Fractal Design Define 7 Compact vs Lian Li O11 DYNAMIC MINIcomputed

Datasheet figures next to each other, and the airflow balance, pressure verdict and case air heating that the fans in each box compute to behind that case's own front. Calculated with the CaseFlow model, not measured.

Side by side

Fractal Design Define 7 CompactLian Li O11 DYNAMIC MINI
FormCompact ATX mid towerMini-ITX / Micro-ATX / ATX / E-ATX
Volume42.5 L43.1 L
Dimensions427 × 210 × 474 mm420 × 270 × 380 mm
Frontsolid solid or glass frontsolid solid or glass front
Fan mountsfront 3 × 120/140, top 2 × 120/140, rear 1 × 120, bottom 1 × 120top 3 × 120/140, rear 1 × 120, bottom 3 × 120/140, side 2 × 120/140
Radiator supportfront 360 mm, top 240 mm, rear 120 mm, bottom 120 mmtop 360 mm, bottom 360 mm, side 280 mm
Dust filtersfront, top, bottomtop, bottom, side
GPU length341 mm395 mm
Cooler height169 mm170 mm
Stock fans1 × Dynamic X2 GP-12 (rear), 1 × Dynamic X2 GP-14 (front)none
Stock airflow, max rpm34 in / 0 out CFM–
Stock pressure verdictpositive, worst case includedships without fans
Case air at 290 W+15.5 K–
Stock fan noise19.1 dB(A)–
All mounts, reference fans174 in / 185 out CFM 4 / 3 mounts279 in / 251 out CFM 5 / 4 mounts

With a reference pressure-optimized fan on every mount the O11 DYNAMIC MINI moves more air. The O11 DYNAMIC MINI ships without fans, so only the mount capacity row compares. The pressure verdict describes the stock fan set, not the case: stronger or extra intake fans in the free mounts, or slower exhaust fans, turn a negative balance positive.

Define 7 Compact — mounts and stock fans

TOPBOTTOMREARFRONT · solid

O11 DYNAMIC MINI — mounts and stock fans

side mountsTOPBOTTOMREARFRONT · solid

Case air heating with the stock fans — computed

0 10 20 30 0 100 200 300 400 450 W GPU (open cooler) + 40 W board Define 7 Compact K case air above room

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How these numbers are computed

Each stock fan contributes CFMmax · derate · rpm/rpmmax behind its wall's mounting class: filtered mesh front and side mounts as dust filter, bottom as floor + filter, top and rear as open grille, solid and glass fronts as side-slit intake at roughly half of a mesh front. Front, bottom and side blow in; top and rear blow out.

MountingAirflow bladesPressure-optimized
Open grille0.88 (0.80–0.95)0.88 (0.80–0.95)
Dust filter0.70 (0.60–0.80)0.78 (0.70–0.86)
Floor + filter0.64 (0.52–0.74)0.72 (0.62–0.80)
Solid or glass front0.50 (0.40–0.62)0.58 (0.48–0.68)

Worst case sums intake at the low end of each band and exhaust at the high end; positive there means positive regardless of how the estimates fall. Case air: ΔT = 3.1 · W / throughput (m³/h), with an open-cooler GPU putting its full board power into the case air plus board, RAM and drives. Capacity puts a reference pressure-optimized fan on every mount at max rpm — 120 mm 60 CFM, 140 mm 75 CFM — a generic good fan, not a product.

Mount counts, radiator support and clearances are datasheet figures. Nothing here is measured; the same model runs in CaseFlow.