The A4-H2O is what you build when you've decided 11 liters is the goal and you're willing to accept the trade-offs to get there. The sandwich layout mounts the GPU behind the motherboard, the removable front and top open up surprisingly easily for a case this small, and the 240 mm AIO support is the differentiating feature against most cases in this volume class. Cable management is the dealbreaker for some builders — there's almost nothing in the way of dedicated routing. GamersNexus calls cable management the case's main flaw; everything else is praised.
Full review
Maximum Density
The A4-H2O is a Lian Li and DAN Cases collaboration built on the lineage of the original A4-SFX, and its entire reason for existing is to hit 11 liters. Measuring roughly 326 x 140 x 244 mm, it's among the smallest cases that still fit a full triple-slot graphics card. The sandwich layout mounts the GPU vertically behind the motherboard via an included riser, with the two halves stacked to keep the external footprint as small as physically possible.
The build mixes an aluminum exterior with an SPCC steel interior, which gives it a more premium feel than the price suggests, and mesh covers all four user-facing panels to keep air moving through the tight interior. Removable front and top sections make the case more approachable to build in than its size implies, though it remains a step up in difficulty from the NR200 or Terra.
Liquid Cooling Focus
What differentiates the A4-H2O from most cases in its volume class is genuine AIO support. A removable top bracket lets you install a radiator up to 240 mm, with clearance for a fan-and-radiator combo around 55 mm thick, so you can run liquid cooling on a CPU in a chassis this small. Air-cooled builds are far more constrained, with CPU cooler height limited to roughly 55 mm, which is why this case is really designed around an AIO.
GPU clearance runs to 322 mm for triple-slot cards, and Lian Li offers a PCIe 5.0 riser revision for RTX 50-series builds alongside the standard PCIe 4.0 cable. Power is SFX or SFX-L, though SFX-L clearance is tight enough that reviewers recommend planning cable routing in advance. The case is NVMe-focused by design, with no 3.5-inch drive bays.
Who Should Buy It
The A4-H2O is for the builder who has decided that 11 liters is the target and is prepared to accept the trade-offs that come with it. If you want a liquid-cooled, GPU-forward machine in the smallest reasonable envelope, few cases get you there as cleanly. The premium-feeling aluminum shell at around $156 makes it a relative bargain for the segment.
The recurring complaint, echoed by GamersNexus and most other reviewers, is cable management: there are essentially no dedicated tie-downs or routing channels, so a clean build takes patience. That, plus the air-cooling height limit and higher overall build difficulty, makes this a case for experienced or determined SFF builders rather than first-timers. If you'd rather not fight the wiring, the NR200 is the easier path; the A4-H2O is the one you choose when small is the whole point.
Strengths
- +11 L volume — among the smallest cases that still fit triple-slot GPUs
- +Designed around 240 mm AIO water cooling, with removable top bracket for radiator install
- +Mesh on all four user-facing panels keeps thermals manageable despite the tight volume
- +Aluminum exterior and SPCC steel interior — premium build feel for the price
- +Comes with a PCIe 4.0 riser cable; PCIe 5.0 revision available for RTX 50-series builds
Watch-outs
- −Cable management is the most-cited frustration — no dedicated tie-downs or channels
- −Limited drive support (no 3.5" bays) by design — NVMe-only builds are expected
- −SFX power supply only, and clearance for SFX-L is tight
- −Build difficulty is higher than the Cooler Master NR200 or Fractal Design Terra
How it compares
The A4-H2O is the smallest case in this round-up at 11 L vs the Cooler Master NR200's 18.25 L and Hyte Revolt 3's 18.4 L. Vs the Fractal Design Terra (10.4 L), the A4-H2O trades the Terra's wood-and-aluminum finish for a stronger mesh airflow story and proper 240 mm AIO support. Not the build for first-timers — the Jonsbo C6-ITX and Cooler Master NR200 are both significantly easier to work in.
Who this is for
At a glance: experienced SFF builders who want the smallest possible case that still fits a triple-slot GPU and 240 mm AIO.
Why you’d buy the Lian Li A4-H2O
- 11 L volume — among the smallest cases that still fit triple-slot GPUs.
- Designed around 240 mm AIO water cooling, with removable top bracket for radiator install.
- Mesh on all four user-facing panels keeps thermals manageable despite the tight volume.
Why you’d skip it
- Cable management is the most-cited frustration — no dedicated tie-downs or channels.
- Limited drive support (no 3.5" bays) by design — NVMe-only builds are expected.
- SFX power supply only, and clearance for SFX-L is tight.
Rating sources
Our 4.4 score is the average of these published ratings. More about methodology.
