Not so long ago, it was possible to wonder how long it would take SSDs to overtake hard drives or HDDs in capacity. This has been the case for some time, but the capacity of electronic storage devices based on NAND Flash memory continues to grow at a much faster rate than the capacity of magnetic plates. While WD and Seagate have only just broken the 30TB capacity mark, SSDs now offer four times that. However, the price per unit of capacity will be somewhere else.
122.88TB D5-P5336 series model
Last summer, we wrote about an SSD with a capacity of 61.44 TB, which was released by the Solidigm brand. If you don’t recognize it, it is the former SSD division of Intel, which was bought out by Hynix years ago, which continues to operate Solidigm as its brand. The same Solidigm now comes with another apparently record-breaking SSD with a capacity of 122.88 TB, i.e. double – and plus or minus four times compared to the largest HDDs, which are now 30-32 TB in capacity.
This SSD belongs to the same D5-P5336 series as last year’s 61.44TB drive, so to some extent it is a new capacity rather than a new model. As you can probably guess from the not entirely attractive name, they are storage for servers and data center disk arrays.
Solidigm uses its own NVMe 2.0 controller in them, which has a PCIe 4.0 ×4 interface (so PCIe 5.0 cannot be used yet, which is a shame for performance). The memory is again QLC NAND, it should be 192-layer Solidigm chips, which are probably the evolutionary descendants of the QLC NAND produced by Intel before it got out of the business.
According to the manufacturer, Solidigm D5-P5336 has a sequential read performance of 7400 MB/s, while the sequential write performance is lower – 3200 MB/s. Here it could probably be the sustainable write speed in QLC mode instead of the speed for the “pseudoSLC” write cache that we are used to from consumer SSDs (if the SSD had such a buffer, the speed would be higher). The random access speed is 930,000 IOPS in reading, but only 25,000 IOPS in writing. However, it is not for writing the usual 4KB blocks, but for larger 32KB blocks and with a queue depth of 256 items, i.e. with a relatively deep buffer, they enable better write optimization (for SSDs, numbers are usually given for a queue depth of 32).
These storages are logically intended for applications where data is mainly read and less written or rewritten, which already results from the use of QLC NAND, which has a lower rewriting lifetime by its very nature. However, according to Solidigm, the SSD has an officially guaranteed write life of 0.6 total writes per day for five years, or a total of 134.3 PB of total writes. This works out to some 1100 write cycles per cell, which is really a lot on a QLC, consumer QLC SSDs are usually only guaranteed 300.
In addition to the usual disadvantages of QLC NAND, the high capacity of this SSD is redeemed by one more thing – consumption reaches up to 25 W under load (but less than 5 W at rest). Data center SSDs often have controllers with higher consumption than regular M.2 modules for PCs. But in this case, the high consumption may also be due to the large number of NAND chips that are used (and the controller will probably have more channels than normal ones, server controllers often have 16 channels). This consumption already needs to remember the cooling, which in the servers is ensured by a forced draft through the rack chassis.
Solidigm D5-P5336
The Solidigm D5-P5336 SSD family is produced in three versions: as E1.L and E3.S modules, which are purely server stuff, but also in the U.2 design, which is a 2.5″ design based on the format of previously used notebook hard drives disks (and still existing 2.5″ SSDs with SATA interface).
You could theoretically install this version in a PC as well, its U.2 interface used to be present on some older high-end boards (or Worsktation models) or it can be output with an adapter from a PCIe 4.0 ×4 slot or from an M.2 slot with PCIe connectivity 4.0 x 4. Of course, you need to provide cooling, which most of today’s cabinets do not count on, for example, in popular positions behind the motherboard plate between the cables, about 25W SSD would quickly cook.
But storage will be very expensive, as we don’t expect the price per terabyte of capacity to be better or even the same as HDDs or consumer SSDs. For example, an ordinary QLC SSD (Samsung 870 QVO) costs over six thousand for a capacity of 4 TB (the cheapest QLC modules such as the Kingston NV2 can be found for under six thousand). Multiply that by thirty-one and you have a kind of lower limit of how much a 122.88TB SSD can come to. In reality, the price will probably be much higher than this level, because you are paying extra for a special product and all server SSDs are usually more expensive than those for (in the words of the classics) “dirty people…”. Precisely because of the advantage in price per unit of capacity, there will probably still be room for the existence of magnetic/mechanical HDDs.
Resources: Solidigm, Tom’s Hardware
Source: www.cnews.cz
