Dell backtracks on XPS 15 9570 S3 sleep fix

The XPS 15 9570 may not see a return of S3 sleep after all. Last month, the company proclaimed that fixing the DPC latency issues affecting some XPS 15 9570 laptops had been an "exclusive priority", the removal of S3 sleep had not been forgotten and that it was "working on this next".

If you have not read our previous articles on the matter, S3 sleep, short for System power state S3, allows the system to switch off its processor and other components including the motherboard. A system sleeping in S3 should wake in around 2 seconds and ought to retain all processes that had been previously running. Theoretically, S3 sleep keeps power consumption and interruption upon the end-user to a minimum. S3 consumes slightly more power than S4, for example, but the system does not need to save a hibernation file or reboot entirely upon waking.

Dell removed S3 sleep from the XPS 15 9570 BIOS in revision 1.3.0, which it released in July 2018, and forced the laptop to use Modern Standby instead. Modern Standby should consume less power and wake a system faster than S3 can. However, it has had the opposite effect on some machines, causing high battery drain with the device asleep.

After previously stating that it would address the removal of S3 sleep, Dell has seemingly rowed back on this promise. Responding to a question on Twitter about there being "hundreds of posts on various forums" about sleep issues with the XPS 15, Frank Azor stated: