Today’s topic is DPC latency. In windows, DPC refers to a Deferred Procedure Call and in simple terms it essentially describes what your system does when it’s taking too long to process a task. Some times raw power is not the bottleneck in your PCs performance, and your CPU is waiting around the other components to let its work be processed. High DPC latency is often caused by a delay in processing from a problematic driver, but it also takes into account the speed of the system as a whole. DPC Latency is relevant to both trading and audio PCs because both involve a robust system to be able to handle real-time data as quickly as possible, without the possibility of stutters. Traders need financial data to be processed as quickly as it comes in and musicians need to be able to play in real-time, without a delay between when they’re playing and when what they are hearing is played back to them. Of course, there are many fields where latency is relevant but trading and audio are the two areas where we receive the most questions about reducing latency.
The Test Environment
Testing was conducted by modifying the memory’s operating frequency through the BIOS settings and then recording the results of the latency that is polled through a program called DPC Latency Checker.
Brand / Model
|CPU||Intel Core i7-11700KF|
|RAM||G.SKILL Ripjaws V 32GB (2x16GB, 3200 MHz base)|
|Cooler||Corsair H115i Pro XT|
|GPU||Nvidia Quadro P620|
|SSD||Samsung 980 Pro|
|Motherboard||Gigabyte Z590 UD AC|
The result of the test was the modifying the operating frequency of the memory modules did not have a measurable impact on DPC latency. For this reason, we set RAM to operate at the maximum frequency that is it set to operate. In our case the factory RAM speed was 3200 MHz. Running RAM past it’s maximum factory frequency (i.e. overclocking the RAM) drastically reduces the PCs overall stability and opens the door for freezes, crashes, blue screens, etc. that are more likely to waste your time than any time you would save from RAM overclocking. There are negligible performance gains that can be achieved, especially with regards to audio and trading PCs.