Three Gen4 drives within $13 of each other at 2TB, and one of them no longer has a real Amazon listing. That’s the mid-range NVMe shelf on September 28, 2026: the Samsung 990 Pro 2TB is $389.99 sold by Amazon, the 990 EVO Plus 2TB is $376.90 from a marketplace seller, and the WD Black SN850X 2TB, the drive that used to undercut both, has no buy box under the WD name. It’s still for sale. It’s called something else now, and it costs $136 more.
The 990 Pro has been in our builds since it launched, and my own rig runs a 9100 Pro, so I’ve watched this shelf reprice itself three times this year. This is the head-to-head for anyone down to these three, because the answer changes at 4TB.
Last updated: September 2026. Some links below are affiliate links. Buy through them and it helps keep the site running, at no extra cost to you. Every price here was read on the live Amazon listing on September 28, 2026, seller noted.
TLDR
At 2TB, buy the 990 Pro. It’s $389.99 sold by Amazon itself, it has DRAM, it holds about 1.4 GB/s after its cache runs out, and it’s the only first-party listing of the three at 2TB. The EVO Plus saves you $13 and gives up the DRAM, a bad trade for a media drive. The SN850X at 2TB is either a WD-branded page with no buy box or the same hardware under its new SanDisk name, the Optimus GX Pro 850X 2TB, at $525.76. Good drive, wrong price. At 4TB the order flips; more below.
| Drive | Controller / DRAM | Seq read / write | pSLC cache (2TB / 4TB) | Write after the cache | TBW (2TB / 4TB) |
|---|---|---|---|---|---|
| Samsung 990 EVO Plus | Piccolo 4-channel, no DRAM (HMB) | 7,250 / 6,300 MB/s | 226GB / 442GB | ~1.2 GB/s (2TB) | 1,200 / 2,400 |
| Samsung 990 Pro | Pascal 8-channel, LPDDR4 DRAM | 7,450 / 6,900 MB/s | 226GB / 442GB | ~1.4 GB/s (2TB), ~1.6 GB/s (4TB) | 1,200 / 2,400 |
| WD Black SN850X (= SanDisk Optimus GX Pro 850X) | WD G2 8-channel, DRAM | 7,300 / 6,600 MB/s | ~600GB / ~1,200GB | ~0.9 GB/s measured on the 1TB; 2TB and 4TB rarely leave the cache | 1,200 / 2,400 |
| Capacity | Drive | Price, September 28, 2026 | Seller |
|---|---|---|---|
| 2TB | 990 EVO Plus 2TB | $376.90 | Marketplace seller, ships from Amazon |
| 2TB | 990 Pro 2TB | $389.99 | Amazon |
| 2TB | WD Black SN850X 2TB (WD name) | no buy box; $379.99 new from a marketplace seller | Marketplace only |
| 2TB | SanDisk Optimus GX Pro 850X 2TB | $525.76 | Amazon |
| 2TB | 9100 Pro 2TB (Gen5) | $399.99 | Amazon |
| 4TB | 990 EVO Plus 4TB | $599.99 | Marketplace seller |
| 4TB | WD Black SN850X 4TB | $689.99 | Newegg Business (marketplace) |
| 4TB | 990 Pro 4TB | $989.99 | Marketplace seller |
| 4TB | SanDisk Optimus GX Pro 850X 4TB | $999.99 | Amazon |
The SN850X is now the SanDisk Optimus GX Pro 850X
The WD listing looks broken because the product moved. SanDisk, which took the flash business when it split from WD, announced the rename on January 6, 2026, and the SN850X reached retail in February as the SanDisk Optimus GX Pro 850X. Same controller, NAND, 5-year warranty, and 1,200 TBW at 2TB. The WD-branded stock is sell-through now, so the WD 2TB page shows an offers panel instead of a buy box: used units from $319 and one marketplace seller asking $379.99 for new. What Amazon sells itself is the Optimus 2TB at $525.76 as of September 28, 2026. Two wildly different prices for the SN850X means one drive under two names. The WD-branded 4TB is the exception, and it decides the 4TB section.
