What refresh rate should your capture card run at?

Should my capture card run at 120 Hz or 144 Hz?

120 Hz: for a 60 fps stream, the card’s refresh rate should be a whole multiple of 60, and 144 isn’t one. Three rules settle it for any card:

1. A whole multiple of your stream’s frame rate. At 60, 120 or 240 Hz, every stream frame lasts the same number of refreshes. At 144 or 165 Hz, some last 2 and some 3, and motion judders.
2. The fastest one your card really captures. Cards accept faster signals than they capture. Go by what the card captures at the resolution you stream, not the fastest signal it takes.
3. Exact rates. 60, 120 and 240 Hz, not 59.94 or 119.88. Against a 60 fps stream, 59.94 slips a whole frame every 16.7 seconds.

At 1080p, the fastest cards capture 240 fps, so they run at 240 Hz. At 1440p, they capture 144 fps, and the fastest whole multiple of 60 within that is 120 Hz.

Why does 144 Hz judder on a 60 fps stream?

Because 144 doesn’t divide evenly by 60: some stream frames last 2 of the card’s refreshes and some last 3, so motion moves on in uneven steps.

OBS takes one frame from the card for each frame of your stream, 60 times a second. At 120 Hz that’s every 2nd refresh and at 240 Hz every 4th, always the same. At 144 Hz there are 2.4 refreshes per stream frame, so OBS takes them in a repeating 2, 2, 3, 2, 3 pattern. The game moves on 13.9 ms in some stream frames and 20.8 ms in others, instead of a steady 16.7 ms, and it shows most on smooth camera pans.

It isn’t a performance problem, so faster hardware doesn’t fix it: the pattern is arithmetic, and it repeats for as long as the card runs at that rate. 100 and 165 Hz do the same. In a simulation of how OBS picks frames, with both PCs’ clocks perfectly in step:

Uneven frames are the ones that land at least half a refresh off the steady 16.7 ms. Age is how long the frame OBS takes has been waiting, on average: even rates above 60 don’t change the motion, they make the picture fresher.

A 30 fps stream follows the same rule with multiples of 30. 60, 120 and 240 Hz divide evenly into it, at 2, 4 and 8 refreshes per stream frame, and 144 and 165 Hz still don’t.

Is 240 Hz passthrough the same as 240 Hz capture?

No: most capture cards accept faster signals than they capture, and anything above the capture limit only reaches the card’s HDMI OUT, its passthrough to a monitor. OBS gets a slower copy, so the faster signal gives your stream nothing.

The card drops the extra refreshes itself, before OBS sees them. The Elgato HD60 X takes a 1080p240 signal but captures 1080p at 120 fps at most. The Elgato HD60 S+ captures 60 fps at most. Even the Elgato 4K X only passes 1440p240 through: it captures 1440p at 144 fps.

Some fast modes do reach OBS, but only as MJPEG: compressed video that the streaming PC’s processor has to decode, with compression artefacts. The Elgato 4K S sends 1080p240 only that way, and captures 1080p at 120 fps uncompressed. The Elgato 4K X sends 2160p at 120 or 144 only as MJPEG, and captures 2160p at 60 fps uncompressed. Count an MJPEG-only mode as one the card doesn’t capture.

In the maker’s specifications, look for the capture resolutions and frame rates, not the passthrough ones, or find your card in the next section.

What’s the best refresh rate for my capture card?

For a 60 fps stream, the fastest whole multiple of 60 it captures uncompressed at your stream’s resolution: 240 Hz for an Elgato 4K X at 1080p, 120 Hz for an Elgato HD60 X. For a few common cards, “fastest” is the most each one captures and “best” is the refresh to run it at:

A dash means the card can’t capture that size for a 60 fps stream.

Notes on these cards

• Elgato 4K X. Needs a 10 Gbps USB port for 1080p240 and 1440p144; on 5 Gbps it captures 1080p120, 1440p60 and 2160p30. 1440p240 is passthrough only.
• Elgato 4K60 Pro MK.2. HDMI 2.0: 1080p240 and 1440p144 fit only with 8-bit colour.
• Elgato HD60 X. 1080p240 and 1440p120 are passthrough only.
• Elgato 4K S. Fixed EDID. 1080p240, 1440p120 and 2160p60 reach OBS only as MJPEG, so Anti Tear never picks them.
• Elgato HD60 S+. Captures 60 fps at most; anything faster is passthrough only.
• AVerMedia Live Gamer 4K 2.1 (GC575). HDMI 2.0 mode in Assist Central Pro is enough for 1080p240 and 1440p144.
• AVerMedia Live Gamer Ultra (GC553). Fixed EDID. 1080p240 and 1440p144 are passthrough only.

If Windows doesn’t offer a mode your card captures, its EDID may be hiding it. The EDID is the list of modes a display tells the PC it accepts. Some cards let you change theirs in the maker’s software; a fixed EDID can’t be changed. How to unlock 240 Hz and 144 Hz

Does 240 Hz make a 60 fps stream smoother?

Not in steady motion: a 60 fps stream at 120 or 240 Hz shows the same 60 evenly spaced frames a second as at 60 Hz. What a faster even rate buys is smaller hitches and fresher frames, and it costs the streaming PC more work.

