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Kuycon P27D vs LG UltraFine 40U990A-W

Side-by-side comparison of viewing distance, PPI, and specifications

Kuycon P27D

27" · 3840×2160 · IPS
Optimal Viewing Distance 54cm
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LG UltraFine 40U990A-W

39.7" · 5120×2160 · IPS
Optimal Viewing Distance 62cm
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Category Ranking

Pixel Density (PPI)67in category
Kuycon P27D163 PPI #20
LG UltraFine 40U990A-W140 PPI #30
93 PPI224 PPI
HDR Peak Brightness67in category
Kuycon P27D500 nits #42
LG UltraFine 40U990A-W600 nits #22
250 nits2000 nits
DCI-P3 Color Gamut
LG UltraFine 40U990A-W99% #2
79%100%
Refresh Rate
Kuycon P27D144 Hz
LG UltraFine 40U990A-W120 Hz
StandardHighUltra

Summary

  • Sharpness: no visible difference — Both screens exceed the retina threshold at 65cm. The Kuycon P27D has 17% higher pixel density (163 vs 140 PPI), but this only becomes visible below 54cm.
  • Brightness: advantage LG UltraFine 40U990A-W — Similar SDR brightness (500 vs 450 nits), but the LG UltraFine 40U990A-W leads in HDR peak (600 vs 500 nits).

Key Differences

Specification Kuycon P27D LG UltraFine 40U990A-W
Pixel Density (PPI) 163 140
Optimal Viewing Distance 54cm 62cm
Refresh Rate 144 Hz 120 Hz
SDR Brightness 500 nits 450 nits
Screen Size 27" 39.7"
Resolution 3840×2160 5120×2160
HDR Peak Brightness 500 nits 600 nits
Contrast Ratio 1:1,000 1:2,000
Color Gamut sRGB 99% sRGB 100% · DCI-P3 99%
All specifications
Specification Kuycon P27D 2025 LG UltraFine 40U990A-W 2025
Screen Size 27" 39.7" (Better)
Resolution 3840×2160 5120×2160 (Better)
Pixel Density (PPI) 163 (Better) 140
Optimal Viewing Distance 54cm (Better) 62cm
Panel Type IPS IPS
Viewing Angle 178° 178°
Aspect Ratio 16:9 21:9
Refresh Rate 144 Hz (Better) 120 Hz
Variable Refresh Rate (VRR) G-SYNC Compatible FreeSync Premium
Response Time 5 ms GTG 5 ms GTG
HDR Certification None DisplayHDR 600
SDR Brightness 500 nits (Better) 450 nits
HDR Peak Brightness 500 nits 600 nits (Better)
Contrast Ratio 1:1,000 1:2,000 (Better)
Ports 2x HDMI · 1x DP · USB-C · USB Hub 2x HDMI · 1x DP · USB-C · USB Hub
USB-C Power Delivery 100 W
Color Gamut sRGB 99% sRGB 100% · DCI-P3 99% (Better)
Year 2025 2025

Frequently Asked Questions

Which has better PPI: Kuycon P27D or LG UltraFine 40U990A-W?
The Kuycon P27D has 163 PPI compared to 140 PPI for the LG UltraFine 40U990A-W.
Which has a closer optimal viewing distance?
The Kuycon P27D requires 54cm vs 62cm for the LG UltraFine 40U990A-W to reach retina quality.
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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