here!
I’m your shopping assistant for PC builds, upgrades, and everything tech.
Got questions? Ask away!
Start a conversation
- Free 92-day Returns
$849.99
Add to PC build list
Login to Make an Offer
Sold by Newegg
Shipped by Newegg
Best Sellers
- $940.00
- + FREE SHIPPING
Top Rated- $899.00
- + $39.99 Shipping
- $939.99
- + $39.99 Shipping
SANDISK 4TB Optimus™ GX PRO 850X PCIe® 4.0 x4 M.2 2280 NVMe™ SSD - SDSP81400TAN-000E0
- CHAMPION YOUR GAME SESSION AND CREATIVE WORKFLOW. Boasting PCIe® Gen 4.0 Sequential Read/Write speeds up to 7,300/6,600MB/s (2TB and 4TB models), your SSD enhances your game sessions and your creative workflow.
- STAY IN THE GAME. Experience seamless game sessions and smooth multitasking with Random Read/Write speeds up to 1.2M/1.2M IOPS (8TB model) and integrated SANDISK® nCache™ 4.0 technology. Supports Microsoft® DirectStorage games.
- NO NEED TO DELETE. Stop deleting to make room for more games or applications. With capacities up to 8TB and trusted SANDISK® BiCS TLC 3D NAND, you’ll have room for more.
- DESIGNED WITH THE CREATOR IN MIND. With up to 4,800 TBW (8TB model) endurance rating, your drive stays by your side. Help protect your digital assets with TCG Opal v2.01 data-at-rest encryption.
- YOU CAN DO MORE WITH SANDISK® SOFTWARE. Download the SANDISK® Dashboard application (Windows® only) to help keep your drive in peak shape. Or turn on Game Mode to transform your gaming experience.
- REST EASY. Your hard work is covered with Sandisk’s 5-year limited warranty for peace of mind
+
+
Overview
Specs
Reviews
See all Q & A 
Any questions? Ask CelesteSM will help you find out quickly.
Try me now
Overview
The SANDISK Optimus™ GX PRO 850X is a 4TB internal solid state drive for desktop and notebook systems with an M.2 2280 slot and PCI-Express 4.0 x4 interface. It combines NVMe 1.4 performance, TLC 3D NAND, and high-capacity storage for gaming, applications, and creative workflows.
Key Features
- 4TB capacity for storing games, applications, and creative files
- PCIe® 4.0 x4 interface with NVMe 1.4 protocol
- SanDisk BiCS TLC 3D NAND and SANDISK® nCache™ 4.0 technology
- TCG Opal v2.01 data-at-rest encryption
- SANDISK® Dashboard application for Windows® with Game Mode
Performance
Sequential performance reaches up to 7,300 MBps read and 6,600 MBps write. 4KB random performance reaches up to 1,200,000 IOPS read and 1,100,000 IOPS write. The drive is rated for up to 2,400TB written, with average active power of 8.0W for read and 7.2W for write, plus 5mW idle power.
Design
The drive uses an M.2 2280-D5-M form factor and is supplied without a heatsink. It measures 80mm deep, 22mm wide, and 3.88mm high, with a listed weight of 8.6g.
Connectivity & Compatibility
This internal SSD connects through a PCI-Express 4.0 x4 interface and uses the NVMe 1.4 protocol. Its M.2 2280-D5-M form factor is intended for systems with a compatible M.2 slot. The original listing also identifies support for Microsoft® DirectStorage games.
Reliability & Durability
The drive has a listed MTBF of 1,750,000 hours and an endurance rating of 2,400TB written. Operating temperature is 0°C to +85°C, while storage temperature is -40°C to +85°C. Shock resistance is rated at 1,500G at 0.5ms half-sine. Operating vibration is 5 gRMS at 10–2000Hz across 3 axes, and non-operating vibration is 4.9 gRMS at 7–800Hz across 3 axes. TCG Opal v2.01 data-at-rest encryption helps protect stored data.
Software & Tools
The SANDISK® Dashboard application is available for Windows® and provides drive management tools. The original listing also identifies Game Mode as an available software feature.