Smaller hitches

The gaming PC times the card and the streaming PC times OBS, and two PCs’ clocks never run at exactly the same speed. A difference of 20 to 100 parts per million is normal, so now and then OBS has to drop or repeat a frame to catch up. At 60 Hz that’s a whole 16.7 ms frame, about every 5.5 minutes at 50 parts per million. At 240 Hz the same drift comes out as a 4.2 ms slip 4 times as often: 4× smaller, and much milder. No OBS setting removes it, because it comes from the clocks, not from OBS.

Fresher frames

At 240 Hz the frame OBS takes has waited 2.1 ms on average, against 8.3 ms at 60 Hz, so each stream frame is about 6 ms fresher.

More work for the streaming PC

Compared with 60 Hz, twice as much video arrives at 120 Hz and 4 times as much at 240 Hz: uncompressed 1080p at 240 fps is about 746 MB a second. Frames also have to arrive on time. At 60 Hz a frame can be about 8 ms late without harm, but at 240 Hz the newest frame lands only about 2 ms before OBS takes it. With OBS’s Buffering off, 3 ms of USB or driver delay is enough to make frames uneven again. Setting it to Enable fixes that, as the OBS settings below explain.

If your streaming PC struggles at 240, 120 is just as even, with half the work.

Tearing

If the capture tears, because the game runs with vsync off and the card copies it, a faster rate means fewer tear lines per captured frame, not none: about 5 at 60 Hz for a 300 fps game, 1 or 2 at 240 Hz.

Why does my stream hitch every 16 or 17 seconds?

Because one side runs at 59.94 and the other at 60: they drift a whole frame apart every 16.7 seconds, and OBS drops or repeats a frame to catch up.

59.94 is 60 slowed by 1 part in 1,000. It sits next to 60 in OBS’s frame rate lists, and capture cards can offer both. Mix the two anywhere, a 59.94 Hz card into a 60 fps canvas or a 60 Hz card into a 59.94 fps one, and the stream hitches on a steady beat. A faster card doesn’t cure it: at 240 Hz into a 59.94 canvas, the slips shrink to a quarter of a frame but come about every 4 seconds.

Use exact rates on both PCs: 60, 120 or 240 Hz on the card, and a whole 60 fps canvas in OBS. Some tools set a refresh rate as a whole number, and asking for 60 that way can land on 59.94. Exact rates leave only the small drift between the two clocks: a hitch every few minutes, which 240 Hz makes 4× smaller.

What should I set in OBS for a 240 Hz capture card?

For a card at 240 Hz, set the Video Capture Device’s FPS to 240 and its Buffering to Enable, and keep OBS’s canvas, your stream’s own frame rate, at a whole 60 fps. The full list:

1. 1OBS frame rate: 240Video Capture Device › Properties › FPS. The same rate the capture card runs at.
2. 2Buffering: EnableVideo Capture Device › Properties. “Auto” leaves it off for cards that send raw video, and above 60 fps it needs Enable.
3. 3Canvas: a whole 60 fpsSettings › Video. 60, not 59.94, or the stream hitches every 16.7 s.
4. 4Video format: NV12Video Capture Device › Properties. Avoid MJPEG modes.
5. 5Color range: FullVideo Capture Device › Properties. Must match the GPU output.
6. 6Audio: 48 kHzSettings › Audio. Matches the card.

Frame rate. The FPS in the source’s properties is how fast OBS reads the card, so it matches the card’s refresh: 240 here, or 120 for a card at 120 Hz. Set Resolution/FPS Type to Custom to choose it. OBS has listed 240, 144 and 120 there since version 29; on older versions, choose Highest FPS. The canvas in Settings › Video stays at 60, and OBS takes one of every 4 card frames.

Buffering. On Auto, OBS leaves buffering off for cards that send uncompressed video, and simply shows the newest frame that has arrived. That’s fine at 60 Hz. Above 60, small USB and driver delays can make frames uneven, and Enable fixes it: OBS paces frames by when each one arrived, at the cost of a little delay. In one streamer’s 30-minute test, Buffering off gave 1,512 repeated frames, and Enable gave 96 dropped ones. The OBS knowledge base covers the source’s other settings.

The rest keeps the picture right: NV12 is uncompressed, Color range has to match what the gaming PC’s graphics card sends, and 48 kHz audio keeps the sound from drifting.

Can Anti Tear set the refresh rate for me?

Yes. Anti Tear knows what each of 24 capture cards really captures, and runs yours at the fastest refresh it captures that divides evenly into your stream’s frame rate. It sets exact rates like 60, 120 and 240 Hz, never 59.94, skips modes that reach OBS only as MJPEG, and runs a card it doesn’t know at 60 Hz.

A new mode is a 15-second trial: keep it if OBS shows a picture, or do nothing and it goes back by itself. Anti Tear then puts your game on the card and changes frames only in its vblank, the short pause between two refreshes, so the capture can’t tear. Its Smooth mode keeps one frame in reserve, for one refresh more delay, to even out the occasional clock-drift hitch, and its Output page shows the OBS settings above with your card’s numbers.