A late-night lab bench for Samsung’s 34-inch curved QD-OLED gaming monitor. Walk around it, open it up, zoom from the whole panel to single quantum-dot subpixels, and run the experiments that explain what you’re looking at — then set it up, tune it, and look after it.
3440 × 1440 UWQHD 21:91800R curve175 Hz · Game Mode on0.03 ms GtG (spec)99% DCI-P3250 cd/m² typical SDR
Modelled in Blender from Samsung’s published dimensions — 813.6 × 522.3 × 192.8 mm with the stand, 1800R curve, 120 mm of height travel, −2° to +20° tilt. Orbit it, move the stand, explode the panel stack, and inspect the rear ports.
Why the “pivot” is only ±3°
Samsung’s spec table lists “Pivot −3° to +3°”. The product guide explains it as levelling: hold both side edges and rotate until the picture is straight. It is not portrait rotation.
Product Guide BN81-26123B · Samsung UK spec
No swivel joint
The stand has height and tilt but no swivel (Samsung DE datasheet: “Swivel —”). The swivel slider turns the whole monitor on the desk, which is what you’d do in real life.
Samsung DE datasheet
Modelling assumptions
Outer dimensions, curvature and stand ranges are Samsung’s. The rear bulge shape, port order, internal board layout and exact layer thicknesses are our approximations — Samsung publishes no teardown.
02 · Unboxing
948 × 185 × 456 mm of box. 11.8 kg.
Step through the box in the order you’ll meet things. Contents are from Samsung’s spec tables for each region.
03 · Set-up & calibration
From bench to calibrated in ten steps.
The physical steps follow Samsung’s product guide. The menu steps follow the e-Manual. Calibration tips are reviewers’ findings on the closely related G85SB, flagged as such.
04 · Connection guide
Which port, which cable, which refresh rate.
One DisplayPort 1.4, two HDMI 2.1 (HDMI 1 with ARC), a USB 3.0 hub and DC in. No USB-C, no headphone jack. Tap a port, pick your device and cable.
Samsung’s timing table (3440 × 1440 and key others)
Mode
DisplayPort
HDMI
Needs
3440 × 1440 @ 175 Hz
✓ + VRR
✓ + VRR
Game Mode On
3440 × 1440 @ 120 Hz
✓ + VRR
✓ + VRR
Game Mode On
3440 × 1440 @ 100 Hz
—
✓
HDMI only
3440 × 1440 @ 60 / 50 Hz
✓
✓
Optimum with Game Mode off
2560 × 1440 @ 175 / 120 Hz
✓
✓
16:9 content
1920 × 1080 @ 175 / 120 Hz
✓
✓
VRR listed at 175 / 120
3840 × 2160 @ 60 Hz (downscaled)
listed; port not specified
10-bit 4:4:4 needs Input Signal Plus
Source: G85SD Product Guide supported-resolution and VRR tables. Samsung does not state DSC use or HDMI FRL bandwidth.
05 · Experiments
Seven experiments. The light is calculated.
The heavier simulations — subpixel rendering, motion persistence, backlight bloom, tone mapping and pixel wear — run in a small C engine compiled to WebAssembly. Your browser does the maths frame by frame.
EXP 01
Powers of ten: screen → pixel → quantum dot
Zoom from the whole 3440 × 1440 panel down to a single pixel, then into its three emitters. Switch the light path to see that every subpixel starts as blue OLED light, and that the red and green ones get their colour from quantum dots. Drag to pan, scroll or pinch to zoom.
Blue in, red and green out
QD-OLED combines a blue OLED light source in every subpixel with red and green quantum-dot layers. Blue subpixels pass their light straight through; red and green wells convert it. That is why one emitter material serves all three colours.
PC Monitors fringing article; TFTCentral
Why text can fringe
The 34″ QD-OLED triad puts green above red and blue. Windows’ ClearType assumes vertical R-G-B stripes, so horizontal edges can pick up green or magenta fringes. At about 110 ppi you may notice it up close; it fades with distance.
PC Monitors; Digital Trends (G85SB)
What we simplified
Samsung doesn’t document this panel’s subpixel shapes; ours are rounded squares in the photographed triad arrangement. Pixel pitch is Samsung’s 0.2315 mm.
EXP 02
Perfect black vs. a backlight
A starfield, a moving orb and a subtitle, shown twice. Left: an LCD that filters a backlight. Right: QD-OLED, where each pixel is its own light source. Raise the exposure to see what your dark-adapted eye sees at night.
