ASUS ROG Strix XG27JCG vs LG UltraFine 40U990A-W
Side-by-side comparison of viewing distance, PPI, and specifications
Category Ranking
Pixel Density (PPI)67in category
ASUS ROG Strix XG27JCG218 PPI #5
LG UltraFine 40U990A-W140 PPI #30
93 PPI224 PPI
HDR Peak Brightness67in category
ASUS ROG Strix XG27JCG600 nits #22
LG UltraFine 40U990A-W600 nits #22
250 nits2000 nits
DCI-P3 Color Gamut63in category
ASUS ROG Strix XG27JCG97% #44
LG UltraFine 40U990A-W99% #2
79%100%
Refresh Rate
ASUS ROG Strix XG27JCG180 Hz
LG UltraFine 40U990A-W120 Hz
StandardHighUltra
Summary
- Sharpness: no visible difference — Both screens exceed the retina threshold at 65cm. The ASUS ROG Strix XG27JCG has 55% higher pixel density (218 vs 140 PPI), but this only becomes visible below 40cm.
- Brightness: advantage LG UltraFine 40U990A-W — The LG UltraFine 40U990A-W is 29% brighter in SDR (450 vs 350 nits), a noticeable difference for outdoor readability. HDR peak: 600 vs 600 nits.
Key Differences
| Specification | ASUS ROG Strix XG27JCG | LG UltraFine 40U990A-W |
|---|---|---|
| Resolution | 5120×2880 | 5120×2160 |
| Pixel Density (PPI) | 218 | 140 |
| Optimal Viewing Distance | 40cm | 62cm |
| Refresh Rate | 180 Hz | 120 Hz |
| Response Time | 1 ms GTG | 5 ms GTG |
| Year | 2026 | 2025 |
| Screen Size | 27" | 39.7" |
| SDR Brightness | 350 nits | 450 nits |
| Contrast Ratio | 1:1,500 | 1:2,000 |
| Color Gamut | sRGB 100% · DCI-P3 97% | sRGB 100% · DCI-P3 99% |
All specifications
| Specification | ASUS ROG Strix XG27JCG 2026 | LG UltraFine 40U990A-W 2025 |
|---|---|---|
| Screen Size | 27" | 39.7" (Better) |
| Resolution | 5120×2880 (Better) | 5120×2160 |
| Pixel Density (PPI) | 218 (Better) | 140 |
| Optimal Viewing Distance | 40cm (Better) | 62cm |
| Panel Type | IPS | IPS |
| Viewing Angle | 178° | 178° |
| Aspect Ratio | 16:9 | 21:9 |
| Refresh Rate | 180 Hz (Better) | 120 Hz |
| Variable Refresh Rate (VRR) | FreeSync Premium Pro | FreeSync Premium |
| Response Time | 1 ms GTG (Better) | 5 ms GTG |
| HDR Certification | DisplayHDR 600 | DisplayHDR 600 |
| SDR Brightness | 350 nits | 450 nits (Better) |
| HDR Peak Brightness | 600 nits | 600 nits |
| Contrast Ratio | 1:1,500 | 1:2,000 (Better) |
| Ports | 2x HDMI · 1x DP · USB-C · USB Hub | 2x HDMI · 1x DP · USB-C · USB Hub |
| Color Gamut | sRGB 100% · DCI-P3 97% | sRGB 100% · DCI-P3 99% (Better) |
| Year | 2026 (Better) | 2025 |
Frequently Asked Questions
Which has better PPI: ASUS ROG Strix XG27JCG or LG UltraFine 40U990A-W?
The ASUS ROG Strix XG27JCG has 218 PPI compared to 140 PPI for the LG UltraFine 40U990A-W.
Which has a closer optimal viewing distance?
The ASUS ROG Strix XG27JCG requires 40cm vs 62cm for the LG UltraFine 40U990A-W to reach retina quality.
Related Comparisons
Alienware AW2725DF 27" 2024 · 110 PPI · 26.7" · 360 Hz
vs ASUS ROG Strix XG27JCG 2026 · 218 PPI · 27" · 180 Hz
Alienware AW2725DF 27" 2024 · 110 PPI · 26.7" · 360 Hz
vs LG UltraFine 40U990A-W 2025 · 140 PPI · 39.7" · 120 Hz
Alienware AW3225QF 32" 2024 · 139 PPI · 31.6" · 240 Hz
vs ASUS ROG Strix XG27JCG 2026 · 218 PPI · 27" · 180 Hz
Alienware AW3225QF 32" 2024 · 139 PPI · 31.6" · 240 Hz
vs LG UltraFine 40U990A-W 2025 · 140 PPI · 39.7" · 120 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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