FSP introduced the U661 chassis on November 3, 2024, to address the growing demand for dual-GPU AI workstations. This release matters because it provides a dedicated enclosure for high-density computing setups that standard cases cannot accommodate. Buyers looking to build multi-GPU systems now have a purpose-built option that prioritizes expansion and thermal management.
FSP U661 chassis specifications
The U661 is a large tower case designed specifically for professional and enthusiast workloads. It supports SSI-EEB, E-ATX, and smaller motherboard form factors to ensure broad compatibility. The chassis includes dual GPU support brackets to stabilize heavy graphics cards in multi-GPU configurations.
Specifications
- Motherboard Compatibility: SSI-EEB, E-ATX and smaller
- Expansion Slots: 9 slots
- Front Cooling: 3x 160mm fans
- Rear Cooling: 1x 120mm fan
- Dimensions: 450x258x468 mm
The case measures 450x258x468 mm and is constructed from 0.8mm SPCC steel with integrated soundproofing material. It features nine expansion slots, allowing for extensive hardware configurations. The internal layout supports GPUs up to 420mm in length and ATX power supplies up to 230mm. CPU coolers must fit within a 177mm height limit.
Cooling is handled by pre-installed fans, including three 160mm units in the front and one 120mm unit at the rear. The top panel offers three positions for 120mm or 140mm fans and supports a 360mm AIO liquid cooler. Storage options include multiple bays for both 3.5-inch and 2.5-inch drives. Front I/O ports consist of two USB-A 5Gbps connectors and one USB-C port.
The U661 is currently listed as a new product launch with no pricing or availability details confirmed. The specifications confirm its role as a specialized chassis for dual-GPU AI workstations. The nine expansion slots and robust cooling options define its primary use case.
Does the 9 expansion slot count include the slots occupied by the dual GPU support brackets or are those separate
The spec sheet lists 9 slots total. The brackets are mounting hardware attached to the case rails so they do not consume a PCIe slot themselves.
nine slots for ai cards sounds like a nightmare to route cables tbh
I want to see thermal throttling data under sustained tensor core loads before I trust the cooling claims
No price listed yet. Cases like this usually cost more than the GPUs inside them due to the steel thickness
The 177mm CPU cooler limit is tight for dual GPU setups. Air cooling might restrict airflow between the cards significantly
Is this compatible with standard ATX power supplies or do they need the SFX form factor to save space
It supports ATX power supplies up to 230mm in length. You just need to ensure your PSU does not exceed that dimension
finally a case that looks like it belongs in a server room 👀
Soundproofing material in a dual GPU tower is a good idea. These things sound like jet engines when under load