Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | BenQ - X3100i | Optoma - UHD35STx |
|---|---|---|
| Brightness | 3300 lm | 3600 lm |
| Light source | LED | Lamp |
| Short-throw | false | true |
Between the X3100i and UHD35STx, the X3100i comes out ahead in light source, while the UHD35STx wins on brightness / short-throw. Overall, the X3100i scores 76.6 and the UHD35STx scores 78.9 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (76.6 vs 78.9). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the X3100i if you care most about light source. The biggest gaps in its favor are light source. The single most decisive one: Light source: LED (vs Lamp).
Pick the UHD35STx if you care most about brightness / short-throw. Its strongest claims are brightness, short-throw. The single most decisive one: Brightness — 9.09% more. 3600 lm vs 3300 lm.
Both ship with comparable resolution, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: BenQ - X3100i or Optoma - UHD35STx?
Optoma - UHD35STx leads the current Mars Score by 2.3 points.The more useful decision is the trade-off behind that result: compare brightness, light source, short-throw against the way you will actually use the product.
Choose BenQ - X3100i if…
BenQ - X3100i has the measurable edge on light source.
Choose Optoma - UHD35STx if…
Optoma - UHD35STx has the measurable edge on brightness lumens, is short throw.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why BenQ - X3100i wins
- ▲Light source: LED (vs Lamp).
Why Optoma - UHD35STx wins
- ▲Brightness — 9.09% more. 3600 lm vs 3300 lm.
- ▲Short-throw: true (vs false).
Spec comparison
Image
| Spec | BenQ - X3100i | Optoma - UHD35STx |
|---|---|---|
| Resolutionⓘ | 4K | 4K |
| Brightnessⓘ | 3300 lm | 3600 lmlead |
| Contrast | 600000:1 | 1000000:1 |
| Light source | LEDlead | Lamp |
| Short-throw | false | truelead |
Smart & Connectivity
| Spec | BenQ - X3100i | Optoma - UHD35STx |
|---|---|---|
| Smart OS | Android TV | None |
| HDMI inputs | 2 | 2 |
| Built-in speakers | true | true |