The Bottom Line
- + Low power
- + Consumer workloads
- - None
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Introduction & Drive Details
KIOXIA's newest client SSD, the XG8, is an SSD we've been eagerly anticipating. Now even though it being a client SSD means it will not be clocked as high as an enthusiast-grade SSD and therefore won't be as fast overall, we still see it as something special. Why? BiCS 5 112 Layer flash is why. Here at TweakTown, we are huge fans of BiCS flash.
It's proven over the years to be the best-performing flash media, whether in the enterprise, client, or consumer space. BiCS flash is just architecturally superior as we see it. It delivers better performance with fewer layers than its competitors, proving that more layers do not necessarily equate to better performance.
Until today the only real taste of 512 Gbit BiCS 5 paired with PCIe Gen4 we've gotten has been coming from the Western Digital camp, as they are fab partners with KIOXIA and both companies have full access to BiCS flash. Having recently tested the BiCS 5 arrayed Western Digital SN850X and being blown away with its overall performance, we are naturally eager to see what KIOXIA's similarly arrayed XG8 can do. As mentioned, KIOXIA's XG8 is a client SSD meaning it is sold to OEM system builders and not through normal consumer retail channels.
Client NVMe SSDs are typically held to tighter standards of reliability and thermal thresholds than enthusiast-grade retail SSDs. This means they use less power, have more modest clock speeds, are almost always single-sided, and do not employ an integrated heat sink. Less power consumption means less heat, longer battery life, and better reliability; all attributes OEM builders want from a storage device. So, this is where a client drive like the XG8 will differ most from a retail enthusiast SSD like the SN850X, even though both are arrayed with the same flash.
Now what we expect, based on our previous experience with BiCS 4 and now BiCS 5 flash, is that KIOXIA's newest client SSD, despite its inherent performance handicap, will be able to deliver better real-world performance than even enthusiast-grade retail SSDs arrayed with 176 Layer Micron flash.
So, let's get into the review and see firsthand what KIOXIA has got cooking with its XG8 2TB and see if it can meet our high expectations.
As expected, the drive is indeed a single-sided design. The drive is arrayed with two 1TB BiCS 5 112 Layer 512 Gbit flash packages. The drive is controlled by one of KIOXIA's in-house 8-channel PCIe Gen4 x4 controllers. The XG8, as expected for any flash-based SSD with this amount of throughput features onboard DRAM.
Jon's Test System Specifications
- Motherboard: ASUS ROG Z690 HERO
- CPU: Intel Core i9-12700K - Buy from Amazon
- Cooler: Alphacool Eissturm Hurricane Copper 45 - Buy from Amazon
- RAM: Sabrent Rocket DDR5 32GB - Buy from Amazon
- Graphics Card: MSI SUPRIM X RTX 3080 12GB - Buy from Amazon
- Case: PrimoChill's Praxis Wetbench - Buy from Amazon
- Power Supply: be quiet! Dark Power Pro 12 1200W - Buy from Amazon
- OS: Microsoft Windows 11 Pro 64-bit - Buy from Amazon
Sony PlayStation 5 - M.2 Storage Expansion
PS5 Read Performance
With Sony's wildly popular PlayStation 5 console now enabled for M.2 NVMe SSDs to be used as fast storage expansion, we include results for PS5 compatible SSDs we test as a part of our reviews going forward. We are utilizing the newest PS5 hardware and software versions.
For 5,500 MB/s plus capable SSDs like the XG8 that don't have an adequately sized PS5 compatible heat sink or other SSDs where the heat sink provided doesn't fit and can be removed, we both use and recommend Sabrent's unparalleled PS5 heat sink available HERE.
We only chart SSDs that can deliver a minimum of 5,500 MB/s read, which is Sony's original recommendation. We note that with the latest PS5 software update, even SSDs that only do 4,200 MB/s no longer trigger a low-performance warning; nevertheless, we are sticking by Sony's original recommendation of 5,500 MB/s minimum read requirement.
It is very unlikely that an XG8 will find its way into a PS5 storage expansion slot, but it could handle the task quite well if it were to find its way there.
