Slow writes to SSD

[Keith W]

So here's the story: I have a 500GB 970 Evo Plus NVMe, about 40% full on the motherboard as a C:\ system drive. Works as quick as the board/CPU/RAM (ASUS 970 gaming aura, FX8350, 16GB) will let it. It's only PCIe 2. It's still quite quick. 1.4GB/s read, 1.1 write (seq) from Crystal Mark

Also have a Cruicial CT240BX500SSD1 SATA ssd, about 60% full of crap plus an old bootable OS on it, as E:\ drive on SATA (3) port 1.

All BIOS stuff is, hopefully set up ok. Running win10 1909.

Problem: When I write to the Crucial ssd, E, from the Samsung NVMe, C, the write rate starts off stonking (1GB/s) rapidly falling off after about 3GB to about 400MB/s for a while. If I try this exercise with a 16GB file after a clean boot the 400GB/s phase lasts to the end. Quick enough. If I've run anything which has left its trail of debris in my RAM it will drop off to as low as 6MB/s at times towards the last l GB or so. Too slow. Paging ???

I have a load of magnetic SATA drives for general crap and the speed from/to all of them is as expected i.e. 120 - 150MB/s

If I do a big one (37GB, C:\ > E:\ ) I get the same picture as above but the slow phase kicks in earlier and persists to the end. On one test, average transfer rate is just 68MB/s. Worse than between the magnetics or mag to ssd.

Why ?

 

[ChatGPT]

The drop in write speed you are experiencing when transferring files from the Samsung NVMe SSD (C to the Crucial SATA SSD (E could be influenced by various factors. Here are some potential reasons and solutions to consider: 1. Write Speed Degradation Over Time: As SSDs fill up, especially with cached data and older OS installations, performance can degrade. This is due to the way SSDs write data and wear-leveling algorithms. Try freeing up some space on the Crucial SSD or consider a secure erase to reset it to its original state. 2. Background Processes: If the system is occupied with background tasks that use the disk heavily, it could impact the transfer speeds. Ensure that no resource-intensive tasks are ongoing while transferring files. Monitor system resource usage during file transfers to identify any spikes that might be causing the slowdown. 3. Device Aging: The Crucial SSD might be experiencing performance degradation or firmware issues, especially if it's an older drive. Try updating the SSD firmware if available, or consider replacing it if it's significantly outdated. 4. Driver/BIOS Updates: Make sure you have the latest SATA controller drivers and BIOS updates for your motherboard. This can sometimes resolve compatibility issues or performance limitations that may affect disk transfers. 5. Check SATA Ports: Verify that the Crucial SSD is connected to a SATA port that supports the highest speed on the motherboard (e.g., SATA III 6Gbps). Plugging it into an older port could limit its performance. 6. NVMe to SATA Transition: Transferring data from an NVMe drive to a SATA SSD can encounter bottlenecks due to the inherent performance differences between these interfaces. Write speeds can be slower when transferring between different types of storage. 7. Paging/Cache: Monitor system memory usage and check for any excessive paging during file transfers. High memory usage can lead to increased paging, impacting overall system performance and file transfer speeds. By evaluating and addressing these factors, you can potentially improve the file transfer speeds between your NVMe and SATA SSDs. If the issue persists, consider further diagnostics or hardware replacements to optimize data transfer performance.