Nvidia's New GeForce Driver Claims to Fix DPC Latency Issues
Nvidia has just released a new Game Ready driver, headlined as delivering support for a few new games. Specifically, there's Portal: Prelude RTX, which has RTX IO support (a variant of DirectStorage that we're told works on non-Nvidia GPUs as well), and Ratchet & Clank: Rift Apart, which also has RTX IO suport. Alongside the games, this is also the first driver with support for the GeForce RTX 4060 Ti 16GB custom cards from AIBs. However, you have to dig through the release notes (PDF) to find out that this is the long-awaited driver release which finally addresses DPC latency.
Last month we reported that Nvidia's software quality assurance spokesperson Manuel Guzman signaled a DPC latency fix had been developed and that it was just going through QA before it could be rolled out. Deferred Procedure Calls (DPC) in Windows were designed for high-priority tasks to defer required but lower-priority tasks for later execution. If a driver's DPC routines aren't written correctly, the user can see symptoms manifest as stutters, skips, and similar glitches in video and audio. Users who aren't sure if they are affected can run the Latencymon tool, to check their numbers; smaller values are better.
In Nvidia's 536.67 WHQL drivers, the release notes say that it fixed two bugs, one where applying Freestyle filters caused games to crash, and another one to address DPC latency. As you can see in the screenshot, we don't get a lot of information from Nvidia about the fix, only that using the new driver should eradicate the "Increase in DPC latency observed in Latencymon for Ampere-based GPUs [3952556]." That reference number points back to the raising of this issue among the 'Known Issues' last year.
Last month we pointed out that the value of Nvidia's fix can only be demonstrated by a mass of users testing and being happy with it. Signs so far (just a few hours after release) aren't 100% positive. We note that Manuel Guzman has been chatting with two users who don't feel the benefit of the new driver. At the time of writing, it looks like more independent testing needs to be done to verify the fix, and perhaps more work to truly fix the root cause may be needed.
Nvidia 536.67 Driver Notes
In this driver, Nvidia says that the following new games are now optimized for GeForce users:
Portal: Prelude RTX, a free, fully ray traced Portal mod with path-traced graphics, DLSS 3, Reflex, and RTX IO
Ratchet & Clank: Rift Apart with DLSS 3, advanced ray tracing, Reflex, and RTX IO
Remnant II from Gunfire Games has DLSS 2
Additionally, a trio of new G-Sync Compatible displays has been validated, including the very tasty 48-inch Panasonic 48MZ1800 OLED 4K monitor. Seven new games have GeForce Experience Optimal Settings configurations, including BattleBit Remastered.
Last but not least, the new driver supports the new 16GB models of the GeForce RTX 4060 Ti from Nvidia AIBs. You can read more about this new driver via the official release notes or GeForce blog (linked top), and actual driver downloads can be grabbed via the GeForce site, or alternatively use GeForce Experience to auto-download and apply this new driver.
