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.
| BitFenix Colossus | Fractal Design Define 7 XL Black Solid | |
|---|---|---|
| Form | ATX Full Tower | Full tower |
| Volume | 79.6 L | 82.0 L |
| Dimensions | 582 × 245 × 558 mm | 604 × 240 × 566 mm |
| Front | solid solid or glass front | solid solid or glass front |
| Fan mounts | front 3 × 230/140/120 | front 3 × 140/120, top 3 × 140/120, rear 1 × 120, bottom 2 × 120 |
| Radiator support | front 230 mm | front 480 mm, top 480 mm, rear 120 mm, bottom 280 mm |
| Dust filters | – | front, top, bottom, psu |
| GPU length | – | 530 mm |
| Cooler height | – | 185 mm |
| Stock fans | none | 2 × Dynamic X2 GP-14 (front), 1 × Dynamic X2 GP-14 (rear) |
| Stock airflow, max rpm | – | 68 in / 60 out CFM |
| Stock pressure verdict | ships without fans | marginal: mid +8.2 CFM, worst -10.3 CFM |
| Case air at 290 W | – | +7.8 K |
| Stock fan noise | – | 23.9 dB(A) |
| All mounts, reference fans | 130 in / 0 out CFM 3 / 0 mounts | 217 in / 251 out CFM 5 / 4 mounts |
With a reference pressure-optimized fan on every mount the Define 7 XL Black Solid moves more air. The Colossus 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.
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.
| Mounting | Airflow blades | Pressure-optimized |
|---|---|---|
| Open grille | 0.88 (0.80–0.95) | 0.88 (0.80–0.95) |
| Dust filter | 0.70 (0.60–0.80) | 0.78 (0.70–0.86) |
| Floor + filter | 0.64 (0.52–0.74) | 0.72 (0.62–0.80) |
| Solid or glass front | 0.50 (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.