Introduction

The Kioxia brand was established around 2018/2019, after Toshiba sold its SSD and memory branch "Toshiba Memory." The company now produces flash memory for its own products, but also WD and Sandisk. Part of the original Toshiba SSD business was formed in 2014, when Toshiba bought the famous OCZ brand. Kioxia later acquired the SSD maker Lite-On. Unfortunately, first party Kioxia SSD products are not available in the United States.


The Kioxia Exceria Pro G2 is the company's new PCI-Express Gen 5 flagship for the consumer market and the successor to the Gen 4 Exceria Pro. It launched in December last year and we finally got a sample. Kioxia rates our 4 TB unit at 14.9 GB/s sequential read and 13.7 GB/s sequential write, with up to 2.3 million random read IOPS and 1.95 million write IOPS.

The Kioxia Exceria Pro G2 is built around the new Silicon Motion SM2508 controller, which focuses on efficiency to help keep thermal output in check. This is the same controller we've seen in several other recent Gen 5 drives such as the WD Black SN8100, Acer Predator GM9000, Kingston Fury Renegade, and Lexar NM1090.

As NAND flash, Kioxia's own BiCS8 218-layer TLC NAND flash is used, configured in a single-sided design with just two NAND packages, despite the massive 4 TB capacity. The Exceria Pro G2 also includes a 4 GB LPDDR4X DRAM cache, ensuring smooth handling of the SSD's internal mapping tables and sustained performance under heavy workloads.

Since Kioxia doesn't sell the drive in the US, we're going by European pricing. The Exceria Pro G2 is available in capacities of 1 TB (€190), 2 TB (€350) and 4 TB (€630). Converting to USD without tax we get $185, $340 and $610. The endurance is set to 600 TBW, 1200 TBW and 2400 TBW respectively. Kioxia includes a five-year warranty with Exceria Pro G2 SSD.

The Drive

The drive is designed for the M.2 2280 form factor, which makes it 22 mm wide and 80 mm long.


PCI-Express 5.0 x4 is used as the host interface to the rest of the system, which doubles the theoretical bandwidth compared to PCIe 4.0 x4.


On the PCB you'll find the controller, one DRAM chip and two flash chips. Everything sits on the front side—the back of the card is completely clean, which makes this a single-sided drive, with maximum compatibility, even at 4 TB.


Kioxia's label has a copper-colored component on the back, but it doesn't look like the typical heat spreader copper. Usually those have some noticeable thickness, whereas here there is no added thickness at all; it doesn't feel metallic either, and bends very easily.

Chip Component Analysis

The Silicon Motion Technology SM2508 controller is the company's first PCI-Express 5.0 controller for consumer applications. It supports PCIe 5.0 x4 and runs with eight flash channels at 3600 MT/s. SMI fabricates the controller using a 6 nanometer process at TSMC Taiwan.


The two flash chips are Kioxia BiCS8 3D TLC NAND with 218 layers, marked TH58LKT4X48BAEG. Each chip has a capacity of 2 TB.


The DRAM chip is a 4 GB SK hynix LPDDR4X-4266 module. That's the classic 1 GB of DRAM per 1 TB of flash ratio, which gives the controller plenty of room to hold the mapping tables in memory, so it never has to go looking for address translations on the flash itself.

Test Setup

Synthetic Testing

• Tests are run with a 20-second-long warm-up time (result recording starts at second 21).
• Between each test, the drive is left idle for 60 seconds, to allow it to flush and reorganize its internal data.
• All write requests contain random, incompressible data.
• Disk cache is flushed between all tests.
• During these tests, M.2 drives are tested with additional active fan-cooling, to ensure thermal throttling can't happen.

Real-life Testing

• After initial configuration and installation, a disk image is created; it is used to test every drive.
• Automated updates are disabled for the OS and all programs. This ensures that—for every review—each drive uses the same settings, without interference from previous testing.
• Our disk image consumes around 1.5 TB—partitions are resized to fill all available space on the drive.
• All drives are filled with random data to 80% of their capacity. This is intentional, to run the drive in realistic operating conditions—nobody uses a nearly-empty SSD in their system. It also puts additional stress on the pseudo-SLC cache subsystem, because there is less free NAND space to work with.
• 1 TB drives are tested in three independent runs, applications first, then 2x games, each filled to 80% capacity, with secure erase between.
• Partitions are aligned properly.
• Disk cache is flushed between all tests.
• In order to minimize random variation, each real-life performance test is run several times, with reboots between tests to minimize the impact of disk cache.
• All application benchmarks run the actual application and do not replay any disk traces.
• During these tests, M.2 drives are running with additional active fan cooling, to entirely prevent thermal throttling.

Comparison Drives

We compare the tested drive to a wide selection of SSDs currently available on the market. Besides popular drives, our focus is also on including common controller and flash type combinations.