Feed: AnandTech
Feed Link: https://www.anandtech.com
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Title: Western Digital Adds 8TB Model to Popular High-End SN850X SSD Drive
Family

Date: Tue, 16 Jul 2024 17:30:00 EDT
Link: https://www.anandtech.com/show/21472/western-...

Western Digital has quietly introduced an 8 TB version of its high-end SN850X
SSD, doubling the top capacity of the well-regarded drive family. The new
drive offers performance on par with other members of the range, but with
twice as much capacity as the previous top-end model - and with a sizable
price premium to go with its newfound capacity.

Western Digital introduced its WD_Black SN850X SSDs in the summer of 2022,
releasing single-sided 1 TB and 2 TB models, along with a double-sided 4 TB
model. But now almost two years down the line, the company has seen it fit to
introduce the even higher capacity 8 TB model to serve as their flagship PCIe
4.0 SSD, and keep with the times of NAND prices and SSD capacity demands.

Like the other SN850X models, WD is using their in-house, 4-channel
controller for the new 8 TB model, which sports a PCIe 4.0 x4 interface. And
being that this is a high-end SSD, the controller is paired with DRAM (DDR4)
for page index caching, though WD doesn't disclose how much DRAM is on any
given model. On the NAND front, WD is apparently still using their BiCS 5
112L NAND here, which means we're looking at 4x 2 TB NAND chips, each with 16
1Tbit TLC dies on-board, twice as many dies as were used on the NAND chips
for the 4 TB model.

The peak read speed of the new 8TB model is 7,200 MB/sec, which is actually a
smidge below the performance the 4 TB and 2 TB models due to the overhead
from the additional NAND dies. Meanwhile peak sequential write speeds remain
at 6,600 MB/sec, while 4K random write performance maxes out at 1200K IOPS
for both reads and writes. It goes without saying that this is a step below
the performance of the market flagship PCIe 5.0 SSDs available today, but
it's going to be a bit longer until anyone else besides Phison is shipping a
PCIe 5.0 controller - never mind the fact that these drives aren't available
in 8 TB capacities.

The 8 TB SN850X also keeps the same drive endurance progression as the rest
of the SN850X family. In this case, double the NAND brings double the
endurance of the 4 TB model, for an overall endurance of 4800 terabytes
written (TBW). Or in terms of drive writes per day, this is the same 0.33
rating as the other SN850X drives.

WD_Back SN850X SSD Specifications Capacity 8 TB 4 TB 2 TB 1 TB Controller WD
In-House: 4 Channel, DRAM (DDR4) NAND Flash WD BiCS 5 TLC Form-Factor,
Interface Double-Sided M.2-2280
PCIe 4.0 x4, NVMe Single-Sided M.2-2280
PCIe 4.0 x4, NVMe Sequential Read 7200 MB/s 7300 MB/s 7300 MB/s 7300 MB/s
Sequential Write 6600 MB/s 6600 MB/s 6600 MB/s 6300 MB/s Random Read IOPS
1200K 1200K 1200K 800K Random Write IOPS 1200K 1100K 1100K 1100K SLC Caching
Yes TCG Opal Encryption 2.01 Warranty 5 Years Write Endurance 4800 TBW
0.33 DWPD 2400 TBW
0.33 DWPD 1200 TBW
0.33 DWPD 600 TBW
0.33 DWPD MSRP (No Heatsink) $850 $260 $140 $85

Western Digital's WD_Black SN850X is available both with and without aluminum
heatsink. The version without a heatsink aimed at laptops and BYOC setups
costs $849.99, whereas a version with an aluminum heat spreader comes at
$899.99. In both cases the 8 TB drive carries a significant price premium
over the existing 4 TB model, which is readily available for $259.99.

This kind of price premium is unfortunately typical for 8 TB drives, and will
likely remain so until both supply and demand for the high-capacity drives
picks up to bring prices down. Still, with rival drives such as Corsair's
MP600 Pro XT 8 TB and Sabrent's Rocket 4 Plus 8 TB going for $965.99 and
$1,199.90 respectively, the introduction of the 8 TB SN850X is definitely
pushing high-capacity M.2 SSD prices down, albeit slowly. So for systems with
multiple M.2 slots, at least, the sweet spot on drive pricing is still to get
two 4 TB SSDs.

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