The Xbox Series X|S SSD Expansion Card teardown reveals 4D NAND and Phison E19T chipset

Xbox Series X SSD Header

Another Xbox Series X preview embargo has lifted yesterday, allowing journalists and influencers with access to go that bit further with their coverage of Microsoft’s next-gen console. So far, in fact, that Venture Beat were allowed to rip apart the Seagate 1TB SSD Expansion Card and reveal its innards to the world.

What it reveals is interesting and shows a path forward for larger expansion cards and more third parties to produce them, and goes some of the way to justifying the SSD’s £220 / $220 price tag, while not having the same raw speed of the SSDs required for the PlayStation 5.


Visit Venture Beat to see the images of a ripped open SSD.

The 1TB SSD Expansion Card combines a Phison E19T SSD controller with a single 1TB chip of SK Hynix’s ‘4D NAND’. Essentially, these are relatively upper-end mainstream parts combined into a very compact form factor with a semi-custom connector, all of which adds up so something that’s accessible for use by the most average of Joes.

The drive’s housing is metal for the length that can be inserted into the console, which acts as a heatsink and can be cooled somewhat by the internal cooling system, leading up to the plastic end that should be easily touched no matter how hard the drive is working.

The Phison E19T is a PCIe Gen 4.0 SSD controller that’s intended for mainstream products. It’s capable of up to 3.75GB/s of throughput, and works as a DRAM-less controller – DRAM helps to level out loads for maintaining write speeds, in particular. In other words, it’s capable of a lot more than the 2.4GB/s that the Xbox Series X|S SSD is specced at. It’s also able to support up to 2TB of NAND memory, though this would require two NAND chips at 1TB each.

And so we come to the 1TB ‘4D NAND’. No, it’s not working in four dimensions, but it’s instead a catchy buzzphrase to describe how it’s packaged, layering more components on top of one another to achieve higher data density and higher speeds. SK Hynix do not currently produce QLC memory, so this will be faster, more durable TLC instead, which helps compensate for being DRAM-less.

These chips are combined on a small PCB that seems to be around the size of an M.2 2242 board – that’s 22mm wide and 42mm long – which is half the length of the more common M.2 2280 SSDs. As far as I’m able to see online, there’s no readily available 1TB SSD in this form factor which only has chips on one side of the PCB, and certainly not at this speed.

The board then ends in a semi-custom CFexpress card connector, which Microsoft have seemingly modified to support PCIe 4.0, instead of the standard’s PCIe 3.0.

All of that means that there’s plenty of room for growth and competitive products to be offered. For one, the Phison E19T can handle larger pools of storage, and we could see drives with NAND chips on both sides of the PCB to double the storage, and Microsoft could open the platform to include newer or more feature-filled SSD controllers that can handle higher capacities. There’s also no reason why we couldn’t see physically larger drives that match M.2 2260 sizes, or (if they wanted to be really open (which they won’t)) adapters to allow regular SSDs to be plugged in.

For now, of course, Seagate’s SSD expansion is the only on the market, so if you’ll have to stomach the associated costs if you simply must have a larger internal SSD capacity on Xbox Series X|S.

Source: Venture Beat

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