Kioxia Announces XG8 Client SSDs: PCIe 4.0 and BiCS5 For OEMs

Kioxia this morning is rolling out its next-generation of full-size client SSDs, the XG8 family. Like its predecessors, the XG8 is aimed at the OEM market, for customers who are after a full M.2 2280-sized drive and are looking for better performance than the company’s more integrated and compact BG-series drives. Notable features for the latest-generation drive include a PCIe 4.0-capable controller, as well as capacities as high as 4TB.

And while we’d normally use the company’s previous-generation drive as a baseline to illustrate what’s new with the latest drive, today’s announcement of the XG8 is a bit weird, even by Kioxia’s own OEM-centric standards. The predecessor to the XG8 is the XG7, which was launched in November of 2020 with a very similar feature set: a PCIe 4.0 M.2 2280 SSD with capacities up to 4TB. However, for reasons we’re still not entirely clear on, the XG7 only saw a very limited deployment among OEMs, to the point that Kioxia never even put together a proper product page for the part. As a result, the company is taking a mulligan of sorts and is starting fresh with the XG8, positioning it as the successor to the PCIe 3/BiCS4-based XG6.

Starting with the basics, the XG8 is a M.2 2280 form factor SSD with a PCIe 4.0 x4 connection. Kioxia is using their 5^th generation, 112-layer BiCS5 NAND, with capacities ranging from 512GB up to 4TB. That NAND is being paired with their own in-house controller, which offers NVMe 1.4 support as well as the option for the usual OEM-centric security features such as TCG Pyrite 2.01 and TCG Opal 2.01.

Kioxia classifies the drive as a high-end product – particularly in relation to the BG5 – though as this is again by OEM standards, it’s a bit up in the air by enthusiast standards. Unfortunately, Kioxia isn’t providing any hard performance figures in advance of today’s announcement, so we don’t even have on-paper numbers to go by. For the moment, Kioxia is primarily throwing around 2x the performance of the XG6, most of which I’d expect to come from the switch to PCIe 4.0 and the additional host-to-controller bandwidth that affords.

Based on the lack of specification information and the fact that so many figures line up with the absentee XG7, it’s not at all clear what sets the XG8 apart from its more recent sibling. Presumably something has changed, if only to avoid another misfire, but at this point we’d just be guessing. Though it is notable that this drive family appears to be doing away with the ‘P’ designation that Kioxia used for high capacity drives in previous generations (e.g. XG6-P), as there is no mention of that sub-family of drives this time around.

Finally, this is probably one of the last BiCS5 client drives we’ll see from Kioxia. The WD/Kioxia joint venture has been producing BiCS5 NAND since late 2020, and according to recent WD earnings calls, 162L BiCS6 is expected to go into mass production late this year.

In the meantime, the XG8 is now sampling to Kioxia’s customers, and should start showing up in OEM laptops and desktops soon.