Turn on optimizations for windowed games
Lets DirectX 10/11 games in windowed or borderless mode use flip-model presentation.
Applying it needs Nexus Standard or Pro. Every plan can read it here and undo it in Restore Center. Compare plans
What it changes
Sets SwapEffectUpgradeEnable=1 in HKCU\Software\Microsoft\DirectX\UserGpuPreferences\DirectXUserGlobalSettings (Settings > Display > Graphics > Optimizations for windowed games). Other options stored in the same value are preserved.
Before anything is written, the review screen shows this setting's current value on your PC next to the new one.
Why it helps
Microsoft states this lowers latency for windowed/borderless DX10/DX11 games and enables Auto HDR and variable refresh rate in windowed mode.
Trade-offs
A small number of older games can misbehave; Windows skips games that are known to be incompatible. Fully reversible.
Evidence
Strong evidence means: documented by microsoft or consistently measurable. Expected impact is noticeable (2 of 3): how much it can matter when this is actually the bottleneck on your PC, not a promised gain.
Is it in a pack?
Yes. It's in the Gaming performance pack, so that pack and Optimize everything include it. You can still untick it in the review screen.
How to undo
Switch the tweak off in Nexus, or open Restore Center and restore this change (or choose Undo last change). Nexus writes back the original value it recorded before applying, not a generic default, then reads it back to confirm.