Specifications
- Brand: SanDisk
- Series: Optimus GX PRO 850X
- Model: SDSP81400TAN-000E0
- Device Type: Internal Solid State Drive (SSD)
- Capacity: 4TB
- Form Factor: M.2 2280-D5-M
- Memory Components: 3D NAND TLC
- Interface: PCI-Express 4.0 x4
- Protocol: NVMe 1.4
- Max Sequential Read: Up to 7300 MBps
- Max Sequential Write: Up to 6600 MBps
- 4KB Random Read: Up to 1,200,000 IOPS
- 4KB Random Write: Up to 1,100,000 IOPS
- Terabytes Written (TBW): 2400TB
- MTBF: 1,750,000 hours
- Heatsink: Without heatsink
- Idle Power: 5mW
- Average Active Power Read: 8.0W
- Average Active Power Write: 7.2W
- Operating Temperature: 0°C to +85°C
- Storage Temperature: -40°C to +85°C
- Height: 3.88mm
- Width: 22mm
- Depth: 80mm
- Weight: 8.6g
Warranty & Returns
Warranty, Returns, And Additional Information
Warranty
- Limited Warranty period (parts): 5 years
- Limited Warranty period (labor): 5 years
- Read full details
Return Policies
- Return for refund until: January 31, 2026
- Return for replacement until: January 31, 2026
- This item is covered by Newegg.com's Extended Holiday Return Policy.
- Read full return policy for details.
We want to ensure your holiday shopping this year is hassle-free. That’s why we’re automatically extending our return policies on almost every product! For purchases placed between November 1st, 2025 and December 31, 2025 you will have until January 31, 2026 to return your product.
Manufacturer Contact Info
- Manufacturer Product Page
- Manufacturer Website
- Support Phone: 1-866-726-3475
- Support Website
- View other products from SanDisk
LOADING...
LOADING...
The SanDisk Optimus GX PRO 850X is a 4TB M.2 2280 PCIe 4.0 x4 NVMe SSD with sequential speeds up to 7,300 MB/s read and 6,600 MB/s write, suited to PC gamers and creators who want fast storage for games, applications, and active projects.
Recommended For
- PC gamers expanding a modern PCIe 4.0 gaming library who want 4TB in one M.2 drive and faster game loading, rather than adding multiple smaller drives.
- Video editors and digital-content creators working with large project files who want a high-capacity internal drive for active media and fast file access.
- Builders of PCIe 4.0 gaming or creator desktops with an M.2 2280 slot and motherboard cooling who want a fast TLC SSD for a large games or project drive.
- Users who regularly install or move large applications and media libraries and prefer a single 4TB internal drive over frequent storage cleanup.
Real-World Use Scenarios
- When a PC gamer keeps several large games installed at once, the 4TB capacity leaves room for a larger library without frequent uninstalling; games stored on the drive can also benefit from fast level loading.
- For a gaming-PC storage upgrade, users can move games and everyday applications onto the SSD to reduce storage-related waiting when launching games or opening programs; actual load times also depend on the PC and software.
- When a creator works with large video, photo, or other media projects, the drive provides local space for project files and a fast destination for large transfers; it can help keep storage from slowing file handling, but does not replace CPU or GPU work during editing or rendering.
- For someone building or upgrading a compatible desktop PC, the M.2 NVMe drive can serve as a main or secondary internal drive for games, applications, and frequently used files, consolidating a substantial amount of storage in one slot.
- When installing or moving large games and creative-project folders, users have fast local storage for those files; transfer speed will still depend on the source drive, connection, and workload.
Spec Summary
| Attribute | Value |
|---|---|
| Best For | 4TB internal storage for gaming, business, and personal use |
| Capacity | 4TB |
| Interface And Form Factor | M.2 2280 internal SSD with PCIe 4.0 x4 and NVMe 1.4 |
| Read Write Performance | Sequential read up to 7,300 MB/s and write up to 6,600 MB/s; 4KB random read up to 1,200,000 IOPS and write up to 1,100,000 IOPS |
| NAND And Reliability | 3D NAND TLC, rated for 2,400TB written and 1,750,000 hours MTBF |
| Power And Operating Conditions | 5mW idle power; average active power of 8.0W for reads and 7.2W for writes; operating temperature 0°C to 85°C and storage temperature -40°C to 85°C |
| Physical Specifications | 80 × 22 × 3.88mm; weighs 8.6g; no heatsink included; rated for 1,500G shock at 0.5ms and specified operating and non-operating vibration resistance |
| Device Compatibility | Listed for desktop and laptop systems, and compatible with Sony PlayStation 5 and Microsoft Xbox Series S |
| Model Identifiers | SanDisk Optimus GX PRO 850X; model SDSP81400TAN-000E0 |
Reference Q&A
Q: Is the SanDisk Optimus GX PRO 850X 4TB different from the WD_BLACK SN850X 4TB?
