For most buyers in 2026, the Samsung 870 EVO is the SATA SSD to get — its dedicated DRAM cache and higher endurance hold write speeds steady where the DRAMless Crucial BX500 sags under sustained load. Choose the Crucial BX500 when price-per-gigabyte is the deciding factor and your workload is ordinary desktop use, where the difference is barely felt. Both are reliable; the 870 EVO is the better drive, the BX500 the better value.
The DRAM-vs-DRAMless divide
These two drives look interchangeable on a spec sheet — both are 2.5-inch SATA SSDs capped at the interface's ~550 MB/s ceiling — but one design choice separates them, and it explains every real-world difference: the DRAM cache. The Samsung 870 EVO includes a dedicated DRAM buffer that stores the drive's mapping tables, letting the controller find and write data quickly even under sustained load. The Crucial BX500 is DRAMless; it leans on host memory buffering and an SLC write cache instead. For short bursts the two feel identical, because the SLC cache absorbs the work. The gap only appears when you write a lot of data at once and the cache fills.
That single distinction cascades into endurance and consistency. The 870 EVO carries higher terabytes-written ratings and holds its write speed through long transfers, which is why it remains the default recommendation for anyone who copies large files, edits media, or wants a drive that ages gracefully as a system disk. The BX500 wins on cost: it routinely sells for noticeably less per gigabyte, and for booting, browsing, and launching games — the things most people actually do — it feels every bit as fast.
This comparison breaks down exactly how much the DRAM cache matters, which drive lasts longer, how they feel in daily use, when the cheaper BX500 is the smart buy, and a third option worth knowing about. By the end you will know which to put in your next upgrade.
Key takeaways
- Best overall: Samsung 870 EVO — DRAM cache keeps sustained write speeds consistent; higher endurance ratings.
- Best value: Crucial BX500 — DRAMless but cheaper per GB; indistinguishable for everyday desktop use.
- Both cap at ~550 MB/s: SATA's interface ceiling means neither approaches NVMe speeds — capacity and value are the real levers.
- Endurance rarely limits you: Both exceed a normal user's lifetime writes; TBW matters mainly for write-heavy roles.
- Third option: The SanDisk Ultra 3D is a solid middle-ground DRAM drive if the EVO is unavailable or overpriced.
Spec comparison at a glance
| Pick | DRAM cache | Endurance (TBW, 1TB class) | Sequential R/W | Price per GB |
|---|---|---|---|---|
| Samsung 870 EVO | Yes (dedicated) | ~600 TBW | ~560 / 530 MB/s | Higher |
| Crucial BX500 | No (DRAMless) | ~360 TBW | ~540 / 500 MB/s | Lower |
| SanDisk Ultra 3D | Yes (nCache) | ~400 TBW | ~560 / 530 MB/s | Middle |
The sequential numbers are close because SATA caps them all near 550 MB/s. The meaningful differences are the DRAM cache and the endurance rating, both favoring the 870 EVO — at a higher price.
How much does the DRAM cache matter for sustained writes?
For the first several gigabytes of any write, all three drives are fast because the SLC cache absorbs incoming data at full speed. The difference emerges once that cache is exhausted — during a large file copy, a game install, or a disk clone. With its DRAM buffer, the 870 EVO maintains a more consistent write rate as the transfer continues, while the DRAMless BX500 can drop to lower steady-state speeds once its SLC cache fills, because it must manage the mapping tables in slower host memory. Published reviews and sustained-write tests, including those summarized in Tom's Hardware's SSD roundups, show this pattern clearly: the drives match on bursts and diverge on long, continuous writes. If you regularly move tens of gigabytes at a time, the 870 EVO's consistency is worth paying for; if your largest write is the occasional game install, you will rarely trigger the slowdown.
Which lasts longer?
Endurance is rated in terabytes written (TBW), and the Samsung 870 EVO generally carries higher TBW figures than the budget BX500 at comparable capacities — roughly 600 TBW versus around 360 TBW at the 1TB tier. In practice, both numbers vastly exceed what a normal desktop or laptop user writes over a drive's lifetime; writing 360TB would take most people well over a decade. So while the 870 EVO is the more durable drive on paper, endurance rarely becomes the limiting factor for ordinary use. The higher rating matters most for write-heavy roles — a scratch disk for video editing, a download cache, or a drive that sees constant large writes — where the extra headroom translates to a longer service life.
Real-world feel: boot, game load, large file copies
For the everyday things people notice — Windows boot time, application launches, game level loads — the two drives feel the same. Both are limited by SATA's ceiling, and that ceiling is high enough that the bottleneck is rarely the SSD itself. Where you might feel a difference is a large, sustained file copy: moving a 50GB folder, the 870 EVO holds its pace while the BX500 may slow in the back half once its cache fills. Game loads are dominated by the interface speed both share, so they are effectively tied. The honest summary: in a blind test of normal use, you would not be able to tell them apart; only a deliberate large-write workload exposes the gap.
When is the cheaper BX500 the smarter buy?
The Crucial BX500 is the smart buy when price-per-gigabyte is your priority and your workload is ordinary — booting a PC, holding a game library, general office and browsing use. In those scenarios the DRAMless design is invisible, and the money you save can go toward more capacity, which is often the better upgrade anyway. A 1TB BX500 for the price of a smaller EVO is a genuinely good trade if you need the space. Worth knowing as a third option: the SanDisk Ultra 3D 1TB splits the difference — it includes a DRAM cache like the EVO at a price often between the two, making it a strong pick if the 870 EVO is out of stock or temporarily overpriced.
