PNY RTX 4070 Ti Super VERTO in Lian Li A3-mATX Bottom Fan Clearance Analysis
The Lian Li A3-mATX is a flexible 26.3-liter Micro-ATX case designed to house full-sized hardware within a compact footprint. Installing the PNY GeForce RTX 4070 Ti Super 16GB XLR8 Gaming VERTO EPIC-X into this chassis requires calculating exact bottom floor clearances to prevent fan shroud interference.
Dimensional Matrix & Clearance Breakdown
The table below summarizes physical clearance metrics for the PNY RTX 4070 Ti Super VERTO inside the Lian Li A3-mATX:
| Dimension Parameter | Hardware Specification | Chassis Allowance Limit | Net Margin / Clearance State |
|---|---|---|---|
| GPU Total Length | 305.1 mm | 415.0 mm Max Length | +109.9 mm Safe Margin |
| GPU Total Thickness | 60.4 mm (3.0-Slot) | 82.4 mm Slot-1 Floor Depth | +22.0 mm Floor Clearance |
| Bottom Fan Setup (25mm Standard) | 25.0 mm Thickness | 22.0 mm Floor Clearance | -3.0 mm Overlap (Collision) |
| Bottom Fan Setup (15mm Slim) | 15.0 mm Thickness | 22.0 mm Floor Clearance | +7.0 mm Safe Clearance |
PCIe Slot Placement & Bottom Floor Clearance
On standard B650M Micro-ATX motherboards, the primary PCIe 4.0/5.0 x16 slot is located in Slot 1 position. The total distance from the primary PCIe slot center line to the bottom floor pan of the Lian Li A3-mATX is approximately 82.4 mm.
The PNY RTX 4070 Ti Super VERTO measures 60.4 mm in thickness, occupying 3.0 full expansion slots. Subtracting card thickness (60.4 mm) from total floor depth (82.4 mm) leaves a remaining clearance gap of 22 mm between the lower edge of the GPU shroud and the floor pan.
Bottom Fan Interference & Slim Fan Solutions
Because the remaining clearance gap above the chassis floor is only 22 mm, installing standard 25 mm thick 120 mm bottom intake fans causes a 3 mm physical collision with the PNY GPU shroud. Forcing 25 mm fans onto the floor pan will press against the GPU fan blades, causing mechanical scraping or locking the fans entirely.
To supply fresh air to the GPU safely, builders must install 15 mm thick slim intake fans (such as Noctua NF-A12x15 or SilverStone FW121) on the floor pan. Slim 15 mm fans fit inside the 22 mm window with a 7 mm clearance gap, delivering direct airflow without shroud contact.
Power Supply Bracket Positioning & Air Cooling Synergy
The Lian Li A3-mATX features a versatile front PSU mounting bracket. When evaluating ATX vs SFX power supply brackets in mATX cases, installing a compact SFX PSU or mounting a short 140mm ATX power supply in high bracket positions (F1/F2) preserves full 415 mm GPU length allowance. This easily accommodates the 305.1 mm PNY card while keeping PSU cables clear of the GPU backplate.
For CPU cooling, the A3-mATX provides 165 mm of air cooler height clearance. This easily accommodates high-performance dual-tower coolers like DeepCool AK620 dual tower air coolers, creating an effective push-through thermal loop across the motherboard chamber.
Builder Summary
- Horizontal GPU Fit: PASSED — 109.9 mm length margin to front panel.
- Standard 25mm Bottom Fans: FAILED — 3 mm collision with GPU shroud.
- Slim 15mm Bottom Fans: PASSED — 7 mm clearance gap when using 15 mm slim fans on the floor pan.
- Cross-System Compatibility: For adjacent component clearances, review our analysis on Fsp ATX 3.0 power supply requirements.