Introduction

Seagate is one the most well-known names in the storage industry, and their hard drives are used by hundreds of millions of people around the world. Together with Western Digital, Seagate basically owns the market for mechanical hard drives, but that market is under attack from flash-based SSDs. SSDs achieve faster transfer rates and lower access times than hard drives because of their solid-state nature without any moving parts. On the other hand, the price per GB for SSDs is higher than with HDDs, but prices have been steadily coming down over the years, which is now driving more and more budget-minded people into exploring what SSDs can offer over mechanical drives.

Today's SSD review will cover the Seagate BarraCuda 120 in its 1 TB variant. Unlike the majority of recent SSD reviews, which were all M.2 NVMe, this one uses a 2.5" form factor with the SATA interface. I'm actually looking forward to this review as there's still a significant demand for storage that doesn't take up precious M.2 slots—most motherboards only have one or two of those, but plenty of SATA connectivity. Four SATA ports are standard on all recent motherboards, most have six, some even have eight.

Internally, the Seagate BarraCuda uses a STXZA01F5578 controller, which is a rebranded Phison S12 design. The flash chips are Intel 3D TLC, probably 96 layers. As expected, the SSD includes pseudo-SLC caching to improve performance. The BarraCuda also has a DRAM cache chip to avoid the random write performance issues of DRAM-less SSDs.

Seagate is offering the BarraCuda 120 in capacities of 250 GB ($55), 500 GB ($70), 1 TB ($115), and 2 TB ($230). Endurance for these models is set at 150 TBW, 300 TBW, 600 TBW, and 1170 TBW respectively. Seagate also includes a five-year warranty.

The Drive

We received our drive in just an anti-static bag without any retail packaging. It conforms to the dimensions set forth by the 2.5" form factor. It is made out of metal to improve its durability and is only 7 mm thick, which ensures it will fit into modern notebooks.


The Seagate BarraCuda SSD uses the SATA 6 Gbps interface. It is compatible with any older SATA standard, but will, in such a case, work at reduced performance.


On the PCB, you'll find the controller, eight flash chips, and a DRAM chip.

Chip Component Analysis

The Seagate STXZA01F5578 controller is a customized version of the Phison PS3112-S12, which is an 8-channel flash controller with TLC support.


The TLC flash chips are made by Intel, using their 3D TLC technology, probably with 96 layers.


A Hynix DDR3-1866 chip provides 256 MB of fast DRAM storage for the controller to store the mapping tables.

Test Setup