DPC Latency Issue

Hey guys!
 
I've got a 2i4 1st Gen from Focusrite, love it been using it on my HP laptop, works like a charm. Just got a custom built monster PC and was anxious to use it with Sonar Platinum but all audio that comes through the USB interface is crackly, poppy, blendy, and even slowed at times. I reached out to Focusrite and was unable to find a solution. Disabled fast boot, the USB power savers, power management and updated the BIOS to no avail. 
 
My specs ASUS
Intel Core i7-6700K @ 4.00GHz
32 GB RAM
Realtek High Def Audio
GTX 1070
 
My DPC Latency Test:
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CONCLUSION
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Your system seems to be having difficulty handling real-time audio and other tasks. You may experience drop outs, clicks or pops due to buffer underruns. One or more DPC routines that belong to a driver running in your system appear to be executing for too long. One problem may be related to power management, disable CPU throttling settings in Control Panel and BIOS setup. Check for BIOS updates.
LatencyMon has been analyzing your system for 0:06:20 (h:mm:ss) on all processors.

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SYSTEM INFORMATION
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Computer name: DESKTOP-2CNQ6D3
OS version: Windows 10 , 10.0, build: 17134 (x64)
Hardware: ASUSTeK COMPUTER INC., Z170-AR
CPU: GenuineIntel Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
Logical processors: 8
Processor groups: 1
RAM: 32706 MB total

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CPU SPEED
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Reported CPU speed: 4008 MHz
Note: reported execution times may be calculated based on a fixed reported CPU speed. Disable variable speed settings like Intel Speed Step and AMD Cool N Quiet in the BIOS setup for more accurate results.
WARNING: the CPU speed that was measured is only a fraction of the CPU speed reported. Your CPUs may be throttled back due to variable speed settings and thermal issues. It is suggested that you run a utility which reports your actual CPU frequency and temperature.
 
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MEASURED INTERRUPT TO USER PROCESS LATENCIES
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The interrupt to process latency reflects the measured interval that a usermode process needed to respond to a hardware request from the moment the interrupt service routine started execution. This includes the scheduling and execution of a DPC routine, the signaling of an event and the waking up of a usermode thread from an idle wait state in response to that event.
Highest measured interrupt to process latency (µs): 649.709164
Average measured interrupt to process latency (µs): 2.397719
Highest measured interrupt to DPC latency (µs): 647.409761
Average measured interrupt to DPC latency (µs): 0.960707

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REPORTED ISRs
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Interrupt service routines are routines installed by the OS and device drivers that execute in response to a hardware interrupt signal.
Highest ISR routine execution time (µs): 434.452844
Driver with highest ISR routine execution time: dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation
Highest reported total ISR routine time (%): 0.035395
Driver with highest ISR total time: dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation
Total time spent in ISRs (%) 0.057721
ISR count (execution time <250 µs): 261627
ISR count (execution time 250-500 µs): 0
ISR count (execution time 500-999 µs): 7
ISR count (execution time 1000-1999 µs): 0
ISR count (execution time 2000-3999 µs): 0
ISR count (execution time >=4000 µs): 0

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REPORTED DPCs
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DPC routines are part of the interrupt servicing dispatch mechanism and disable the possibility for a process to utilize the CPU while it is interrupted until the DPC has finished execution.
Highest DPC routine execution time (µs): 1827.371507
Driver with highest DPC routine execution time: Wdf01000.sys - Kernel Mode Driver Framework Runtime, Microsoft Corporation
Highest reported total DPC routine time (%): 0.125322
Driver with highest DPC total execution time: Wdf01000.sys - Kernel Mode Driver Framework Runtime, Microsoft Corporation
Total time spent in DPCs (%) 0.172886
DPC count (execution time <250 µs): 987835
DPC count (execution time 250-500 µs): 0
DPC count (execution time 500-999 µs): 1450
DPC count (execution time 1000-1999 µs): 1
DPC count (execution time 2000-3999 µs): 0
DPC count (execution time >=4000 µs): 0

