Western Digital WD_BLACK SN8100 4TB Heatsink vs SANDISK Optimus GX PRO 850X 1TB SSD Comparison

Western Digital WD_BLACK SN8100 4TB Heatsink and SANDISK Optimus GX PRO 850X 1TB are both solid state drives with the same Form Factor (M.2-2280) and MTBF (1,750,000 Hours). The main differences are in Capacity, Interface, Max Sequential Read and Max Sequential Write.

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Western Digital WD_BLACK SN8100 4TB Heatsink	SANDISK Optimus GX PRO 850X 1TB
Prices (Change region) In Stock Free shipping $829.99 (~~$879.99~~) $50.00 off w/ promo code: LDSF288, ends 9/6 In Stock Free shipping $849.99 In Stock $879.99 In Stock Free shipping $999.99 Show 1 more offers	Prices (Change region) In Stock $269.99 In Stock Free shipping $269.99 In Stock $269.99 In Stock Free shipping $269.99 Out of Stock Free shipping $269.99 Show 2 more offers
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Brand Western Digital	Brand SanDisk
Model WDS400T1XHM WDS400T1XHM-00CMT0	Model SDSP81100TAN-000E0 SDSP81100TAN
Release Date -	Release Date 📅 February 2026
* First availability for purchase, it may not correspond to the actual market launch date.
User reviews ★★★★☆ (23 reviews) Add a product review	User reviews Add a product review
Performance (Charts) 1st / 1748	Performance (Charts) n/a
Effective Value 90th / 336	Effective Value -
Price history View Details ►	Price history View Details ►
Price/GB $0.21	Price/GB $0.27
GB/$1 4.82	GB/$1 3.7
Series -	Series Optimus GX PRO 850X
Capacity 4000 GB	Capacity 1000 GB
Interface PCIe Gen5 x4	Interface PCIe Gen4 x4
NVME Yes	NVME Yes
Form Factor M.2-2280	Form Factor M.2-2280
NAND Flash Type -	NAND Flash Type 3D NAND TLC
Max Sequential Read Up to 14900 MB/s	Max Sequential Read Up to 7300 MB/s
Max Sequential Write Up to 14000 MB/s	Max Sequential Write Up to 6300 MB/s
MTBF 1,750,000 Hours	MTBF 1,750,000 hours