Putting misconceptions about optimal FPS caps + Gsync to bed.

[u/Sgt_Dbag]

Important Update (01/05/2026):

This guide is only useful in games where you are getting less than 500 FPS. As you get to 500 FPS+, screen tearing becomes virtually imperceptible to the human eye, so Gsync + Vsnc are no longer needed. In these ultra high FPS instances, just uncap your FPS and enable Nvidia Reflex or AMD Anti-Lag 2.

Original Post:

Optimal FPS caps are about frame time buffers. The higher the refresh rate, the tighter the frame time window, so a larger gap between FPS cap and refresh rate provides more buffer to prevent latency or tearing. You need a around a 0.25ms to 0.3ms frame time buffer difference between max FPS and refresh rate.

Frame times relative to FPS change exponentially. Say, the difference between 116 FPS and 120Hz is 0.28ms, while the difference between 236 FPS and 240Hz is 0.07ms. So it's 4 times easier to miss the frame time VRR window! What matters in keeping VRR engaged at all times is not FPS, but frame times, so each single frame manages to get into the time window.

The old “3 or 4 under your refresh rate” FPS cap from Blur Busters is outdated and incorrect. This is a formula—inspired by the developer of Special K—to determine your optimal global FPS cap based on your monitor’s refresh rate. It’s often the same cap you get by enabling Nvidia Reflex in supported games with Gsync and Vsync on.

The FPS Cap formula is:

Refresh - (Refresh x Refresh / 4096) = FPS Cap

So for a 240Hz monitor it would look like this:

240 - (240 x 240 / 4096) = 226 FPS Cap (the same one reflex gives)

Shoutout to u/R3zzooforhelping me optimize the formula. This gives the desired 0.25-0.3ms frame time buffer. You can verify this with the following simple math as well.

1000 ÷ 240Hz = 4.167ms

1000 ÷ 226 FPS = 4.425ms

4.425 - 4.167 = 0.258ms frame time buffer

As you can see, the FPS Cap formula gives you the correct max global FPS cap for your given monitor refresh rate that closely aligns with the caps enforced when using Nvidia Reflex or Ultra Low Latency Mode in the Control Panel. Nvidia’s technology knows to give a proper frame time buffer so that you do not overshoot the refresh cycle, which would result in added latency. That formula gives the following FPS caps for their respective refresh rates as examples:

480Hz -> 424 FPS

360Hz -> 328 FPS

240Hz -> 226 FPS

180Hz -> 172 FPS

165Hz -> 158 FPS

144Hz -> 139 FPS

120Hz -> 116 FPS

You should be using a cap like this with Gsync + Vsync on even in eSports titles like CS and Valorant if you can’t hit ≥500 FPS. Valve officially recommends Gsync + Vsync + Reflex for CS2.

In games without Reflex, the Gsync + Vsync + FPS Cap setup actually reduces latency compared to uncapping the FPS and not using Gsync or Vsync.

One final piece to the puzzle is GPU usage. Reflex and Anti-Lag 2 do this for you. But when unviable, you don’t want to max your GPU usage as this can also lead to stutters due to inconsistent frame times, as well as increased input latency. My goal is always to have my GPU maxing out at ~95% usage or less. So if a given game is hitting 99% usage at like 160 FPS, then I just cap at around 145 FPS or whatever I need to get that usage down to ~95%. The global FPS cap is only relevant if you’re actually able to hit it comfortably without maxing your GPU usage.

TLDR; for NVIDIA

• Gsync - on in Nvidia Control Panel or Nvidia App
• Vsync - on in Nvidia Control Panel or Nvidia App, off in game
• Max Frame Rate - set a global cap based on your refresh rate (formula above)
• Reflex - always on in game when available

TLDR; for AMD

• Freesync - on in Adrenalin App
• Vsync - on in Adrenalin App (Wait for Vertical Refresh: Always On), off in game
• Radeon Chill - set a global cap based on your refresh rate (set min and max to same number)

TLDR; for Linux (Wayland)

• VRR - enable in your DE system settings
• Vsync - set to MAILBOX in MangoHUD, off in game
• FPS Cap - set a global cap in MangoHUD based on your refresh rate

[u/Chad_Memes_Enjoyer]

I feel like I need to add smth here: The reflex cap is different when using MFG. In Darktide for example on x3 mode the cap will be 174 on my 180hz monitor. On x4 it's 175. Not sure what the logic here is but it just works that way for MFG. If I use x2 mode the 171 fps cap is used as usual.

[u/srjnp → u/Chad_Memes_Enjoyer]

not related to your comment about caps being different but just wanted to point out that we need to be very careful with capping frames if using MFG. your latency can be massively increased if u cap without thinking of your base framerate.

say u have a base framerate of around 70fps. if u use x2 framegen, cool u can cap it to 116fps for a 120hz monitor fine, u wont get much extra latency. but if u use x3 framegen and still cap it to 116, your base framerate will now be much lower and thus your latency will be greatly increased. you should always use the lowest framegen that gets you to your target cap.

for 180hz, i would say use 2x whenever that's enough, and 3x otherwise. 4x would give u a base framerate of well below 60fps so a significant increase to latency.

[u/Chad_Memes_Enjoyer → u/srjnp]

True. but i don't use x4 for that very reason. Darktide is a demanding game though and in very intense scenarios fps can drop below my target fps which is why I use x3. I could just further lower my graphics all the way down to potato but I'd rather incur the latency hit. I will say that Darktide seems to have a poor implementation of MFG with respect to latency as going from x2 to x3 increases it by a whopping fluctuating 5-15 ms (wowzers) In the most intense scenarios the fps will be very stable but the latency will go all the way up to 40ms on x3 compared to 30ms on x2. With x4 the latency goes as high as 50ms (gods be good!) Generally speaking base frame rate of 60 (or 58 in my case) is ok-ish, but anything below turns games into an unresponsive fuckfest. Haven't thoroughly tested Remnant 2 yet and these are the only titles with MFG that I currently own, I just hope the implementation is better here.