LG UltraFine 40U990A-W vs LG UltraGear 45GX950A 45"
Side-by-side comparison of viewing distance, PPI, and specifications
LG UltraGear 45GX950A 45"
44.5" · 5120×2160 · OLED
Optimal Viewing Distance 70cm
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Category Ranking
Pixel Density (PPI)67in category
LG UltraFine 40U990A-W140 PPI #30
LG UltraGear 45GX950A 45"125 PPI #44
93 PPI224 PPI
HDR Peak Brightness67in category
LG UltraFine 40U990A-W600 nits #22
LG UltraGear 45GX950A 45"1300 nits #3
250 nits2000 nits
DCI-P3 Color Gamut63in category
LG UltraFine 40U990A-W99% #2
LG UltraGear 45GX950A 45"98% #31
79%100%
Refresh Rate
LG UltraFine 40U990A-W120 Hz
LG UltraGear 45GX950A 45"165 Hz
StandardHighUltra
Summary
- Sharpness: advantage LG UltraFine 40U990A-W — At 65cm, the LG UltraFine 40U990A-W is retina (140 PPI) while the LG UltraGear 45GX950A 45" is not — you need to sit at least 70cm away for pixel-free viewing.
- Brightness: advantage LG UltraFine 40U990A-W — The LG UltraFine 40U990A-W is 64% brighter in SDR (450 vs 275 nits), a noticeable difference for outdoor readability. HDR peak: 600 vs 1300 nits.
Key Differences
| Specification | LG UltraFine 40U990A-W | LG UltraGear 45GX950A 45" |
|---|---|---|
| Pixel Density (PPI) | 140 | 125 |
| Optimal Viewing Distance | 62cm | 70cm |
| SDR Brightness | 450 nits | 275 nits |
| Color Gamut | sRGB 100% · DCI-P3 99% | sRGB 100% · DCI-P3 98% · Adobe RGB 94% |
| Screen Size | 39.7" | 44.5" |
| Refresh Rate | 120 Hz | 165 Hz |
| Response Time | 5 ms GTG | 0.0 ms GTG |
| HDR Peak Brightness | 600 nits | 1300 nits |
| Contrast Ratio | 1:2,000 | 1:1,500,000 |
All specifications
| Specification | LG UltraFine 40U990A-W 2025 | LG UltraGear 45GX950A 45" 2025 |
|---|---|---|
| Screen Size | 39.7" | 44.5" (Better) |
| Resolution | 5120×2160 | 5120×2160 |
| Pixel Density (PPI) | 140 (Better) | 125 |
| Optimal Viewing Distance | 62cm (Better) | 70cm |
| Panel Type | IPS | OLED |
| Viewing Angle | 178° | 178° |
| Aspect Ratio | 21:9 | 21:9 |
| Refresh Rate | 120 Hz | 165 Hz (Better) |
| Variable Refresh Rate (VRR) | FreeSync Premium | FreeSync Premium Pro |
| Response Time | 5 ms GTG | 0.0 ms GTG (Better) |
| HDR Certification | DisplayHDR 600 | DisplayHDR True Black 400 |
| SDR Brightness | 450 nits (Better) | 275 nits |
| HDR Peak Brightness | 600 nits | 1300 nits (Better) |
| Contrast Ratio | 1:2,000 | 1:1,500,000 (Better) |
| Ports | 2x HDMI · 1x DP · USB-C · USB Hub | 2x HDMI · 1x DP · USB-C · USB Hub |
| USB-C Power Delivery | — | 90 W |
| Color Gamut | sRGB 100% · DCI-P3 99% (Better) | sRGB 100% · DCI-P3 98% · Adobe RGB 94% |
| Year | 2025 | 2025 |
Frequently Asked Questions
Which has better PPI: LG UltraFine 40U990A-W or LG UltraGear 45GX950A 45"?
The LG UltraFine 40U990A-W has 140 PPI compared to 125 PPI for the LG UltraGear 45GX950A 45".
Which has a closer optimal viewing distance?
The LG UltraFine 40U990A-W requires 62cm vs 70cm for the LG UltraGear 45GX950A 45" to reach retina quality.
Related Comparisons
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vs LG UltraFine 40U990A-W 2025 · 140 PPI · 39.7" · 120 Hz
Alienware AW2725DF 27" 2024 · 110 PPI · 26.7" · 360 Hz
vs LG UltraGear 45GX950A 45" 2025 · 125 PPI · 44.5" · 165 Hz
Alienware AW3225QF 32" 2024 · 139 PPI · 31.6" · 240 Hz
vs LG UltraFine 40U990A-W 2025 · 140 PPI · 39.7" · 120 Hz
Alienware AW3225QF 32" 2024 · 139 PPI · 31.6" · 240 Hz
vs LG UltraGear 45GX950A 45" 2025 · 125 PPI · 44.5" · 165 Hz
Methodology & Sources
Formula: Retina distance (cm) = 3438 / PPI. Displayed values are rounded for readability.
Sources: Official manufacturer spec sheets and product pages. Specs are normalized before comparisons.
Comparison winners are calculated metric by metric (higher is better for most specs; lower is better for distance/response time).
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