Lian Li A3: can you keep your ATX PSU with a long GPU and 360 AIO?
· By Weerasak
Document-based guide · Methodology and limits
Quick answer
The A3’s maximum GPU length is not available in every PSU and cooling layout. Identify the exact mounting position before replacing a working PSU. The checker below covers one documented top-360-AIO arrangement, not every possible A3 build.
The missing specification is the layout
You want a smaller case, not necessarily a new power supply. Start by recording the parts you intend to keep: exact PSU model and body length, full graphics-card model, AIO model, fan thickness and storage devices. “850W ATX” does not tell you how much room the supply occupies, and a GPU family name does not identify the board-partner cooler.
Lian Li publishes separate A3 compatibility configurations. For the calculation here, open ATX PSU FRONT or ATX PSU FRONT with offset bracket. Find front position F2.5. Do not use the side-mounted PSU chart or move a limit from another bracket position into this check.
The selected diagram row supplies the length limit.
Listed length minus your exact card length gives a nominal margin.
Cable routing, tube bends, card height and assembly access are not solved by that subtraction.
Local check · no AI or sign-in
A3 front F2.5 length check
Limited to ATX PSU rows, front position F2.5, top 360 mm AIO and a horizontal GPU. It does not validate every A3 layout.
Inputs are processed in this browser and are not saved or sent by this checker. No product page opens automatically.
The narrow slice of the official matrix used here
| Exact ATX PSU body length | Standard bracket: GPU length limit | Offset bracket: GPU length limit |
|---|---|---|
| 140 mm | 334 mm | 415 mm |
| 150 / 160 / 180 / 200 / 220 mm — separate published rows | 334 mm | 334 mm |
The two linked front-mount diagrams are the source of these values. They describe a nominal supported envelope, not a promise about a particular cable plug or radiator end tank. This intentionally small table does not reproduce the many other front and side positions.
A PSU labelled 155 mm is not a 150 mm record. The checker returns “cannot confirm” for unlisted lengths rather than interpolating. Likewise, an SFX or SFX-L supply needs its own diagram even if its length happens to equal an ATX row. Selecting a smaller supply here to obtain a larger green-looking number would answer the wrong question.
Three shopping decisions, not three automatic approvals
140 mm ATX PSU, 350 mm GPU, top 360 AIO
At front F2.5 without the offset bracket, the length arithmetic is 334 − 350 = −16 mm. With the documented offset arrangement it is 415 − 350 = 65 mm. That makes the offset layout worth checking before buying an SFX PSU. It does not say that 65 mm is spare connector-bend room: the calculation is along the card’s length axis.
160 mm ATX PSU, 350 mm GPU, top 360 AIO
Both F2.5 rows shown above yield −16 mm. In this specific arrangement, adding the offset bracket does not cure the length conflict. Compare another manufacturer-documented position or cooling arrangement, then price a PSU change only if the existing parts cannot be retained. Do not substitute the 140 mm row simply because the power supply has detachable cables.
Length fits, but bottom fans occupy the GPU space
Lian Li separately limits GPU thickness to 61 mm with 25 mm bottom fans. An illustrative 65 mm-thick card exceeds that dimension by 4 mm, regardless of a positive length margin. The checker treats that as a conflict. It does not convert the rule into a universal “GPU thickness plus fan thickness” budget for arbitrary slim fans or radiators.
A keep-first assembly checklist
- Match the drawing. Confirm the case edition, front/side mounting, position label and actual offset hardware. A bracket in the accessories box is not the same as an installed bracket.
- Draw the complete cooling envelope. Use the AIO’s external dimensions, radiator plus fans, tube connections and cable exits. The “360” name identifies a radiator class; it is not the thickness measurement.
- Reserve the installed cable routes. Identify where each PSU plug exits and where the GPU power connector faces. Ask the component maker about required bends; do not invent one cable allowance for every connector.
- Check assembly access. Decide how the card enters, how its bracket is secured, and whether its latch remains reachable. Do not use a forced fit as evidence that a published limit is wrong.
- Check the rest of the case. Keep the SSD tray, drive cage, motherboard headers and fan positions on the same plan. Moving the PSU can change which space is available elsewhere.
Before any trial assembly, shut down and disconnect AC, then follow the case and component manuals. Do not open the PSU or manipulate internal parts while powered. A photograph with one panel removed is not evidence that all panels close without pressure.
If the desired layout does not work
| Priority | Candidate change | What must be rechecked |
|---|---|---|
| Keep the current PSU | A different documented mounting/cooling arrangement | AIO location, tubes, fans, storage and cable access |
| Keep the GPU and AIO | A supply fitting a supported layout | Capacity, approved cables, its own mounting chart and total conversion cost |
| Keep every component | A less restrictive case | All dimensions, headers and cooling layout in that case |
These are alternatives to investigate, not a recommended shopping list. If you do replace a PSU, do not carry its predecessor’s modular cables across without an exact manufacturer approval. Our cable-reuse guide handles that separate decision.
Questions to resolve before ordering
Does a positive margin mean the GPU fits?
No. It only clears the dimension being compared. The SFF checker can help organise other available measurements, but neither tool knows a cable bend or unpublished dimension you have not supplied.
Can a 335 mm card use a 334 mm limit?
The calculation is one millimetre outside the published envelope. We do not certify a squeeze fit from another builder’s photograph. Seek a documented alternative or exact manufacturer confirmation before committing to that combination.
Sources and review scope
Manufacturer documents checked October 27, 2026. This guide does not represent hands-on testing of these hardware combinations. Recheck the exact model's manual when configuring your build.