The QNAP TL-D400S is a 4-bay SATA DAS enclosure from a well-known vendor. The primary market for this DAS enclosure is to expand the storage of QNAP NAS units. At the same time, since it operates with standard interfaces, it can easily be used as a DAS for PCs and other systems as well.
QNAP TL-D400S JBOD DAS Hardware Overview
The front of the unit has a power LED, status LEDs for the four drives, and then four 3.5″ hot swap drive bays.
We tried the bays and our Windows system recognized inserted drives while the system was on.
The drive trays are tool-less for 3.5″ hard drives, which is a nice touch. If you use 2.5″ SATA SSDs, for example, you will end up using screws.
The rear has a big fan, and then the I/O
Here we get a nose switch for alarms, a SFF-8088 port, a fan speed port, a power switch, and a power input.
The unit came with a SFF-8088 cable. We commonly see SFF-8088 being used for older SAS generations, but in this case, it is SATA-only. One nice feature is that SFF-8088 was designed for high-end external connections, so it is a robust locking connector.
For either QNAP NAS systems or general-purpose PCs, the DAS comes with the QNAP QXP-400eS-A1164.
Onboard, this as an Asmedia ASM1164. That ASM1164 is a PCIe Gen3 x2 SATA controller. Something to note is that this controller does not support a full 24Gbps to the host (it is 16Gbps total) so if your HDDs or SSDs can saturate their interface, then you will be limited by the controller if this is what you use. On the other hand, most 4x HDD setups are not fast enough to be limited by this.
The port is a SFF-8088 port, which is often used for SAS, but this is a SATA-only card. There is not much going on on the back.
With that, let us get to performance.