Perf-per-dollar at current street prices
On pure perf-per-dollar for everyday use, the BX500 usually wins because it costs less while delivering near-identical boot and load times. On perf-per-dollar weighted for sustained writes and longevity, the 870 EVO pulls ahead because it sustains speed and lasts longer per dollar of expected lifetime writes. The SanDisk Ultra 3D sits between them on both measures. The right answer depends on what you weight: raw value for light use favors the BX500; consistency and durability favor the EVO. For a drive you will keep for years as a system disk, the EVO's premium is easy to justify; for a cheap capacity bump, the BX500 is the value play.
Real-world numbers: the SLC cache and the sustained-write cliff
The DRAM-vs-DRAMless gap is invisible until you cross a specific threshold, and it helps to know where that threshold sits. Both drives expose a fast SLC write cache that absorbs the first chunk of any write at full SATA speed — typically tens of gigabytes depending on capacity and free space. Inside that window, the 870 EVO and the BX500 are neck and neck.
| Transfer size | Samsung 870 EVO | Crucial BX500 (DRAMless) |
|---|---|---|
| Small files / bursts | ~Full SATA speed | ~Full SATA speed |
| Up to SLC cache limit | Sustained ~530 MB/s | Sustained, near full |
| Beyond SLC cache | Holds more consistently | Drops to lower steady state |
The "cliff" is what happens past the cache. Once the SLC buffer fills during a long continuous write — cloning a drive, copying a huge video project, extracting a massive archive — the DRAMless BX500 must manage its mapping tables in slower host memory and its write rate sags, while the 870 EVO's dedicated DRAM keeps it steadier. The practical question is simply how often you write tens of gigabytes in one go. Most desktop users almost never do, which is why the BX500 feels identical in daily use; creators and anyone doing frequent large transfers hit the cliff regularly, which is why they should pay for the EVO.
A worked example: upgrading a 2018 laptop
A common scenario: a five-year-old laptop with a slow hard drive that takes a minute to boot and stutters switching apps. It has a single 2.5-inch SATA bay — no M.2 slot — so a SATA SSD is the only upgrade path, and it is transformative. Drop in a Samsung 870 EVO or, for more capacity per dollar, a Crucial BX500, and boot time falls from a minute to seconds while the whole machine feels new. The migration is painless: connect the new drive over a SATA-to-USB adapter, clone the existing install with free imaging software, then physically swap the drives. The laptop boots from the SSD with the same OS and files intact. For a machine without an M.2 slot, this $40-ish upgrade buys more perceived speed than any other component you could change.
Common SATA SSD buying mistakes
- Paying NVMe prices for SATA speed: SATA caps at ~550 MB/s no matter what. If your board has an M.2 NVMe slot, an NVMe drive is faster for similar money.
- Obsessing over endurance for light use: Both drives' TBW ratings dwarf normal lifetime writes. Do not pay a premium for endurance you will never consume.
- Ignoring capacity for marginal speed: A larger BX500 often beats a smaller EVO in real usefulness. Match capacity to your library size.
- Forgetting the cloning adapter: To migrate without a clean reinstall, you need a SATA-to-USB bridge. Budget for one.
- Assuming all "SSD" are equal: DRAMless drives slow on sustained writes. If you do heavy large-file work, pay for the DRAM cache.
When NOT to buy a SATA SSD
If your motherboard or laptop has a free M.2 NVMe slot, buy NVMe instead — it costs about the same per gigabyte now and runs three to seven times faster, with no downside in a slot that would otherwise sit empty. SATA SSDs make sense specifically when you lack an NVMe slot (older laptops and desktops), when you are filling a 2.5-inch bay for bulk capacity, or when you are upgrading a console like the PS4 that uses a SATA interface. In a modern desktop with M.2 slots free, a SATA SSD is the wrong default — reserve it for the bays and machines where NVMe is not an option.
Verdict matrix
Get the Samsung 870 EVO if...
- You copy large files, edit media, or want consistent sustained write speed.
- You want the longest endurance and a drive that ages gracefully as a system disk.
- The price premium over the BX500 is modest the day you buy.
Get the Crucial BX500 if...
- Price-per-gigabyte is your top priority and your use is ordinary desktop work.
- You would rather spend the savings on more capacity.
- You never do large sustained writes that expose the DRAMless slowdown.
Recommended pick
The Samsung 870 EVO is the recommended SATA SSD for 2026: the DRAM cache and higher endurance make it the more consistent, longer-lasting drive, and as a system disk you will keep for years, the modest premium is worth it. If your budget is tight or you mainly need capacity for a game library, the Crucial BX500 delivers near-identical everyday performance for less. To migrate your existing install to either drive, a SATA-to-USB bridge like the FIDECO adapter lets you clone the old disk before you swap it in.
Related guides
- Best SATA SSD for PS4 Pro upgrade and faster load times
- Best budget SATA SSD for a gaming boot drive
- Best SSD for retro PC IDE/SATA builds
- Best SSD for Steam Deck and ROG Ally upgrades
Citations and sources
- Samsung — 870 EVO SATA SSD — official endurance, speed, and DRAM-cache specs.
- Crucial — BX500 SSD — official BX500 specifications.
- Tom's Hardware — Best SSDs — independent SATA SSD reviews and sustained-write testing.
