The Phanteks XT Pro Ultra wins in 6 out of 8 comparable specs. Its biggest advantage is Max Radiator (50% better).
O11 Air Mini wins in 2 specs (3.5" Bays: 100% better).
Recommendation
Choose XT Pro Ultra if you want the best overall performance — especially max radiator.
Choose O11 Air Mini if 3.5" bays matters more to you.
| Spec | Lian LiO11 Air Mini | PhanteksXT Pro Ultra |
|---|---|---|
| Design | ||
| Type | ATX Mid Tower | ATX Mid Tower |
| Side Panel | Tempered Glass | Tempered Glass |
| Weight | 7.5 | 10.5 |
| Compatibility | ||
| Max GPU Length | 362 mm | 435 mm+20% |
| Max Cooler Height | 155 mm | 181 mm+17% |
| Max PSU Length | 180 mm | 220 mm+22% |
| Max Radiator | 280 mm | 420 mm+50% |
| Motherboard Support | ATX, EATX, Micro ATX, Mini ITX | ATX, EATX, Micro ATX, Mini ITX |
| Cooling | ||
| Included Fans | 3 | 4+33% |
| Storage | ||
| 2.5" Bays | 2 | 3+50% |
| 3.5" Bays | 4+100% | 2 |
| I/O | ||
| Front I/O | 1x USB-C, 2x USB-A 3.0, Audio | 1x USB-C, 2x USB-A 3.0, Audio |
| Price | ||
| MSRP | $110−35% | $170 |
| Release Date | Sep 2021 | Jul 2024 |