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REPORTED HARD PAGEFAULTS
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Hard pagefaults are events that get triggered by making use of virtual memory that is not resident in RAM but backed by a memory mapped file on disk. The process of resolving the hard pagefault requires reading in the memory from disk while the process is interrupted and blocked from execution.
NOTE: some processes were hit by hard pagefaults. If these were programs producing audio, they are likely to interrupt the audio stream resulting in dropouts, clicks and pops. Check the Processes tab to see which programs were hit.
Process with highest pagefault count: explorer.exe
Total number of hard pagefaults 354
Hard pagefault count of hardest hit process: 110
Number of processes hit: 19

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PER CPU DATA
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CPU 0 Interrupt cycle time (s): 11.066701
CPU 0 ISR highest execution time (µs): 353.273204
CPU 0 ISR total execution time (s): 1.660805
CPU 0 ISR count: 256983
CPU 0 DPC highest execution time (µs): 1827.371507
CPU 0 DPC total execution time (s): 5.177946
CPU 0 DPC count: 970207
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CPU 1 Interrupt cycle time (s): 1.257480
CPU 1 ISR highest execution time (µs): 434.452844
CPU 1 ISR total execution time (s): 0.094937
CPU 1 ISR count: 4627
CPU 1 DPC highest execution time (µs): 507.508982
CPU 1 DPC total execution time (s): 0.047922
CPU 1 DPC count: 5156
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CPU 2 Interrupt cycle time (s): 0.740061
CPU 2 ISR highest execution time (µs): 143.020459
CPU 2 ISR total execution time (s): 0.000841
CPU 2 ISR count: 24
CPU 2 DPC highest execution time (µs): 57.615519
CPU 2 DPC total execution time (s): 0.023433
CPU 2 DPC count: 10082
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CPU 3 Interrupt cycle time (s): 0.744725
CPU 3 ISR highest execution time (µs): 0.0
CPU 3 ISR total execution time (s): 0.0
CPU 3 ISR count: 0
CPU 3 DPC highest execution time (µs): 37.918663
CPU 3 DPC total execution time (s): 0.001068
CPU 3 DPC count: 402
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CPU 4 Interrupt cycle time (s): 0.744677
CPU 4 ISR highest execution time (µs): 0.0
CPU 4 ISR total execution time (s): 0.0
CPU 4 ISR count: 0
CPU 4 DPC highest execution time (µs): 28.505988
CPU 4 DPC total execution time (s): 0.003752
CPU 4 DPC count: 1163
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CPU 5 Interrupt cycle time (s): 0.737013
CPU 5 ISR highest execution time (µs): 0.0
CPU 5 ISR total execution time (s): 0.0
CPU 5 ISR count: 0
CPU 5 DPC highest execution time (µs): 29.263224
CPU 5 DPC total execution time (s): 0.002038
CPU 5 DPC count: 689
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CPU 6 Interrupt cycle time (s): 0.769074
CPU 6 ISR highest execution time (µs): 0.0
CPU 6 ISR total execution time (s): 0.0
CPU 6 ISR count: 0
CPU 6 DPC highest execution time (µs): 24.442365
CPU 6 DPC total execution time (s): 0.003760
CPU 6 DPC count: 1183
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CPU 7 Interrupt cycle time (s): 0.710221
CPU 7 ISR highest execution time (µs): 0.0
CPU 7 ISR total execution time (s): 0.0
CPU 7 ISR count: 0
CPU 7 DPC highest execution time (µs): 41.541168
CPU 7 DPC total execution time (s): 0.001441
CPU 7 DPC count: 404
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Would LOVE some help with this. Been banging my head at it for a week.
 
-Cable

@abacab I listed Realtek as it was the default sound driver on the PC. I disabled speedstep and had already disabled the network drivers. As for performance, all the settings are set for maximum. It's strange, I can't seem to pin the tail on this.

I'm running 256, sample rate is 44.1 same as windows. Does windows have a buffer size? As for drivers, the standard Focusrite 2i4 one found here: https://us.focusrite.com/downloads?product=Scarlett+2i4+first+gen
 
No ASIO4All here

It's for everything: Playback, DAW, YouTube, video games. Everything has the snap-crackle-pop® sounds 

ccable
This is a custom built PC, no integrated graphics just the 1070.

