 platform having 78 billion different USB controllers, those and their drivers are the biggest culprits normally. Also, check if your OS is using HPET or not, that can have some effect.

FYI, system monitoring programs like CPU-Z or HWMonitor causes DPC latency to spike. I, like you was tearing my hair out over what the heck was causing my DPC latency to spike, I tried everything and nothing alleviated. Until I decided to leave CPU-Z and HWMonitor closed and BAM just like that my latency fell immediately and consistently too. I am using Core Temp and it causes no issues with DPC

Thanks for the replies so far -

I've tried disabling all the C states, didn't change. I can't find HPET in bios, I think I read Asus doesn't allow disabling it?

I also disabled some of the unused USB controllers, and any onboard devices I don't use (audio), so I don't have the drivers even installed for those. (No exclamation marks in Device Manager).

Not sure if Windows was using HPET, disabled it, it seems a bit lower, still there though.

Not using CPU-Z or other hardware monitors during Latencymon.

I'm mostly getting the red spikes when playing games and the Nvidia driver hits those high execution values, general browsing seems fine (at worst dark greens in Latencymon). I'm starting to wonder if I should bother being worried and just let it be?
I had some audio crackling in a game, but after formatting for the upteempth time I'm not getting it anymore, and it seems more or less stable.

Switch all applicable devices from Line Based IRQs to MSI.

http://forums.guru3d.com/showthread.php?t=378044

Read the entire thread before you do. Just don't go wholesale and attempt to switch everything to MSI, or you will screw your OS install. Take your time and do one at a time. Back up if you need to before you start.

I've switched the 970 to MSI, I'm a bit tentative to change the others as I don't have replacements or other ways to boot Windows if they do fail. Device Manager: http://i.imgur.com/oYm7Eed.png

I also just rebooted while applying it to the HD Audio Controller, and all my USB devices stopped working. Another reboot, and they worked again. I'm not sure how to take that info(controller has MSI activated now though). Also, why is the Nvidia driver the only one with such high execution(ms)?

So, I've been trying some other things out - I noticed the games I was testing were online mostly; I tried disabling Bitdefender while playing, and Latencymon is now like this: http://i.imgur.com/7ps7n7t.png

Still not great, but could it be network-related (or possibly just Bitdefender)? My LAN drivers were by default MSI though, so I don't know what else I can change now? I kinda give up on being able to do anything Nvidia-wise even though nvlddmkm.sys highest execution is 1.29ms, everything else <0.25.

Any suggestions on a more lightweight antivirus / firewall solution are appreciated too.

edit: I realize I double-posted, apologies - felt like a breakthrough so got excited after over a week of this.

Ever since Sandy Bridge I've found the DPC latency monitoring software to be completely useless and inaccurate (I've heard that's it's even more irrelevant in Windows 8/10). Do you actually have any issues? Do you get audio drop outs and freezes that you shouldn't be getting?

kalston said:

Ever since Sandy Bridge I've found the DPC latency monitoring software to be completely useless and inaccurate (I've heard that's it's even more irrelevant in Windows 8/10). Do you actually have any issues? Do you get audio drop outs and freezes that you shouldn't be getting?

Click to expand...

Yes - I had audio popping issues previously, and after various formats and testing, I was still having hiccups / lack of fluidity issues in games; after uninstalling Bitdefender, these seem to have more or less disappeared.
At the same time, Latencymon's results have improved, even if it's showing some issues are persisting.

I'm still curious as to how this is happening though - I installed Kaspersky's Total Security trial, and it gave me some minor hiccups as well.

edit: on a hunch, tried Bitdefender without the firewall part(left Windows) - things seem okayish now as well. Why would the firewall cause this kind of trouble though?

Try disabling core parking and uninstall/disable all resident programs/utilities.

Zono said:

Yes - I had audio popping issues previously, and after various formats and testing, I was still having hiccups / lack of fluidity issues in games; after uninstalling Bitdefender, these seem to have more or less disappeared.
At the same time, Latencymon's results have improved, even if it's showing some issues are persisting.

I'm still curious as to how this is happening though - I installed Kaspersky's Total Security trial, and it gave me some minor hiccups as well.

edit: on a hunch, tried Bitdefender without the firewall part(left Windows) - things seem okayish now as well. Why would the firewall cause this kind of trouble though?

Click to expand...

Your motherboard has the Intel I219-V. You could be experiencing issues with latency because of the NIC. I found this out the hard way, and battled it for the longest time.

I make my own music. Any kind of latency is absolutely KILLER to any music production, because latency = pops/clicks/stutters. And what made it even worse was that it was completely random.

I found out that there is a serious problem with a number of Intel NIC drivers introducing latency. Seems that Intel hasn't gotten a handle on it, although I admit I have NOT tried their newest drivers.

Bottom line: an older driver fixes the issue...but not for your board. In the thread there are at least 2 people who have the exact same board as you and are reporting this problem. Have a look here.

https://communities.intel.com/thread/54594?start=0&tstart=0

Unfortunately, the problem still seems to exist. The people who have your board are still having the issue, according to the thread, so you might be out of luck. Try installing the absolute latest drivers for the NIC, and if the issue persists, try with Windows 7 (someone reported that it's fixed on Windows 7 but not 10).

jyi786 said:

Your motherboard has the Intel I219-V. You could be experiencing issues with latency because of the NIC. I found this out the hard way, and battled it for the longest time. [...]

Click to expand...

Thank you, this makes so much more sense. I uninstalled my current drivers (which were from the Asus website I believe), and tried to DL the latest from Intel - and well, it seems better. Probably not the best it could be, but at this point - I don't see any more audio issues, pretty rare issues in games, so I'm just going to take it.

If it helps you(or anyone else), I'm on w7 x64 and DLed the 20.4.1 version of the Intel drivers (they're compatible with I219-V even if the site doesn't list them, the driver recognized the controller) here: https://downloadcenter.intel.com/download/18713/Network-Adapter-Driver-for-Windows-7-

There are two things I still don't understand, which I just have to ask at this point, if any kind soul knows the answer:

1) Is it normal for nvlddmkm.sys to have such a high value in the Highest Execution(ms) column? The latest two drivers give the same results. http://i.imgur.com/9yhvF60.png
2) Why is CPU 0 the only one of "8" to have an ISR count? Wouldn't it be better for them to be spread? http://i.imgur.com/8o2qoxe.png

Regardless, thanks all for the help.

I had massive DPC Latency issues with my new Z170 build (see thread in Intel Mainboards section), which turned out to be caused by the Asus AI Suite III software. After uninstalling it DPC latency was back to normal.