Closer Look at Toshiba THNSNH256GCST
The SSD we’re discussing today comes from Toshiba’s newest THNSNH series and has a capacity of 256 gigabytes. Its model name is THNSNH256GCST. It is a 2.5-inch drive with a thickness of 7 mm and SATA 6 Gbit/s interface. The THNSNH series includes two more modifications of this model with the same storage capacity: one has the standard thickness of 9.5 mm and another is designed in mSATA form-factor.
The THNSNH256GCST SSD seems to be made for PC integrators rather than for retailers. It comes without any packaging and its appearance reminds us of industrial equipment. It doesn't look like a premium PC component for enthusiasts.
The slim ultrabook-friendly case of this SSD consists of two metal halves with punched-out depressions which seem to be meant for various stickers. The SSD has only one sticker, though. It shows you the product’s part and serial numbers and some barcodes. The barely discernible perforation is the only attempt at any embellishment on the brutal body of this SSD.
Our THNSNH256GCST is not shipped in a box, so it comes without any accessories. We know, however, that it is available in retail in Asian markets in a cute-looking package and under better-sounding names such as Toshiba Q series or HG5d.
The SSD makes up for its external deficiencies with its neat craftsmanship and exciting internals. The parts of the case are fitted perfectly together. The memory chips have thermal pads to dissipate heat via the case. And most importantly, the PCB carries a set of chips we've never seen before. So, the Toshiba THNSNH256GCST is not a replica of another device but something completely new. Let’s see what it has inside.
Its heart is Toshiba’s own TC58NC5HA9CST controller whose origin can be easily traced by the word “Marvell”. Toshiba came up with innovative revisions of JMicron and SandForce controllers before, and now the company does the same with Marvell. The TC58NC5HA9CST seems to be related to the Indilinx Everest 2, representing a revised version of some Marvell controller with Toshiba’s firmware. We don’t have any proof, however, except that the firmware has certain unique features and implements a proprietary error correction method (Quadruple Swing-By Code).
There is an empty place next to the controller. It must be reserved for a SDRAM chip but Toshiba’s engineers didn’t install an external buffer for some reason. Considering that Marvell controllers cannot do without buffer memory, the latter must be integrated into the controller chip.
The SSD has eight flash memory chips Toshiba TH58TEG8CDJBASC. Each has a capacity of 32 GB and contains four 19nm MLC NAND dies. The flash memory is connected via the cutting-edge Toggle Mode 2.0 interface with a peak bandwidth of 400 Mbps on each of the eight controller channels. The controller can use 4-way interleaving in the THNSNH256GCST.
We must admit that there is nothing particularly innovative about the Toshiba THNSNH256GCST as it is generally alike to the Plextor M5 Pro, for example. However, Toshiba has customized the Marvell controller for its SSD and backs it up with proprietary firmware which may affect the SSD's performance considerably in different applications. By the way, Toshiba has a rather extensive range of server-oriented SSDs and follows a very conservative policy in terms of firmware updates. The company just never updates firmware for already released SSDs.
Here is a summary of the product specs:
- Controller: Toshiba TC58NC5HA9CST;
- Interface: SATA 6 Gbps;
- Flash-memory: synchronous 19 nm Toggle Mode MLC NAND;
- Size: 256 GB / 238 GiB;
- Cache-memory: no data;
- Sequential read speed: 534 MB/s;
- Sequential write speed: 482 MB/s;
- Random read speed (4 KB blocks):80,000 IOPS.
With Marvell technologies and fast flash memory, the Toshiba THNSNH256GCST seems to be good enough to compete with the flagship offers from other companies. As a matter of fact, Marvell-based SSDs are generally top-performance products.
The formatted capacity of the Toshiba THNSNH256GCST is 238 gigabytes. As is often the case, the manufacturer reserves about 7% of the drive’s full capacity for a reserve memory pool, garbage collection and wear leveling. The proprietary error correction QSBC requires some storage, too.
There is only one aspect from which the Toshiba THNSNH cannot match the best offers of other brands, despite the impressive specs. It is the warranty period, which is set at 1 year only. We don’t see any real reasons for that as the SSD employs high-quality flash memory with a typical service life.