Unusually slow and unpredictable data transfer rates for SSDs in your system.
Unusually slow and unpredictable data transfer rates for SSDs in your system.
Problem as stated in title. This started several months ago but I brushed it off thinking it was only my internet, but I'm only just realizing that this issue is beyond just "weird PC thing that sometimes happens". Essentially, I've found for whatever reason that my three SSDs are massively under performing in terms of write speeds. This is something only my SSDs are dealing with. My HDD I use for storage seemingly does not struggle with this. It is not an internet issue; I have tried several speed tests through an ethernet cable and all of them readout consistent gigabit download/upload speeds in task manager with no spiking or bottoming out. My third SSD, a Samsung 860 QVO 1TB refuses to be recognized as anything but a 'Microsoft Storage Space Device', so Samsung Magician does not recognize it. Instead I have the performance graph of it trying to download from Steam as it appears in task manager. I'll also include a performance graph of the 980 on the right, as it demonstrates a similar issue. As seen the speeds are spiking and dropping rapidly. I have absolutely no clue as to what is causing this. For reference, I have tried these all to no avail: - Reviewing the Drive health (Samsung Magician and CrystalDiskInfo both reported all four drives in my computer in working order with no issues) - Ensuring AHCI mode is enabled (at least for the SATA SSDs) - Trying a different antivirus - Deleting any antivirus software - Turning off Windows Defender My only clue as to anything that could be responsible is that at start up this issue is not present. It appears about 30-60s after Windows initializes. I know this because I have a performance graph of the computer starting Steam and beginning a download for it to work perfectly fine until suddenly it doesn't. Steam also shows a sudden drop off of download speed from 100+ mb/s to hovering around 50mb/s (which I assume is due to the erratic write speed, as it only drops when the graph spikes appear). My specs are as follows: Windows 11 Pro, version 23H2 MSI Pro Z690-A DDR4 Intel Core i5 12600k 2x16GB Kingston Fury Beast @ 3600mhz Nvidia RTX 4070 Super Samsung 750 EVO 250GB SSD Seagate Barracuda 1TB HDD Samsung 860 QVO 1TB SSD Samsung 980 1 TB SSD Thermaltake 750W Gold Any advice or assistance would be greatly appreciated.
THE IMAGES SHOULD DISPLAY THE AVAILABLE SPACE RATHER THAN USED. Verify your chipset drivers are installed correctly, and check for any virtual drivers introduced by Microsoft Storage Spaces related to RAID or journaling. END EDIT Your storage devices are nearly full, leaving minimal free room for the pseudo-SLC write cache. The Samsung 980 supports up to 160 GB of write cache, while a 1 TB model can hold around 540 GB. This conversion from 3-bit TLC to 160 GB pseudo-SLC means each cell stores just one bit. Writing faster when it handles one bit per cell, but once the cache nears capacity, the drive switches to TLC storage. In your setup, you have about 897 GB used out of 931 GB total, leaving roughly 34 GB free. Based on this, the drive could theoretically shift half of that space into pseudo-SLC cache—about 17 GB of TLC to SLC. That translates to approximately 5.6 GB of write cache. As you approach full capacity, it will start writing to SSD using smaller chunks of SLC cache, reducing speed. At this point, it may move data from SLC to TLC to free space, resulting in slower speeds—around 800–1 GB/s initially, then dropping further as the cache fills. The Samsung 980 writes at ~82 MB/s per die in TLC mode, but even with multiple dies, achieving 3 GB/s in TLC is unrealistic. The 750 Evo uses MLC (2 bits per cell), offering faster speeds than TLC and SLC, though still limited. Its write rate is about 50 MB/s per die, which is sufficient for its design. The 8 dies and chips help, but write performance drops significantly once the cache nears full. For QLC drives, write speeds are even lower—typically 12 MB/s per die compared to 50 MB/s in MLC and 82 MB/s in TLC. Even with a larger capacity, the fixed small SLC cache limits overall throughput. Keep an eye on free space and consider managing usage to preserve performance.
It's often said that writing data like organizing books in a library works well when it's empty. If it's nearly full, locating a spot becomes slower, just like searching for a book in a crowded shelf. As the storage reaches 90%, finding space is tough; at 99% it's nearly impossible, and with 99.99% you're essentially searching through an entire library for one empty slot. Data is the information, shelves are the available space, and the closer you get to full capacity, the slower your drive becomes.
Thank you for your feedback. I understand your concerns better now. This problem seems to emerge shortly after Windows starts, unlike with my previous systems. On my Samsung 860, the Steam download began around one minute into boot, and spikes appeared about 40 seconds later. My 980 and 750 devices, which are older, also show similar issues even though they have different free space. Regarding your question about the "virtual" driver for Microsoft Storage Spaces—this term isn’t standard and I’m not sure how to locate or resolve it.
After additional testing, I noticed the download works fine on Wi-Fi but shows unusual spikes and drops when using a wired connection. This raises questions about a damaged Ethernet cable, problematic drivers, or performance issues with the SSD under higher speeds. Even if one of those factors applies, I’m puzzled by the timing—download speed suddenly halves after Windows starts. I plan to open Steam, monitor the download, and check for consistency over that minute before it drops sharply.
Through additional testing, I realized the problem wasn't the SSDs. I tried various other services, ran multiple benchmark tests on Samsung Magician, but couldn't replicate the issue from Steam. Steam was the only one causing this problem. I found a comprehensive guide online about Steam download issues and solutions, which suggested clearing the DNS cache and updating the computer's IP address. Following those steps resolved the issue I was facing. Now I can finally relax.