Your Intel Core i7-6700K has onboard Intel® HD Graphics 530. > https://ark.intel.com/pro...M-Cache-up-to-4_20-GHz
 
You Z170-AR motherboard has a HDMI and displayport connections for the integrated graphics.  The Intel graphics should be enabled in the BIOS if no GPU is installed.

Nvidia loads a bunch of software that hampers audio. Two things to try specific to those.
1. Reload nvidia drivers as a clean install, and only check graphics drivers and PhysX.
2. Go into device manager and disable nvidia HD audio drivers.

You say network is disabled, but for others reading this, "automatic network discovery" is one of the top latency issues, and should be disabled.

If WDM mode (YouTube) has problems, the reason should be huge. I mean not related to 1-2ms delays some drivers can have.
As the first, I will try to use it with different USB cable on different port (sure on PC itself, not with some hub).
As the second I will connect it to another PC to check.

Disabled WiFi, already have the interface in a USB-2. Cable is good, I've used it on my laptop for a year. Would removing Realtek (reinstalling) be of any use?

ccable
Disabled WiFi, already have the interface in a USB-2. Cable is good, I've used it on my laptop for a year. Would removing Realtek (reinstalling) be of any use?

Generally speaking, disabling (onboard) Realtek sound won't have an appreciable effect on DPC Latency.
 
If the Focusrite is sharing a root-hub with another USB device, that could cause problems.
Azslow3's suggestion to try a different USB port is worth a shot.
 
From what I read above, the DPC Latency report doesn't mention a problem with 3rd-party add-on hardware/driver.
If you've disabled everything that can affect DPC Latency... and you've flashed the BIOS up (and down) with the same results, the problem may be the motherboard.  Strip the machine down to the barest of essentials (necessary to run).
If DPC Latency is still high, I'd swap out the motherboard.
 
With super high DPC Latency, it doesn't matter what audio interface, how it's connected, etc...
You'll hear audio glitches... as the ASIO buffers don't get filled in time (due to the process monopolizing the CPU).

High DPC Latency will affect *any* audio interface (doesn't matter if it's PCIe, USB, Firewire, or Thunderbolt).
To effectively work with audio, the machine needs low/consistent DPC Latency.
 

I have an ASUS Z170 motherboard and do not have any DPC Latency problems.  

I ran another Latency test, this time at 512 Buffer Size, cleaner sound still with crackle, though not as much and found 3 Drivers with high execution.
 
WDF1000.sys
- ISR Count: 20014
- DPC Count: 20012
- Highest Execution: 0.308
 
HDAUDBUS.sys 
- ISR Count:16054
- DPC Count: 1428
- Highest Execution: 0.144
 
DXGKRNL.sys
- ISR Count: 14626
- DPC Count: 8000
- highest Execution: 0.108
 
 
Before we seal the coffin, any thoughts here?

One thing that might be worth trying and is cheaper than a new motherboard is a PCIe USB card that has only the audio interface connected. I found that solved a dropout problem with a Cakewalk UA-101 interface a build or so ago. For whatever reason the m/b USB was fine with loads of MIDI stuff hooked up but I couldn’t get latency down below about 512 samples at 44.1KHz even if the only thing connected was the interface. Connecting the UA-101 to a dedicated USB board let me drop to 64 samples without problems.

wdf might be part of a driver stack for some piece of hardware in your system. "The web" says many specialized mouses/trackpads use it. For starters, you could go to your device manager and go through each device, starting with mouse and display adapter & anything associated with firmware or BIOS or motherboard manufacturer, do properties, then the Driver tab, then the Driver Details button and look for the Wdf01000.sys entry in the list. 
 
I didn't find it in either computer I looked at, so maybe it won't show in those lists, or maybe not every computer uses it. Edit: wdf01000.sys appears in the driver list from LatencyMon, just not in any hardware driver details I looked at. OTOH it only had 6 ISRs in 30 seconds.
 
Any antivirus involved? Windows update working (Background Intelligent Transfer Service)?