XPS 15 7590: No DPC latency issues, but 75 °C throttling and no S3 sleep.
It has been just under two weeks since Dell released the XPS 15 7590, and the internet is still awash with "unboxing and first look" reviews. As we pointed out a few days ago, this early coverage is often limited in its analysis, with reviewers often not having spent enough time with a device for it to reveal its idiosyncrasies. The XPS 15 9570, for instance, suffered from numerous problems that did reared their heads after early reviews had been concluded.
However, several threads on Reddit have revealed some more obtuse details about the XPS 15 7590 that may have some Dell fans frothing at the mouth. The threads are all about the Core i7-9750H model, although one has the 1080p IPS panel with the other having the new 4K OLED panel. One Redditor, who posts as u/Redundantt16, has uploaded information about DPC latency times for the XPS 15 7590, which were a bugbear of XPS 15 9570 owners. As the LatencyMon screenshot below shows, the XPS 15 7590 does not suffer from high latency times, nor is ACPI.sys a problem as it continues to be for the XPS 15 9570.
Great news, right? Well, another XPS 15 7590 owner, u/delyarb, has reported that their systems throttles at 75 °C, the same level that Dell reduced the XPS 15 9570 to following a BIOS update. However, u/Redundantt16 claims that their system throttles at 78 °C, which is an odd discrepancy. The latter would allow the system to maintain higher clock speeds, although even the latter is a way of maximum operating temperatures, which tend to be just shy of 100 °C. Worse still, Dell has not included the option to enable S3 sleep in the BIOS, as it originally did with the XPS 15 9570.
In short, it seems that Dell has resolved some of the issues that the XPS 15 9570 had while carrying over a few to its successor too. So XPS fans, it looks like you must put up with Disconnected Modern Standby and 75 °C throttling regardless of whether you purchase the XPS 15 7590 or its predecessor.