Synthetic Benchmarks: CDM, Anvil, ATTO
We are getting significantly more throughput than factory specs indicate. This is expected especially considering KIOXIA is typically conservative-minded as it relates to factory performance specifications. Random read performance is roughly 17% lower than the SN850X, which is almost assuredly related to lower power consumption and lower clock speeds.
Anvil's Storage Utilities
Anvil's read score has always been a very good synthetic indicator of real-world performance. Here KIOXIA's XG8 surprised us a bit by delivering a massive score of 11,700. That's even better than the SN850X and second only to the Platinum P41. Impressive.
Max random read IOPS are a full 10% better than factory specs indicate. We seldom see any SSD match factory specs here, so this is, again, impressive.
Sequential performance at QD4 is middle of the road for a Gen4 x 4 SSD. Roughly equivalent to Samsung's 980 Pro.
Real-World Testing: Transfers, 3DMark SSD Gaming Test, PCM10 Storage
Our 100GB data transfer test is not your ordinary 100GB of data. Ours is a crushing mix composed of more than 62K files. Overall, write performance as it applies to the consumer realm is the least important performance metric, simply because data in the consumer realm is write infrequently, read frequently. For example, how often is a game installed vs. how many times it's played?
Less power consumption is going to mean slower transfer rates. Rates are still plenty good enough as we see it, so no problem here.
3DMark SSD Gaming Test
UL's newest 3DMark SSD Gaming Test is the most comprehensive SSD gaming test ever devised. We consider it superior to testing against games themselves because, as a trace, it is much more consistent than variations that will occur between runs on the actual game itself. This test is in fact the same as running the actual game, just without the inconsistencies inherent to application testing.
In short, we believe that this is the world's best way to test an SSDs gaming prowess and accurately compare it against competing SSDs. The 3DMark SSD Gaming Test measures and scores the following:
- Loading Battlefield V from launch to the main menu.
- Loading Call of Duty Black Ops 4 from launch to the main menu.
- Loading Overwatch from launch to the main menu.
- Recording a 1080p gameplay video at 60 FPS with OBS (Open Broadcaster Software) while playing Overwatch.
- Installing The Outer Worlds from the Epic Games Launcher.
- Saving game progress in The Outer Worlds.
- Copying the Steam folder for Counter-Strike Global Offensive from an external SSD to the system drive.
Gaming is a performance metric that matters to the majority of DIY consumers, especially to the enthusiast crowd that TweakTown caters to. This chart reveals the low-power XG8 can game slightly better than Samsung's 980 Pro. Good enough, we will take it.
PCM10 Storage Tests
PCMark 10 Storage Test is the most advanced and most accurate real-world consumer storage test ever made. There are four different tests you can choose from; we run two of them.
The Full System Drive Benchmark and the Quick System Drive Benchmark. The Full System Drive Benchmark writes 204 GB of data over the duration of the test. The Quick System Drive Benchmark writes 23 GB of data over the duration of the test. These tests directly correlate with mainstream user experience.
PCMark 10 Full System Drive Benchmark
This is where the rubber meets the road as we see it. Consumer workloads. Here the XG8 clearly demonstrates, as we expected, that it can outperform any enthusiast-grade SSD arrayed with 176 Layer Micron flash. Outstanding. Performance that matters.
PCMark 10 Quick System Drive Benchmark
With this result, we feel strongly that the XG8 has shown us enough to confidently declare it to be the world's best-performing Client SSD. This is real performance; this is what BiCS is all about.
KIOXIA is the inventor of NAND flash memory, so it's no surprise that its flash-based memory products perform second to none. We find it utterly amazing that any Client SSD can run with the fastest enthusiast-grade SSDs ever made, but that's exactly what the KIOXIA XG8 has done here today. Less power, lower clocks, it doesn't matter; the core architecture of BiCS flash is so good that it can deliver class-leading real-world performance with far fewer layers than its competitors.
We rank SSDs in terms of overall user experience (performance where it matters most) as expressed by PCMark 10 storage and 3DMark gaming storage tests. We consider a user experience score of 11K or more to verify an SSD as a TweakTown Elite performer. A cumulative score of 12,738 makes the 2TB KIOXIA XG8 the seventh best-performing flash-based SSD we've tested to date. Incredible.
KIOXIA's XG8 2TB is TweakTown Elite and worthy of our highest award.
The Bottom Line
The world's best performing Client SSD.