Kioxia BG5 1TB 2230 Review (Steam Deck)

steam deck ssd swapAlthough it is commonly used for WiFi modules, you would rarely have encountered NVMe SSDs in the M.2 2230 form factor until recently. Then about a year ago, there was a sudden uptick in demand for these tiny but fast storage devices.

The reason was of course that Valve started shipping the Steam Deck in 2022. This handheld gaming PC was and still is available in three variants that all use M.2 2230 storage in capacities up to 512 GB.

Of course, even 512 GB is a limiting factor when it comes to modern games, which frequently gobble up 50–100 GB each. The 256 GB model might not hold more than a handful of games, and the one with just 64 GB of eMMC storage basically mandates the use of a microSD card.

The 1TB Kioxia BG5 2230

Needless to say, lots of Steam Deck owners soon came looking for higher-capacity SSDs in the rare form factor, and the market was seemingly caught completely unaware. There were barely any 2230 M.2 SSDs to be found anywhere, prompting some to shoehorn in 2242 models (something that Valve representatives strongly discouraged).

With notable exceptions such as Sabrent, most SSD manufacturers have yet to launch M.2 2230 drives suitable for the Steam Deck, so even in 2023 there are relatively few options.

The Kioxia BG5 that we are testing today was clearly not designed with the Deck in mind. It is primarily an OEM part targeted at various small form factor devices and it is quite a rare find in retail.

That doesn’t make it less usable in the Steam Deck, as the handheld will accept any NVMe drive that fits in its M.2 2230 slot.

Kioxia BG5 2230
1,024 GB512 GB256 GB
Form FactorM.2 2230M.2 2230M.2 2230
PCIe 4.0 x4/
NVMe 1.4
PCIe 4.0 x4/
NVMe 1.4
PCIe 4.0 x4/
NVMe 1.4
Sequential Read3,500 MB/s3,500 MB/s3,400 MB/s
Sequential Write2,900 MB/s2,700 MB/s1,900 MB/s
Random Read500K IOPS400K IOPS350K IOPS
Random Write450K IOPS430K IOPS360K IOPS
Power Draw
4.3 W4.2 W4.1 W
2230 Vs. 2280 size comparison

Size comparison: 2230 Vs. 2280.

As is evident from the specs, the Kioxia BG5 was not built to compete with the fastest M.2 SSDs. It is rather an entry-level Gen4 drive that performs on par with mainstream Gen3 and budget Gen4 SSDs.

Note that it is not just sold in the 2230 form factor but also comes in the standard 2280 length (with otherwise identical specifications). The 1TB or more accurately 1,024 GB version is the largest capacity and also, for the same reason, the fastest in the lineup. It also draws the most power while active, but the difference is quite negligible.

Instead of an onboard DRAM buffer, the BG5 uses an HBM (Host Memory Buffer) – i.e. a small amount of the host device’s RAM – to improve performance. As it’s an OEM part, no endurance information is provided other than a traditional 1,500,000-hour MTBF rating.

Steam Deck Benchmarks

As a fully functional x86 PC, the Deck can of course run Windows. However, most users will likely want to stick with Valve’s purpose-built Linux distribution, making this the most interesting testing environment. Our original Steam Deck SSD, the 256 GB Phison E13 variety, was cloned to the Kioxia BG5 via an external M.2 NVMe enclosure to ensure reasonably comparable results.


The usual Windows benchmarking tools are unavailable in the Deck’s SteamOS 3 (a custom flavor of Arch Linux with the KDE Plasma desktop environment), but we can still use something quite comparable to the widely used CrystalDiskMark. That would be KDiskMark, which can be downloaded and installed straight from the built-in Discover Store. KDiskMark is based on Flexible I/O Tester and offers a GUI with presets that mimic CrystalDiskMark.

Kioxia BG5 sequential performance

Sequential performance as measured by KDiskMark (1M-Q8T1) is about what you might expect from the BG5’s specs, seeing as the parameters are seemingly identical to those used by CrystalDiskMark. It is also not surprising that the much smaller 256 GB original (Gen3) is significantly slower here.

Kioxia BG5 random performance

Moving on to random performance, we opted to focus on the Q1T1 data, as this is generally a good proxy for daily use in the real world (as opposed to copying large files in pre-determined sequences). The differences even out here, with the Phison E13 drive performing quite well in comparison.

Game Loading Times

Loading games is something that the typical Steam Deck will be tasked with often, and keeping those times to a minimum is clearly a key feature for any SSD. The following tests consist of loading a specific save file from the game’s start screen.

kioxia bg5 game loading times

These manually measured times (via video recordings) are hardly accurate down to the millisecond, but you can certainly spot some overall tendencies. The NVMe SSDs are quite evenly matched, but the Kioxia BG5 never fails to win the race, even if it’s only by a hair.

What is perhaps most striking is that the microSD card is not that far behind. On paper, the microSD card only offers a small fraction of an M.2 NVMe drive’s performance (90 MB/s sequential according to KDiskMark), but this does not in any way translate to proportional increases in load times.


Expanding the Steam Deck’s storage capacity is something that most owners will want to do eventually. The main question is how and at what cost. Apparently, the Deck is by no means disastrously slow when launching games from a microSD card, but any decent SSD is faster.

Another argument in favor of prioritizing an SSD upgrade is that the price difference between a 1TB microSD card and a 1TB NVMe SSD is relatively small. In the United States, 1TB microSD cards start at about $100, whereas 2230 M.2 drives are now down to $150 in some cases.

Coming back to the 1TB Kioxia BG5, this drive is definitely a worthy upgrade at the right price – especially compared to some no-name alternatives that have recently appeared in the market. Although Kioxia (formerly known as Toshiba Memory) is not presently very active in the high-end gaming space, it is, of course, a trusted name.

Although the Steam Deck’s original 256GB Phison E13 SSD performs surprisingly well considering its humble capacity, the BG5 is clearly faster in all situations.

gpcb recommended

Jesper Berg
Jesper Berg

I got started with PC building in the 3dfx Voodoo era somewhere back in the 1990s, and have been writing for tech publications for a bit more than a decade. In other words old enough to have lost count of the times PC gaming has been pronounced dead.

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