Alongside the GeForce GTX 1660 SUPER, NVIDIA is releasing the GeForce Software Branch 440 WHQL drivers, which introduce three big feature additions to Turing (GTX 16-series and RTX 20-series). These include updates to NVIDIA Ultra-Low Latency (NULL) input latency enhancement, ReShade implementation in FreeStyle, and improved Image Sharpening.
NULL (NVIDIA Ultra-Low Latency) is an input latency enhancement that seeks to reduce the time it takes for your input to register as an action in your game. With the GeForce 440 drivers, NVIDIA is introducing NVIDIA G-SYNC support to NULL, which means you benefit from the anti-tearing and smooth motion characteristics of G-SYNC while retaining the advantages of low input latency.
NVIDIA's own input latency testing shows that V-Sync On + G-SYNC + NULL (green bar) now offers comparable input latency to a scenario where V-SYNC, NULL, and G-SYNC are all disabled (dark green bar). The latter gives you the best latency, but leaves you with screen tearing.
Conventional V-Sync without NULL or G-SYNC is the worst scenario as the machine faces the highest input latency. NVIDIA's changes now let you have G-SYNC at the same low-input latencies as V-Sync off, "nullifying" G-SYNC's impact on input latency.
ReShade is an extremely popular 3D graphics post-processing software that lets you dramatically alter or improve a 3D scene or an image by running the final output through custom shaders called filters (similar to the "filters" in your phone's camera). ReShade enjoys a vast community of users with custom filters. NVIDIA Freestyle achieves pretty much the same thing (shader replacement and post-processing), which had NVIDIA introduce support for ReShade filters not just to Freestyle, but Ansel, the in-game still-art tool.
Custom shaders can be used to cheat competitive games, so the new support comes with some restrictions. Competitive games will let you use the 14 original Freestyle filters and over 30 official ReShade filters, but no custom filters. For non-competitive games (think AAA games with a focus on SP), you can choose from a broader selection of official ReShade filters in addition to the Freestyle filters (over 70 of them), and use custom ReShade filters. Ansel is far less restricted because it has little to do with competitive gaming. You can use any custom ReShade filter on games that support the Ansel SDK: 70+ official ReShade filters and 16 original Ansel filters.
NVIDIA made improvements to its Image Sharpening feature that lets you restore some detail in your images and play with settings such as resolution-scale or texture quality to vastly improve your frame rates. With the R440 drivers, NVIDIA reduced the performance cost of Image Sharpening. It's also supported on DirectX 9, DirectX 11, and DirectX 12. Support for DirectX 11 is significant as it's still a very popular 3D graphics API and many modern games use it, and AMD's competing Radeon Image Sharpening (RIS) still doesn't support DirectX 11 at the time of writing. NVIDIA also added Image Sharpening toggles to their Control Panel, so you can toggle the feature globally or game-specifically without GeForce Experience.