By "VSYNC with a 3rd party application":jorimt wrote: ↑29 Jul 2020, 07:21I'm not sure I follow? RTSS is an FPS limiter, not a syncing method, so it won't prevent tearing.
If, however, you're referring to RTSS Scanline Sync, then it won't work in conjunction with G-SYNC, as it's effectively trying to do the same thing, but at a fixed refresh rate (tearline steering into the VBLANK).
RTSS is indeed normally a framerate limiter. That said the boundary between frame rate limiters and sync methods can get somewhat blurry with RTSS Scanline Sync.
However, RTSS Scanline Sync is essentially a software-based VSYNC method (i.e. creates a new better VSYNC ON technique that the drivers doesn't implement directly). It is designed to work properly with fixed-Hz displays, as a "low-lag VSYNC ON equivalent", but Scanline Sync can be hard to set up and tune -- it works most reliably during framerate=Hz at low GPU utilization. However, Scanline Sync and strobing can be a marriage made in heaven (ULMB, DyAc, etc), producing among the lowest strobed latencies possible with stutterless/jitterless motion ("TestUFO smooth & clear" panning/scrolling/strafing/turning motions), provided you're willing to tune the framerate and refreshrates to match. It is done by simulating VSYNC ON via VSYNC OFF, and steering the tearlines between refresh cycles (tearline just below bottom edge or above top edge).
However, RTSS Scanline Sync doesn't have any major advantages over ingame-capped VRR, but RTSS Scanline Sync does wonders when you can't use capped VRR (e.g. monitors without VRR, or when you're using a strobe mode such as ULMB/DyAc/etc).
For CS:GO on a VRR monitor, RTSS Scanline Sync isn't nearly as useful, unless your gaming tactics benefits from motion blur reduction (HOWTO: Using ULMB Beautifully or Competitively). Most CS:GO players won't benefit as much from strobing, but other gaming genres will benefit way more (especially games without crosshairs, and has lots of panning/scrolling motions)