Everything you need to know about the Samsung 980 happens around the 170 GB mark of a big copy. Before that point the drive flies. After it, the speed falls by about three quarters and stays there until the job ends.
For most people that will never matter, because few of us write 170 GB in one go. For someone planning to put this drive in a USB enclosure for backups or video work, it is the main thing to understand.
Product image from the Amazon listing.
Owner reports on this exact drive are scarce, so most numbers below come from reviewers’ tests. Please do not mix this drive up with the 980 PRO. The PRO is a faster PCIe 4.0 product with its own reputation, and owner stories about it don’t apply here.
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A Budget Drive With No DRAM
The plain 980 is a PCIe 3.0 NVMe drive, and Samsung built it to a price. The 1TB version launched in March 2021 at about $130, according to PCWorld.
The key design choice is that it has no DRAM chip of its own. PC Perspective explains that it uses Host Memory Buffer instead, taking 64 MB of system memory across the PCIe link. That keeps cost down, and inside a PC it works well. The review calls the drive “a value-oriented option” and says it stays very competitive outside demanding, write-heavy jobs.
To make up for the missing DRAM, Samsung leans on a cache. A part of the flash acts as a fast buffer, and Samsung calls this Intelligent TurboWrite 2.0. KitGuru says “the default TurboWrite region of the 1TB drive is 160GB”, which is over three times the size in the older 970 EVO. It also lists a five-year warranty and scored the drive 8 out of 10.
Product image from the Amazon listing.
The Long Write
Here is where the reviews line up nicely. The SSD Review moved 473 GB of video files and wrote that “an average of 1.8GB/s transfer speed was maintained for 171GB before it dropped to 400MB/s.” PCWorld ran a 450 GB single-file write and saw the same cliff at around 170 GB. It measured about 475 MB/s beyond the cache, and 415 MB/s with the drive half full.
Two separate tests landed on the same cliff, so I trust this number. On a 1TB drive you get roughly 170 GB at full speed, and then 400 to 475 MB/s.
Let me put that in time. By my arithmetic, The SSD Review’s 473 GB job would take about a minute and a half for the first 171 GB, and then around 12 or 13 minutes for the rest. That is slower than a good drive with DRAM, and much faster than any hard disk. PCWorld’s reviewer summed it up well: “If your needs are simple this may not be an issue, but other drives don’t have this limitation.”
The good news is that the cache comes back. Tom’s Hardware suggested that it recovers quickly, and The SSD Review saw only a small drop when testing again at half full, saying “we don’t find this anything to be concerned about.” So a daily backup of 30 or 40 GB should stay in the fast zone, as long as the drive has time to rest between runs.
Fill level matters a little too. PCWorld’s half-full result was the lowest number here, so keep some free space if you want the best from it.
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Product image from the Amazon listing.
Heat Reports Don’t Quite Agree
Samsung talks a lot about thermals. PC Perspective lists a nickel-coated controller, a heat spreader label and Dynamic Thermal Guard, and Samsung claims better thermal control than the 970 EVO. Tom’s Hardware reported little trouble with throttling or temperature, though that comment appears to concern the 500 GB model.
Real owners have a different story at least some of the time. In an Unraid forum thread from November 2022, an owner using a 1TB 980 as a cache drive got repeated overheating alerts, with a warning level of 84°C. Moving it to an ASUS board with a better slot did not stop them. The same owner said a Samsung 970 in the same enclosure never overheated. A forum moderator called it a known issue with that device and pointed to a separate bug report with a possible workaround. The thread does not show whether that worked.
One server owner is not a trend, and an alert does not prove the drive was truly at that temperature. I would still note it. Unraid cache drives run under steady write loads, which is the same kind of work you might plan for an external box.
No proper temperature test of the 1TB model turned up, so I will not give you a number.
In a USB Enclosure
This is the use many of our readers have in mind, and the evidence is weakest here. I found no test of the 980 in a USB enclosure. Every lab result above comes from inside a PC.
I can still tell you what to think about. A 10 Gbps enclosure tops out around 1,000 MB/s, so you lose the drive’s full burst speed from the start. The cache would still last for about the same amount of data, and then you would drop to the same 400-something range. Filling that cache at 1,000 MB/s would take close to three minutes. So the enclosure makes the first part slower and leaves the second part about the same.
The bigger question is the missing DRAM. PC Perspective describes the Host Memory Buffer as memory taken over PCIe, and an enclosure’s USB bridge sits in the way. As far as I can tell, the drive would run without it. Samsung says “the SSD can operate even without its own DRAM”, which is about the design in general. Nobody I read measured what a USB bridge changes. I would expect small random work to suffer more than big video files, but that is my guess.
Heat is the other worry. A slim enclosure has less air than a PC case, and the Unraid report above shows that this drive can raise alerts even on a motherboard. Choose an aluminum enclosure with a thermal pad, and check that the pad’s protective film is removed. If you see drops during long copies, try a shorter job first and check for heat before you blame the SSD.
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Also think about the Mac side. I have no Mac owner report on this drive to rely on, so test it yourself with a full copy before you trust it with a backup. And run a real restore, not only a copy. No reviewer I read tried that.
Where I Land on the 980
For a Windows PC that needs a simple, cheap second drive for games, documents or everyday projects, I like the 980. Its long-write weakness only shows up on jobs most people rarely run, and its cache recovers well. The five-year warranty helps.
For an external build used for large video work or big nightly backups, I would look at a drive with DRAM. You are paying to avoid that 400 MB/s floor. A heavy workload will also punish the heat weakness more often. Skip the 980 too if you need PCIe 4.0 speed, because it was never built for that.
For everyday storage in a working PC, the Samsung 980 NVMe SSD 1TB is a sensible pick, and I would only think twice if your typical copy runs far past 170 GB. This is an affiliate link. As an Amazon Associate I earn from qualifying purchases.
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