The $13 difference is DRAM
The 990 EVO Plus has no DRAM. Instead of an onboard chip holding the map of where every block lives, it borrows system RAM through Host Memory Buffer (HMB). On a lightly loaded desktop drive you won’t feel it. Under an editing load you can: a cache drive taking thousands of small random writes while a timeline plays, or a media drive that’s 80 percent full and juggling a fragmented map. Its 4-channel Piccolo controller is a laptop-grade part built for power efficiency, and that shows in the write numbers below.
Where the EVO Plus is fine: it runs cool bare (StorageReview saw no throttling at room temperature), it draws less power than either DRAM drive, and its hybrid PCIe 4.0 x4 / 5.0 x2 interface runs full speed in the few thin laptops with a two-lane Gen5 slot, which the other two can’t. As a boot drive, an export target, or a console drive it does the job. It isn’t the drive I’d put media on, and at $13 under the 990 Pro on September 28, 2026, the savings don’t argue otherwise.
Sustained writes: the card-dump test
All three are TLC drives with a pseudo-SLC cache in front. Write into the cache and you get the box number. Write past it in one continuous transfer and you get the native flash speed, the number you wait on when 750GB of cards lands on a drive that already holds a project.
Tom’s Hardware’s sustained write test, one copy that runs past the cache, puts the 990 Pro 2TB at about 1.4 GB/s once its 226GB cache is spent, and the 4TB at about 1.6 GB/s, since it has enough spare dies to skip folding. PCWorld’s run on the EVO Plus 2TB landed near 1.2 GB/s after the same 226GB. The SN850X plays a different game: Tom’s measured the 1TB at roughly 0.9 GB/s past the cache, the slowest floor here, but the cache is about 600GB on the 2TB and 1,200GB on the 4TB, so most card dumps never reach it. A 512GB card onto a fresh 4TB SN850X stays in cache the whole way; onto a 990 Pro it spends its last 290GB at 1.4 GB/s. Both finish in under six minutes from a fast reader; on a fresh drive this is a tie-breaker.
On a drive that’s 70 percent full it stops being a tie-breaker, because the pSLC cache shrinks with free space and the floor is what you live with: 1.4 GB/s on the 990 Pro, 1.2 on the EVO Plus, and the SN850X somewhere under 1 GB/s at 1TB (the 2TB and 4TB floors are unmeasured, so I won’t guess). None of the three throttles bare in a case with airflow: Tom’s saw the 990 Pro peak at 70 to 72 C and the SN850X at 78 C, both holding speed, so skip the heatsink SKUs for any Gen4 drive under a motherboard M.2 cover.
Enclosures and cache drives: where DRAM stops being optional
HMB is a PCIe feature. It does not work through a USB bridge chip, so a DRAM-less drive in an enclosure has no map cache at all and slows as it fills. If your 2TB might ever end up in a USB4 sled on a Mac (a good one lands around 3.0 to 3.2 GB/s), buy the 990 Pro or the SN850X and leave the EVO Plus in the motherboard. Ready-made portables are in the portable SSD guide.
The cache and scratch drive is the other place DRAM decides it. Resolve’s and Premiere’s caches are small random writes all day on a drive that fills and empties constantly, the workload HMB handles worst and the one drive the internal NVMe roles guide says never to skimp on. Media and cache drives: 990 Pro or SN850X. Boot and export: the EVO Plus is fine. One M.2 slot for everything: 990 Pro.
At 4TB the order flips
At 4TB the 990 Pro stops being the answer: Samsung’s 4TB is a marketplace-only listing at $989.99 on September 28, 2026, and a 1.6 GB/s floor doesn’t justify a $300 premium. The WD Black SN850X 4TB is $689.99, sold through Newegg Business on Amazon, with DRAM and a cache that swallows two full 512GB cards before it slows. That’s the 4TB media drive. The EVO Plus 4TB at $599.99 is the cheapest of the trio, and if the budget ends at $600 it’s a working drive. The $90 step to the SN850X gets you DRAM, a cache about three times the size, and a drive you can move into an enclosure later. For an ingest drive, spend it.
