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.



In today's review we are taking a look at the Kioxia Exceria Plus G4, which, as the name suggests is the fourth generation of the company's "Exceria Plus" solid-state-drive. What's new with the G4 is that it is Kioxia's first consumer SSD that introduces support for the PCI-Express Gen 5 interface. We reviewed the Exceria Plus G3 last year, the new G4 uses a Phison E31T controller instead of the E21 on the G3, and the NAND flash is Kioxia's 218-layer 3D TLC (vs 112-layer 3D TLC on the G3). This E31T+218L TLC combination is used on other drives, too, like the Corsair MP700 Elite, PNY CS2150 and MSI Spatium M560.

The Kioxia Exceria Plus G4 is available in capacities of 1 TB and 2 TB. While Kioxia doesn't sell these drives in the States, pricing in Europe is €112 for the 1 TB model and €190 for the 2 TB variant, including 20% VAT, which we converted to $100 and $170 respectively. Endurance for these models is set to 600 TBW and 1200 TBW, respectively. Kioxia offers a five-year warranty with the Exceria Plus G4.

Packaging

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 and two flash chips, a DRAM cache chip is not included.

Chip Component Analysis

The Phison E31 is the company's second PCI-Express 5.0 controller. It supports a four-lane configuration and four flash channels, it's a cost-optimized DRAM-less design. The controller is produced using a 7 nm process at TSMC Taiwan.


The two flash chips are Kioxia 218-layer 3D TLC NAND. Each chip has a capacity of 1 TB.

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 700 GB—partitions are resized to fill all available space on the drive.
• All drives are filled with random data to 85% 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.
• 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.
• Our real-life testing data includes performance numbers for a typical high-performance HDD, using results from a Western Digital WD Black 1 TB 7200 RPM 3.5" SATA. HDDs are significantly slower than SSDs, which is why we're not putting the result in the chart, as that would break the scaling, making the SSDs indistinguishable in comparison. Instead, we've added the HDD performance numbers in the title of each test entry.
• During these tests, M.2 drives are tested with additional active fan-cooling, to ensure thermal throttling can't happen