1,000,000 : 1
Samsung’s typical static contrast figure. Reviewers of the G85SB couldn’t measure its black level at all — effectively infinite contrast, including ANSI patterns.
Samsung UK spec; Tom’s Hardware (G85SB)
Blooming
Local-dimming LCDs light zones, not pixels. A small bright object lights its whole zone and bleeds into neighbours — the halo you see chasing the orb.
Room light
QD-OLED panels have no polariser, so reflected room light lifts black. The G85SD’s matte Glare Free film changes how this looks versus glossy panels; no lab has measured it on this model yet. The room-light slider is illustrative.
EXP 03
60 vs 144 vs 175 Hz
The same probe crosses the screen at the same speed; only the refresh rate changes. Because your eye tracks moving objects while each frame is held still, every frame smears across your retina — the pursuit camera calculates exactly how much.
Sample-and-hold
An OLED shows each frame for the whole refresh period. Smear width ≈ speed ÷ refresh rate: at 960 px/s that’s 16 px at 60 Hz and 5.5 px at 175 Hz.
Your screen is the limit
A web page can’t show more frames than your display draws. On a 60 Hz phone the three live lanes look alike beyond 60 Hz — the pursuit simulation is independent of your screen.
Strobing is hypothetical
The persistence slider shows how shortening each frame’s lit time would sharpen motion. Samsung doesn’t list a black-frame-insertion mode for the G85SD.
EXP 04
Response time & ghosting
A pixel is told to change from dark to bright. How long until the light actually arrives? Compare the OLED trace with an LCD, and push the LCD’s overdrive to see overshoot.
0.03 ms grey-to-grey
Samsung’s figure, “based on internal test conditions”. Tom’s Hardware saw no reason to doubt it on the G85SB and noted OLED needs no overdrive tuning.
Samsung UK spec; Tom’s Hardware
Leave Response Time on Standard
The menu offers Standard, Faster and Extreme; Samsung warns the faster modes can distort video. On an OLED the panel is already quicker than any frame.
LCD curves are illustrative
The LCD traces are typical shapes for comparison, not measurements of a specific monitor.
EXP 05
Curvature & field of view, from above
Top-down, to scale: your eye, the desk and the 1800R arc. Drag the eye or use the presets to see how much of your vision the screen fills and how squarely its edges face you.
What “1800R” means
The screen follows a circle of 1.8 m radius. Sit at 1.8 m and every point is equidistant; at a desk the edges still turn toward you.
Samsung’s posture advice
45–50 cm from eye to screen, looking slightly down. At that distance the 800 mm-wide arc spans roughly 82–85° of your horizontal view.
Product Guide
EXP 06
HDR tone mapping
The scene holds a 4,000-nit headlight and a sun near 10,000 nits. The panel can’t show that, so something must give. Compare clipping with static and scene-adaptive roll-off curves, and watch automatic brightness limiting as more of the screen gets bright. False colour shows the nits on each pixel.
HDR10, HDR10+, HDR10+ Gaming
The formats Samsung lists. In the menu: HDR Tone Mapping, Peak Brightness and Auto HDR Remastering under Expert Settings; HDR10+ GAMING and Game HDR (HGiG) under Game Picture Expert.
Samsung UK spec; e-Manual
Measured on the sibling
Digital Trends: ≈902 nits at 3%, 448 at 10%, 272 full-screen (G85SB). Tom’s Hardware: ≈446 nits flat, and HDR “Movie” mode tracked the PQ curve best.
Digital Trends; Tom’s Hardware
No official HDR peak
Samsung’s G85SD spec tables don’t state an HDR peak or a DisplayHDR True Black certification. “1000 nits” comes from secondary sources.
06 · Settings
The menu, fully clickable.
The G85SD runs Tizen, so its on-screen menu is a smart-TV style Settings app. This replica follows Samsung’s e-Manual. Try switching Game Mode off or Input Signal Plus off and watch what greys out.
Built from e-Manual BN81-27566B-650 (Tizen 9 generic Smart Monitor guide, Oct 2025) and the G85SD Product Guide. Many items are marked “may not be supported depending on the model”; we haven’t checked them on a unit. Option lists the manual doesn’t spell out are flagged as inferred. Click the screen, then use arrow keys.
07 · Gaming
Recipes for play.
Settings combinations for four situations, and where each one lives in the menu.
