be quiet! Pure Base 501 Airflow review

The Pure Base 501 Airflow is an ATX mid-tower-sized case from be quiet!, released in February 2025. It measures 450 x 231 x 449 mm, holds 39.2 L and weighs 6.8 kg. It takes ATX, Micro-ATX and Mini-ITX boards. The Airflow version swaps the standard front for a mesh panel and adds a high-airflow top cover.

That makes it a general-purpose build case. It suits a quiet desktop, a developer workstation or a homelab machine that needs a handful of drives. Reviewers praise its low price, which matters for a case that also gets praise for build quality.

Two Pure Wings 3 140 mm PWM fans come installed, one at the front and one at the rear. be quiet! rates them at 1200 rpm and 57.4 CFM at 100% PWM. You can fit up to six fans in total: two 140 mm or 120 mm on top, two 140 mm or three 120 mm at the front, and one 140 mm or 120 mm at the rear.

Radiator support is broad. The front takes 120, 140, 240, 280 or 360 mm. The top takes 120 or 240 mm. The rear takes 120 or 140 mm. A 360 mm front radiator gives a liquid-cooled build a large area to work with. The top and front filters are removable, and so is the bottom one.

Basic Tutorials ran Prime95 and FurMark together for 30 minutes in a 20 °C room. With the front and rear fans at 100% PWM, the CPU reached 55.0 °C and the GPU 62.5 °C. At 50% PWM, the CPU reached 59.8 °C and the GPU 65.9 °C. Those figures show a modest rise when the fans slow down. One reviewer still called the CPU cooling performance unimpressive, so the reviews disagree on it. If you run a hot CPU, the extra fan positions and radiator options give you room to add cooling.

Reviewers praise quiet operation. be quiet! rates the two included fans at 21.9 dB(A) at 100% PWM. That is a manufacturer figure, not an independent one. Because the fans are PWM, a motherboard fan curve can slow them further. The 50% PWM result above shows the temperature cost of doing that is small in that test.

Reviewers describe the chassis as rigid and well built. be quiet! lists clever cable routing as a feature of the case. Front I/O has two USB-A ports and one USB-C port. The front panel offers just one USB-C connector, which is worth checking against your devices.

The case also supports vertical GPU mounting across up to five PCIe slots, using an optional riser cable. The riser is sold separately.

The CPU cooler limit is 178 mm. Check that number against your cooler before buying. The power supply must be ATX form factor with a maximum dimension of 180 mm. The length limit is not specified. be quiet! doesn't publish a maximum GPU length, so check the case page or ask the manufacturer before fitting a long card.

Storage is modest but workable. The case holds two 3.5-inch drives and five 2.5-inch drives. There are no 5.25-inch bays, so an optical drive or a bay-mounted device will not fit. With two 3.5-inch spots, it suits a small mix of SSDs and a couple of hard drives rather than a large drive array.

be quiet! gives a 3-year warranty.

The Pure Base 501 Airflow suits buyers who value low noise, a sturdy chassis and wide radiator support. Its two included fans and removable dust filters cover the basics. The 178 mm cooler limit, the unpublished GPU length and the lack of 5.25-inch bays are the points to check before you buy. The mixed reviews on CPU cooling mean a hot-running processor may need extra fans or a radiator.