DPC Latency: What is it, Does PCAudioLabs Test for DPC Latency?
DPC latency is, simply put, the enemy of music production.
In this article, we’ll talk about what DPC latency is, if PCAudioLabs tests for DPC latency, and how our Rok Box Pro Audio PCs are better at ensuring that DPC latency is not a concern when you’re producing music.
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What is DPC Latency? Does PCAudioLabs Test for DPC Latency?
DPC latency stands for Direct Procedure Call Latency.
When a driver in your Windows operating system requests access to system resources, it generally needs to sit in what is called a wait chain — think of it as the queue outside a club.
Everyone wants to get into the club as quickly as they can — they want to get to the party!
But, the bouncer at the door needs to ensure that people are only let in when they should be allowed in.
Sometimes, someone tries to jump the queue — that’s not fair to everyone else! And that causes problems.
In digital audio production, when a driver for a device installed in your PC requests to jump ahead of the queue, it can cause DPC latency, which can lead to pops and clicks in your audio, or even worse, system shutdowns and crashes.
Generally speaking, drivers that are most at fault for DPC latency are those used by Graphic Processing Units (GPUs). These drivers are accessed often, and therefore they may be pushed up the wait chain. Windows is good at ensuring that everyone gets into the club when they’re allowed to be, but an out-of-date or problematic driver may cause an issue in the wait chain.
Other drivers in a PC can cause issues, including, but not limited to, audio interface drivers, networking drivers, USB peripherals, and myriad other devices.
If not kept in check, DPC latency can cause many issues in audio production.
But, in a properly built and tested Pro Audio PC, such as the PCAudioLabs Rok Box MC series of Pro Audio PCs, DPC latency is much less a concern than it would be on a typical off-the-shelf PC such as those from Dell, HP, and other PC manufacturers, who do not account for DPC latency and the needs of digital audio production.
Alright, PCAudioLabs Tests for DPC latency. So, prove it!
Don’t worry, we will!
We’re often asked, “Does PCAudioLabs test for DPC latency?”.
The answer is always yes.
It’s important to keep in mind that DPC latency depends on many factors.
Out-of-date drivers, BIOS/Firmware images, and problematic hardware are all common causes of DPC latency.
Some hardware simply causes DPC latency. We’ve had customers call us after building their own PC, stating that they simply cannot clear a DPC latency issue, regardless of how hard they try.
Unfortunately, some hardware may cause these issues, and simply not be suitable for audio production.
That’s why having a Pro Audio PC built by a seasoned and professional PC builder like PCAudioLabs matters. We test our components, and we ensure that they are suitable and reliable for audio production workflows.
When we build your Rok Box Pro Audio PC at PCAudioLabs, we thoroughly test your PC’s components for stability and DPC latency. This is accomplished by utilizing many applications, including BurninTest Pro from Passmark software, and latencymon, from Resplendance software.
To test for DPC latency, we’ll run audio playback through an audio interface and a Digital Audio Workstation, in the case of this blog, PreSonus Studio One.
With audio playing back, and some popular plugins instantiated (in this case, iZotope Ozone 11, LANDR Mastering Pro, and IK Multimedia T-Racks CS), we’ll launch Latencymon, and allow it to run in the background. The application will scan DPC wait chains for possible interrupts, and then report to us if there is an issue. If an issue is identified, we will then locate the problematic device or driver, and correct the issue. No system leaves our workshop without having had these tests run.
We run our Latencymon test for at least ten minutes. In our experience, within ten minutes, if a DPC issue is going to happen, it will make itself known.
The test Rok Box Pro Audio PC Configuration
Our test system in this case is a Rok Box Pro Audio PC built with the following specs:
- Intel Core i9 12900k CPU
- ASUS ProArt Z690 Creator Wifi Motherboard
- 128GB Corsair DOMINATOR LED RAM
- Windows 11 Pro
- Universal Audio Apollo Solo Thunderbolt Audio Interface with Buffer size settings of 128 samples.
- PreSonus Studio One 6.6
- LANDR Mastering Pro, iZotope Ozone 11, IK Multimedia T-Racks CS
- Audio playback in Studio One is 48kHz, 24-bit.
Testing for DPC Latency Methodology
Testing is simple. We will play back audio from our test Rok Box Pro Audio PC while running Latencymon in the background. We’ll open and close plugins, make changes to their settings, stop and start playback, and other actions that someone would likely take whilst using their PC for audio production.
We’d also like to note that in this test scenario, other applications are open and running in the background, namely, Google Chrome, which is known to be a memory-hog.
We’re also connected to the Internet via Wi-Fi, with various other applications running in the background.
In a standard, off-the-shelf PC, these additional applications would likely cause DPC latency issues.
Below, you’ll find screenshots of our process of testing for DPC latency, along with the associated timestamped screenshots from Latencymon. This will help to answer the question, “Does PCAudioLabs Test for DPC Latency?”.
As you will see from these screenshots, no DPC latency was found during our test run.
Closing Thoughts About DPC Latency Testing
We hope that you found this article to answer the question, “Does PCAudioLabs Test for DPC Latency?”
Other PC manufacturers and builders are unlikely to perform these tests as we do.
We choose PC components that we know will be ultra-compatible for audio production and are also not prone to DPC latency issues.
Your mileage may vary on your PC, specifically as you install new hardware or software.
It’s important to always keep your drivers and Operating System up to date. If you don’t, you may find that you have DPC latency issues.
When your PCAudioLabs Rok Box is built and tested, we install all the latest drivers, BIOS updates, and tweaks needed to ensure that your PC is Rok-Solid for music production.
If you have questions about our testing methodology, feel free to contact us via phone (615-933-6775), or email us.
Thanks for reading, and happy music-making to you!