Dell pledges a new date for fixing the XPS 15 9570's DPC latency issues

Have you ever had someone breadcrumb you? Breadcrumbing, for those who have not heard of it, is where someone leads another person on by dropping small pieces, or breadcrumbs, of information to keep them interested. Well, it sure feels like Dell is doing so to owners of the XPS 15 9570 with the machine's ongoing DPC latency issues.

DPC, or Deferred Procedure Call for those who have not read our previous articles on the matter, allows drivers to execute tasks and the system to prioritise them accordingly. Buggy or poorly written drivers can eat up resources by making numerous DPC instructions. In turn, these bad drivers can cause audio stutters and glitches as the system struggles to prioritise audio playback over multiple instructions from other sources.

The XPS 15 9570 has been suffering with DPC-related latency issues since it launched last year, and Dell has struggled to get a handle on its root causes. Earlier this month, Frank Azor reported that the latency problems were as a result of "a few issues stacking up on one another". Previously, Dell promised to have a solution released by April 16 but went quiet when that date came and passed without rolling anything out.

Now, Azor has released the following statement:

We found a few more opportunities to improve/virtually eliminate the DPC latency, so we took the time to implement them.  We are completing our final validation of the BIOS solution.

Dell has now pledged to release a new BIOS revision in the first week of May, which is between May 1 and May 5. Effectively, the company has stated that it needs another two weeks or so to release a fix. We hope that the similarity in timings is just coincidental and not something that Dell will repeat in two weeks time.