The SanDisk Optimus GX Pro 850X 4TB is Amazon’s own listing at $999.99, so the WD-branded 4TB is the same drive for $310 less while the old stock lasts; I’ll update this page when it runs out. The 990 Pro 4TB is still the better drive on the bench. It’s not $300 better.
Do not buy the plain Samsung 990
One more Samsung on the shelf carries the number and none of the pedigree. The plain Samsung 990, released July 2026, is QLC flash with no DRAM, a 3-year warranty instead of 5, and 400 TBW per terabyte, a third of the EVO Plus. Dong Knows Tech’s real-world copy test watched it fall to tens of megabytes per second once the cache filled, which turns a card dump into an afternoon. It is not an EVO Plus successor and it is not a media drive. If the label says 990 and nothing after it, put it back.
If you have a Gen5 slot, read this first
A board with a real PCIe 5.0 x4 M.2 slot changes the question, because the Samsung 9100 Pro 2TB is $399.99 sold by Amazon on September 28, 2026. Ten dollars over the 990 Pro for double the read speed on cache and scratch work and about the same write floor. It’s the drive in my own machine, and the full argument is in the 990 Pro vs 9100 Pro comparison. WD’s Gen5 answer, the SN8100, sits in the same tier. Two conditions: you need the slot (most laptops and older boards don’t have one), and Gen5 drives do need a heatsink or a motherboard M.2 cover, unlike everything else here. In a Gen4 slot the 9100 Pro runs at 990 Pro speed and you paid $10 for heat.
Should you wait for prices to drop?
The 2026 NAND spike is still in force but slowing for consumer parts: TrendForce’s third-quarter read has contract prices up 10 to 15 percent quarter over quarter, with the fourth-quarter consumer increase projected as minimal. Street prices peaked between February and April, dipped in August, and sit where the tables say as of September 28, 2026. I won’t promise a direction; this market has surprised me both ways this year. The 990 Pro 2TB at $389.99 from Amazon is a sane price in it, and a first-party listing beats a $13 marketplace discount when the return window matters. Need it for a job this month? Buy it. If the Resolve PC build is a spring project, these tables get re-read every time a price moves.
FAQ
Is a used or old-stock 990 Pro safe to buy?
Yes, with one check. Early 990 Pro units shipped with a launch firmware that chewed through reported drive health; Samsung fixed it in 1B2QJXD7. A used or old-stock drive should show that version or later in Samsung Magician; if it doesn’t, update it before you put media on it. A new 990 Pro from Amazon ships past it.
Are the WD Black SN850X and the SanDisk Optimus GX Pro 850X the same drive?
Yes, at 1TB through 4TB: same controller, NAND, cache sizing, and warranty, renamed in February 2026. The 8TB is the exception; it uses newer BiCS6 flash and a different controller and writes around 2.85 GB/s past its cache, so don’t judge the 2TB or 4TB by its numbers.
Do any of these need a heatsink?
Not the Gen4 drives. All three held full speed bare in Tom’s Hardware’s and StorageReview’s testing; a motherboard M.2 cover is plenty, and the heatsink SKUs exist for the PS5. The Gen5 9100 Pro and SN8100 are the drives that throttle without cooling.
In conclusion
At 2TB, the 990 Pro at $389.99 from Amazon is the buy, and the $13 the EVO Plus saves you isn’t worth the DRAM. At 4TB, the SN850X at $689.99 is the media drive while the WD-branded stock lasts, the EVO Plus at $599.99 is the budget fallback, and the 990 Pro 4TB is a $989.99 marketplace listing to walk past. The plain Samsung 990 is for nobody who edits. And if your board has a Gen5 slot, the whole shelf shifts $10 to the 9100 Pro.
And that’s it. My original 990 Pro write-up, now the best-SSD-for-editing roundup, stays up as the origin story; this page is the Gen4 buying answer, re-read as the old WD stock sells through. If your build has a slot or enclosure situation I didn’t cover, the comments are open.
