Shop
  • Deals
  • Deal checker
  • Black Friday
  • Buying guides
  • Brands
  • Stores
Travel
  • Flight deals
  • Hotel deals
Company
  • Research
  • Press
  • deal.ai apps
Black Friday 2026
  • Walmart
  • Best Buy
  • Target
  • TVs
  • Laptops
  • Headphones
  • Apple
  • Gaming
  • Vacuums
  • Kitchen
  • Toys
  • Smartwatches
  • Tablets
  • Furniture
  • Mattresses
© Deal.ai Inc.
TermsPrivacy
Deal.ai › SanDisk › Hard Drives
SANDISK
SANDISK Optimus GX PRO 850X 4TB Internal SSD

SANDISK Optimus GX PRO 850X 4TB Internal SSD

Best price now

$849.99at Best BuyChecked 11 h ago

Compared across 3 stores. Prices are checked against each store and labelled with when. Store links may earn us a commission. Price via Klarna.

Visit Best Buy

Ask our agent about this product

It checks today's price at every store, compares the alternatives and answers in about a minute.

Enter to send, Shift+Enter for a new line

Price facts

  • Lowest price today: $849.99 at Best Buy (checked Nov 10, 2026).
  • Checked at 3 stores.

Our take on the SANDISK Optimus GX PRO 850X 4TB Internal SSD

The SanDisk Optimus GX PRO 850X is a 4TB M.2 2280 NVMe drive on PCIe Gen4 x4, built on 3D TLC flash with a rated sequential write speed of 7300 MB/s. It is aimed at people who need a lot of fast storage in one slot: game libraries, video projects and large working files. Against other Gen4 drives it trades on capacity and sustained write speed rather than extras like a heatsink or bundled software. It suits desktops and newer laptops with a free full-length M.2 slot and good airflow.

Best forGamers with large librariesVideo editors and creatorsDesktop builds with a free M.2 slotLaptops that support full-length Gen4 drives
Pros
  • 4TB in a single M.2 2280 slot
  • PCIe Gen4 x4 with rated 7300 MB/s sequential write
  • 3D TLC flash rather than QLC
  • NVMe interface works with modern desktops and laptops
  • High capacity suits game and media libraries
Cons
  • No heatsink included, so sustained writes can throttle without airflow
  • Gen4 speeds need a Gen4-capable slot to be fully used
  • TLC endurance is good but not enterprise-grade
  • Single-sided or double-sided layout is not stated, so check laptop clearance

SANDISK Optimus GX PRO 850X 4TB Internal SSD prices at every store

  • Best BuyNew

    In stock

    $849.99Free shippingChecked 11 h ago
    Visit Best Buy
  • NeweggNew

    In stock

    $849.99Free shippingChecked 11 h ago
    Visit Newegg
  • AntonlineNew

    In stock

    $1,086.73Free shippingChecked 11 h ago
    Visit Antonline

Store links may earn us a commission. Some prices via Klarna.

SANDISK Optimus GX PRO 850X 4TB Internal SSD price history

Lowest price we've seen: $849.99 on Nov 10 at Best Buy. Tracked across 3 stores since Nov 10.

Specifications

Form Factor
M.2Source
Type
SSDSource
M.2 Form Factor
2280Source
Size (GB)
4000Source
Flash Memory
3D TLCSource
Sequential Write (MB/s)
7300Source
Interface
PCIe Gen4 x4 NVMeSource

Questions and answers

Is this drive fast enough for gaming and video editing?
Yes. Its rated 7300 MB/s sequential write and Gen4 interface put it in the fast NVMe class, which suits large game installs and 4K video work. Real-world speed depends on your slot and cooling.
Does it come with a heatsink?
No heatsink is listed. On a desktop, use your motherboard's M.2 heatsink or good case airflow to avoid throttling during long writes.
Will it fit my laptop?
It is a standard M.2 2280 drive, so it fits laptops with a full-length M.2 slot that supports PCIe Gen4 or Gen3. Check clearance and whether the slot accepts double-sided drives before buying.
Is 4TB enough for a game library?
It holds a large library, but modern games can run 100GB or more each, so plan for roughly a few dozen big titles. It also leaves room for recordings and project files.
Does it work in a PCIe Gen3 slot?
Yes, it is backward compatible, but it will run at Gen3 speeds rather than its rated Gen4 figures. You only get the full speed in a Gen4 x4 slot.
Is TLC flash better than QLC here?
TLC generally sustains write speed better and lasts longer than QLC at the same capacity. That matters for large file transfers and heavy use.
Where is the SANDISK Optimus GX PRO 850X 4TB Internal SSD cheapest?
At Best Buy, for $849.99, as of our latest check.
Where can I buy the SANDISK Optimus GX PRO 850X 4TB Internal SSD?
3 stores we checked sell it, including Best Buy, Newegg, Antonline.

Stores we've priced the SANDISK Optimus GX PRO 850X 4TB Internal SSD at

  • Best Buy deals and prices
  • Newegg deals and prices

More from SanDisk

  • S
    SanDisk Extreme Portable 4TB USB-C NVMe SSD
    SanDisk Extreme Portable 4TB USB-C NVMe SSD
  • S
    SanDisk SN7100 2TB SSD M.2
    SanDisk SN7100 2TB SSD M.2
  • S
    SanDisk Optimus 5100
    SanDisk Optimus 5100
  • W
    WD_BLACK 1TB SN7100 NVMe Internal SSD
    WD_BLACK 1TB SN7100 NVMe Internal SSD
  • S
    SanDisk Z400s Solid State Drive SD8S
    SanDisk Z400s Solid State Drive SD8S
  • S
    SANDISK Optimus GX 7100 1TB NVMe Internal Gaming SSD
    SANDISK Optimus GX 7100 1TB NVMe Internal Gaming SSD
  • S
    SanDisk Extreme 64 GB microSDXC A2 V30
    SanDisk Extreme 64 GB microSDXC A2 V30
  • S
    Sandisk WD Red SN700 Series 1TB M.2 2280 M-Key PCIe NVMe SSD Drive, single-sided (WDS100T1R0C)
    Sandisk WD Red SN700 Series 1TB M.2 2280 M-Key PCIe NVMe SSD Drive, single-sided (WDS100T1R0C)
All SanDisk deals and products →