SanDisk 4TB SSD NVMe

The SanDisk Optimus GX PRO 850X is a 4TB PCIe 4.0 drive with top-tier random performance and a 99th percentile feature score. It's expensive, with US prices ranging from $850 to $1,578, and endurance is just average. Worth it if you need the capacity and speed, skip it if you're on a budget.

Sequential reads hit 7300 MB/s and writes land at 6600 MB/s. That's fast, but not quite the fastest PCIe 4.0 we've tested. The real story is random performance. 1200K random read IOPS and 1100K random write IOPS put this drive in the 96th percentile for random workloads. That means snappy app launches, quick file transfers, and smooth multitasking even when the drive is getting hammered. The TLC NAND and DRAM cache keep things consistent under sustained load. Endurance is more middle of the pack at 400 TBW, which is fine for most people but not a standout for heavy write workloads.

Against the Samsung 9100 PRO, the SanDisk holds its own on random performance but gives up some sequential speed. The Kingston FURY Renegade G5 is a closer match on paper, often at a lower price, but lacks the same feature polish. The WD_BLACK WDS800T2XHE is a strong alternative if you want similar capacity with better endurance numbers. The Crucial T710 and Seagate FireCuda 530R are both solid drives, but neither matches the Optimus GX PRO's combination of capacity and random performance. If you're building a workstation that lives and dies by random I/O, this SanDisk is the one to beat. If you're mostly doing large sequential file transfers, the Samsung or WD_BLACK might serve you better.

This is where things get tricky. US listings range from $850 to $1,578, a spread of $728 across just four listings. That's a huge gap. If you're buying in the US, shop around. Newegg has the best deal in our data at $850, and that's the one to grab if you're set on this drive. At $850, it's expensive but justifiable for a 4TB drive with this feature set. At $1,578, you're getting fleeced. European buyers see a tighter range of €1,040 to €1,115, which is more reasonable. Either way, this is a premium product with a premium price tag.

The SanDisk Optimus GX PRO 850X is a 4TB PCIe 4.0 drive that lands near the top of our database for raw capability. It's got a 99th percentile feature score, 96th percentile random performance, and 93rd percentile capacity. This is a serious workstation drive that also happens to crush gaming loads.

But here's the catch. The affordability score sits at a brutal 7th percentile. You're paying a premium for that SanDisk name and the 4TB capacity. If you need the space and the speed, it delivers. If you're just looking for a good deal, keep scrolling.

Skip this if you're building a budget gaming PC or just need a boot drive. The 7th percentile affordability score means you're paying a huge premium for capacity and features you probably won't use. If you need portable storage, look elsewhere, the 20.8 portable score is one of the worst we've seen. And if you're doing heavy sustained writes every day, the 400 TBW endurance rating might have you shopping for something more durable.

Buy this if you need 4TB of fast, reliable storage in a single slot and you're willing to pay for it. The Optimus GX PRO 850X is a workstation workhorse with best-in-class features and random performance that keeps everything feeling instant. It's overkill for casual gaming rigs and a bad value for budget builds. But for video editors, data analysts, or anyone juggling massive projects, this drive earns its keep.