A: SanDisk positions the Optimus GX PRO 850X as the successor brand for the WD_BLACK SN850X. Their listed 4TB sequential read/write ratings are the same: up to 7,300/6,600 MB/s. Choose between them based on current price, availability, warranty terms, and whether you want the specific model or branding; check the exact SKU and heatsink configuration before buying.
Q: Should I get the 4TB Optimus GX PRO 850X or the Samsung 990 PRO 4TB?
A: Both are high-performance PCIe 4.0 NVMe SSDs. Samsung rates the 990 PRO 4TB slightly higher at up to 7,450 MB/s read and 6,900 MB/s write; SanDisk rates this 850X at up to 7,300/6,600 MB/s. Choose the Samsung if its slightly higher rated peak speeds matter to your workload; choose the SanDisk if its price, availability, or software fits your setup better. Compare current prices and heatsink versions before deciding.
Q: Is the 4TB GX PRO 850X worth choosing over the 2TB version?
A: Choose the 4TB model if you need room for a larger game library or large project files: it doubles capacity and rated endurance to 2,400 TBW, while retaining the same up-to-7,300/6,600 MB/s sequential ratings. The 2TB model is a better fit if it provides enough space and costs less; its rated endurance is 1,200 TBW.
Q: Should I buy the 4TB GX PRO 850X with a heatsink or without one?
A: Choose the heatsink version if your system lacks an M.2 heatsink and its clearance supports the drive’s heatsink. The bare version is suitable when your motherboard or device already provides compatible M.2 cooling. SanDisk lists both configurations, so verify the model number and physical clearance before ordering.
Q: Should I choose the 4TB or 8TB GX PRO 850X?
A: Choose 8TB if you need more capacity on a single drive; SanDisk rates it for up to 4,800 TBW versus 2,400 TBW for the 4TB model. The 4TB version has a slightly higher rated sequential read speed—up to 7,300 MB/s versus 7,200 MB/s—while both are rated up to 6,600 MB/s sequential write. Pick based on capacity needs rather than expecting the 8TB model to have a higher listed sequential speed.
Q: Will this SSD fit my laptop or desktop?
A: It is an M.2 2280 NVMe PCIe 4.0 x4 drive. It is suitable only for systems with a compatible M.2 NVMe slot and enough physical clearance; check your device or motherboard specifications before buying. The drive has no included heatsink, which may also matter in space-constrained systems.
Q: Does this SSD come with a heatsink?
A: No. This model is listed without a heatsink. Check whether your system provides M.2 cooling or requires a separately purchased, compatible heatsink, and confirm that it will fit before installation.
Q: Can I use this SSD as storage in a PS5?
A: Its 4TB capacity, M.2 2280 form factor, and PCIe 4.0 x4 interface align with common PS5 expansion-drive requirements, but the drive does not include a heatsink. Confirm the requirements for your console model and add a compatible heatsink before installation.
Q: Is this SSD suitable for gaming and large creative projects?
A: It is a 4TB internal SSD rated for sequential reads up to 7,300 MB/s and writes up to 6,600 MB/s, making it suitable for systems with a compatible PCIe 4.0 x4 NVMe slot when you want substantial space for games, applications, or large work files. Actual performance depends on the host system and workload.
Q: Is 4TB overkill for a gaming PC?
A: It depends on how many large games and applications you keep installed. A Reddit discussion raises whether 4TB is necessary and notes that some games can take substantial space. This drive provides 4TB, but the supplied specifications do not establish that every gaming setup needs that capacity.
Q: Is the 4TB Optimus GX PRO 850X worth buying over a cheaper SSD?
A: It is most relevant if you want 4TB capacity and PCIe 4.0 performance of up to 7,300 MB/s read and 6,600 MB/s write. Whether it is worth the extra cost depends on the prices and warranty available to you; Reddit discussions compare it with less expensive drives and question the value of paying more.
Q: Is the SanDisk Optimus GX PRO 850X the same as the WD_BLACK SN850X, and why might their prices differ?
A: Reddit users compare the two models and ask about their price difference. Compare the exact capacity, heatsink configuration, seller, warranty, and current price before choosing; the supplied product information identifies this 4TB model as a PCIe 4.0 drive without a heatsink.