Frame-time budget
Frame times are 1000 ÷ Hz. OLED 0.03 ms is Samsung’s spec; the LCD bar is illustrative.
Game Bar
Hold Play/Pause on the remote in Game Mode. It shows resolution, frame rate, HDR and VRR status, and quick controls for game genre, Virtual Aim Point, screen ratio, minimap zoom and response time.
e-Manual
Measured latency
27 ms
Tom’s Hardware’s end-to-end “total lag” on the G85SB sibling. It isn’t comparable with RTINGS-style input-lag numbers, and nobody has published per-refresh figures for the G85SD.
Tom’s Hardware (G85SB)
08 · Everyday care
Burn-in, and what the care features actually do.
OLED subpixels lose a little brightness as they emit light. Static content ages its pixels faster than everything around it, and that uneven ageing is burn-in. Run the time-lapse, then switch the protections on.
EXP 07
Burn-in time-lapse
OLED Safeguard (G85SD)
Thermal Modulation System — predicts surface temperature and lowers brightness to cut heat.
Logo & Taskbar Detection — dims static logos and taskbars (logo detection isn’t available in PC mode).
Screen Saver — dims the screen when nothing changes.
Samsung UK / US product pages
Not the “+” version
OLED Safeguard+, with a pulsating heat pipe (“Dynamic Cooling System”), was announced for the 2024 G80SD and G60SD. It isn’t listed for the G85SD — the ghosted pipe in the exploded model shows what’s absent.
Samsung US Newsroom; G85SD spec pages
Panel Care menu
Picture › Panel Care › Adjust Logo Brightness (Off / Low / High) and Pixel Refresh. Pixel Refresh also runs automatically when you switch off after a long session; Samsung doesn’t state how long it takes or how often.
e-Manual p.144, p.128
Habits that help
Auto-hide the taskbar, prefer dark themes, rotate wallpapers.
Switch off with the remote, not at the wall, so Pixel Refresh can run.
Avoid hours of 16:9 or 4:3 content with bars on the 21:9 screen — Samsung lists this as an after-image risk.
e-Manual p.144
Cleaning
Switch off the monitor and PC; unplug the power.
Wipe with a clean, soft, dry cloth — or one dampened with water and wrung out.
No alcohol, solvents or surfactants. Never spray liquid onto the screen. Don’t press on the panel.
Product Guide, “Cleaning”
Warranty & burn-in
Samsung’s spec lines (UK, AU, CA, US): “Burn-in at normal usage covered within warranty”, excluding commercial use, abuse or misuse.
US: 3-year warranty (Samsung US product guide).
Germany: 2 years (DE datasheet).
UK/AU: duration not found in the sources we hold.
Samsung’s generic US monitor warranty card excludes burned-in images, which conflicts with the G85SD spec line — keep your proof of purchase and check the terms for your region.
Samsung spec pages; US warranty card 003
09 · Research ledger
Every figure, and how sure we are.
SAMSUNG stated in an official Samsung document. MEASURED measured by a reviewer. UNCONFIRMED conflicting, secondary or derived. No independent lab review of the G85SD itself had been published when we checked (30 Sep 2026); measurements elsewhere on this site are of the 2023 G85SB, which shares the 34″ 175 Hz QD-OLED spec but has a glossy screen and different ports.
Firmware
Samsung UK lists main firmware T-PTMLDWWC 1340.1 (21 Apr 2026) and OS upgrade 0090-2131.1 (15 Sep 2026; Tizen One UI 8.0 → 9.0 — new Gaming Hub UI, settings search, Self Diagnosis “Test All”, a PIN in initial set-up, irreversible). No changelog is published for 1340.1.
Samsung UK support; OS Upgrade Release Note 0090
Still open
QD-OLED panel generation
HDR peak and DisplayHDR certification
DSC and HDMI 2.1 bandwidth; native 10-bit at 175 Hz
Official NVIDIA G-SYNC Compatible status
Pixel Refresh timing; whether a Pixel Shift toggle exists
Screen Saver timing (10 min marketing vs 2 min e-Manual)
Stand base footprint and min/max height
Model codes
S34DG85*S family: LS34DG850SUXEN (EU), LS34DG850SUXXU (UK), LS34DG850SNXZA (US/CA), LS34DG856SNXZA (US variant), LS34DG850SEXXY (AU/NZ). Regional figures occasionally differ (e.g. typical power 42 W vs 45 W).