An NVMe SSD is the fastest type of storage you can put in a computer, but it’s also more temperamental than the old spinning hard drives they replaced. Lately my system hasn’t felt as fast as when I first set it up. I noticed slightly longer loading screens at first, but slow file transfers between my PC and the NAS really took care of the problem – it was almost a full SSD.
I stuffed the NVMe SSD because I wanted to use every last gigabyte
All these gigabytes cannot be left idle
My gaming system has a 2TB NVMe SSD. I know that sounds like a lot, and given how expensive the market has been lately, it kind of is, but the truth is that modern games take up a ton of space.
Starfield it takes up about 140GB on its own, and I have several other games on my computer that take up about the same amount of space. Add in some of my personal and work files, extra backups, and some random stuff, and it’s easy to see how I manage to fill up my NVMe in no time. Oh, and let’s not forget that the 2TB NVMe SSD actually only provides 1.81TB of data once installed in the system.
Since NVMe storage is more expensive than ever, I wanted to make the most of itso I only kept about 10% free space on my disk, which is sometimes said to be the minimum Keep your NVMe healthy. This is a general rule of thumb, and I’ll explain shortly why not all NVMs are built the same.
I didn’t notice the slowdown in regular tasks as much as it happened gradually. But after setting up a NAS recentlyI started transferring a lot of files between it and my computer on a fairly regular basis. This periodically brought my NVMe closer to 5% free space instead of 10%, and I couldn’t help but notice that even though the NAS was using the same gigabit Ethernet and external hard drive, file transfers were getting slower and slower.
Why is an almost full NVMe SSD slowing down?
To be honest, the available space is more of a proposition
Almost all NVMe SSDs experience performance degradation as they reach their maximum capacity. When the drive is mostly empty, the controller has no trouble finding free blocks to write data to, but as it fills up, there are fewer free blocks and the controller has to rearrange the available data to make room, which slows down the drive.
However, this is where the differences in NVMe features and quality come into play. Many budget consumer-grade drives, like my Crucial P3 Plus, use QLC (quad-level cell) flash memory, which is much cheaper per gigabyte than high-end drives like TLC (three-level cell). Samsung SSD 9100 PRO.
- Storage capacity
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1TB, 2TB, 4TB, 8TB
- Hardware interface
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M.2 NVMe
The Samsung 9100 PRO NVMe SSD offers read speeds of up to 14.7GB/s and write speeds of up to 13.4GB/s, and it hits the mark. As the fastest SSD available in March 2025, the 9100 PRO is designed with professionals in mind. Designed to improve AI workflows, as well as speed up video and photo editing and exporting, this SSD is purpose-built to help increase your efficiency.
The main reason both QLC and TLC drives are faster when idle is because they are dynamic. treat the blanks as SLC (one-level cell) to use as a cache. It’s not the same as a true, fixed SLC cache (which is hidden from the user but helps performance) or even a hybrid setup, but it does significantly speed up maximum speeds nonetheless.
Now the difference between my cheap QLC and something like a higher end TLC drive is the raw performance of the memory itself. TLC is much faster than QLC, so even when full, TLC drives remain significantly faster.
Another important factor is special DRAMacts as a map of your information that the controller uses to quickly find what you need. This ultra-fast memory is designed to work directly with NVMe.
In contrast, it can use tricks like cheap DRAM-less drives HMB (Host Memory Buffer) to borrow a small portion of system RAM for the map. However, as NVMe fills up, the limited space can no longer hold the entire map, resulting in occasional performance hiccups.
A quick test showed that there was a problem with my full drive
It was a noble sacrifice, but it was worth it
Testing my NVMe speeds was pretty straightforward. I downloaded and installed it CrystalDiskMarkthen I configured the speed test for 5 passes to get consistent results and configured a 4GB test size to ensure the controller exhausts any potential caching tricks and writes directly to raw flash memory.
Before we start comparing each metric, it’s important to note that the benchmark numbers shown here don’t show a perfectly linear progression due to various factors. For example, the unusually low SEQ1M Q1T1 write speed in the 89% full test is likely due to the NVMe controller being busy with internal processes at that very moment (perhaps after the previous test ended).
Part of the change is the nature of the test itself—doing five passes instead of just one can present a bit. accumulation of temperaturethis is what I actually want to do to get a more realistic picture of performance under sustained workloads.
With that in mind, the most reliable parts of these results are the SEQ1M Q8T1 (maximum sequential throughput) results, which represent the drive’s peak theoretical throughput (numbers used in marketing materials), and the RND4K Q32T1 (random read/write using 4-kilobyte blocks of how 32 simultaneous disk requests are handled). cargo.
Here’s how an NVMe SSD performs at 95% occupancy.
This is 89% full performance.
This is what happened when I dropped the drive to 72%.
As the data shows, there is a clear correlation between more free space and faster speeds. While I expected a noticeable difference between the 95% and 89% results, I was surprised at how big the difference was between the 89% and 72% full results – the drive was able to pass the speed tests after freeing up a third of its capacity. It goes without saying that freeing up space also means faster loading screens and faster file transfers.
Stop treating space as space
Don’t feel bad if you’re thinking you’re spending money on an expensive NVMe SSD sitting half-empty. This is actually great for the driver’s performance and long-term health.
So don’t go overboard and delete everything but a single game. Keeping your drive around 20% free is a solid rule of thumb to help maintain good performance and longevity.
