QMS-VRR Quick Media Switching (QMS), also called QMS-VRR

What QMS-VRR is

When a streaming box moves from a 60Hz home screen to a 24 fps movie, the HDMI link normally has to change timing, and the TV drops the picture while it resyncs. HDMI Licensing Administrator's own QMS page cites a 1 to 3 second blackout when a new video starts. Quick Media Switching, which HDMI describes as eliminating the delay that can result in blank screens before content is displayed, uses the HDMI VRR mechanism to eliminate the blackout period when a source switches its video mode. HDMI's page says it allows instant changes from 24Hz to 60Hz frame rate and anywhere in between, citing 24Hz, 50Hz, and 60Hz as examples. It sits in the HDMI 2.1 family: HDMI's page introduces it as an HDMI 2.1 feature, though its body text and navigation also place it under 2.2, so check the exact HDMI release when a spec sheet names one.

Without QMS, HDMI says the source has two bad choices when frame rate and refresh rate do not match. It can repeat frames, which introduces motion judder, or it can resync the clock, which causes an audio and video blackout. QMS gives a third path: keep the link running and tell the display what is coming.

How QMS works

Synopsys, which sells HDMI IP, explains the mechanism. QMS builds on VRR, so the display can adjust its refresh rate to match the changing frame rate instead of re-locking. The source announces the next frame rate in advance, so the display can perform frame rate conversions ahead of time. The source passes that information using Video Timing Extended Metadata (VTEM). It can also signal that the frame rate will stay constant for a long period, which lets the display apply higher-quality video processing. Frame rate is the number of frames the source generates per second. Refresh rate is how often the display updates, and modern TVs commonly offer 60Hz or 120Hz. QMS makes the display follow the first without a re-sync.

Synopsys also lists the limits. QMS increases latency, so it is not intended for gaming, where a constant frame rate may last only a frame or two. Both the source and the display must support it, and support can be added to existing devices through a firmware update. Synopsys dates HDMI 2.1a to 2022. The related Fixed Rate Link transport is covered under Fixed Rate Link.

QMS-VRR vs plain VRR and Match Frame Rate

VRR for gaming and QMS-VRR use the same mechanism for opposite purposes. Gaming VRR lets the TV follow a game's changing frame rate frame by frame. QMS uses it to jump between fixed rates (23.976, 24, 50, 60, 120Hz) cleanly. hifi.de states that the TV must support VRR as the technical basis for QMS, but support for VRR alone does not tell you QMS is present, since both ends must implement the QMS signaling.

QMS also changes how you should treat Match Frame Rate. Matching gets 24 fps film out at 24Hz so 3:2 pulldown judder goes away, but the price is the blackout at each switch. With QMS the match is free. If your box and TV both support it, you get even frame timing and no black screen. Ten switches during an evening of mixed browsing and viewing would cost 10 to 30 seconds of black at HDMI's 1 to 3 seconds, and QMS reduces that to nearly nothing.

What QMS does not remove

The constraint that matters most is that nothing else in the signal can change. HDMI's page states the condition: as long as the resolution remains the same and only the frame rate changes. AVCesar's report on the Apple TV launch says the switch is instant only if resolution, color, and HDR stay the same, so a jump from a 4K source to a 1080p one does not qualify. MacRumors adds that QMS VRR does not prevent blackouts when switching color spaces or HDR content, and hifi.de notes that a switch between SDR, HDR10, and Dolby Vision still produces a black screen. In practice many real switches change dynamic range as well as frame rate, which is why hifi.de calls the benefit limited. The Apple TV's separate Match Dynamic Range setting still blanks the screen when it flips.

Which devices support it

The Apple TV 4K was the first widely available source. MacRumors reported on November 2, 2022 that Apple would add QMS VRR to the new Apple TV 4K through a software update, and AVCesar reported it available on March 24, 2023, under Settings, Match Content, with 23.976, 24, 50, 60, and 120Hz supported. hifi.de calls the Apple TV 4K (2022 model year and later) the only widely available streaming player with QMS. MacRumors says the second-generation (2021) model would not get it, citing a YouTuber. Apple has not said whether older models will, AVCesar noted.

On the TV side, LG moved first. AVCesar says that at CES 2023 LG stated some of its OLED models (B3, C3, G3, M3, and Z3) and 2023 QNED81, QNED82, and QNED86 LCD models would support it, and hifi.de names the OLED C3 as among the first and lists the OLED G4, OLED C4, and selected QNED mini-LED sets as successors. What Hi-Fi reported that Samsung added QMS by firmware to two flagship QD-OLED TVs; its headline does not name the models and I could not load the article body. I could not verify QMS status for 2025 and 2026 TVs from any loaded source, so confirm it on the spec sheet or in the TV's HDMI settings before buying for it. AV receivers are the weak link: hifi.de says many were marketed with QMS but do not support it under HDMI 2.1a, with the first AVR chips for QMS-VRR expected from 2026, and the whole chain must support it. Cable choice follows the HDMI 2.1 ladder in HDMI 2.1, and the HDMI cable guide covers what each tier needs.