This is another one of those tools that people either love or think that it’s completely useless. DPC refers to a “Delayed Procedure Call”, where a driver will receive an interrupt from hardware that requires the computer drop everything to deal with it and instead of freezing up the computer for however long is needed, the driver acknowledges it from the DPC queue, restores control to the program and processes the information when the driver’s own turn comes around.
The issue that can happen with some Windows machines is that for reasons of power saving or poorly written drivers, procedure calls can stack up or just completely flood the queue, causing issues such as sound popping or video skipping. It’s an annoyance if you are listening to a song, but a massive problem if you’re taking multiple inputs and recording them into a song.
DPC Enhancer is a small tool made by Smithson Martin, who make various tools for music production and it’s something that turns out to be oddly useful in day to day computer use, especially on computers with multiple video cards. One of the things that this tool does is update normally non-accessible power settings on computers with multiple video-cards and insure that both cards are powered on all the time. If you’ve bought a recent model laptop and noticed that the desktop is oddly non-responsive, odds are that your secondary video card is going into sleep mode until you press a button, at which point it activates just long enough to process the toggle before turning back off again. It’s something I’ve been annoyed by on two recent laptops, one of my own and one I’ve set up for my parents; in theory the card built into the motherboard should handle all desktop activity and not access the second card at all unless a game is activated. However with system monitoring, I’ve noticed that the power to the second card does change the desktop latency.
Regardless, you may find this tool to be helpful if your new model computer is oddly non-responsive, in sound production, gaming or just on the desktop. Smithson Martin no longer offers it for download, but I have provided a copy here. Simply run it in the background for it to work, it helpfully minimizes directly to the task bar.
If you work for Smithson Martin and want me to take the link down, please don’t hesitate to contact us.