My Sandisk became super slow but fixed by reformatting

[sakenotabibito]

The problem is fixed now, but I just wanted to try and find out what the problem was in case it happens again. Basically, I connected my Sandisk Portable SSD 1TB last night after not using it for a few months but when I tried to moves files to it, it was super slow. I tried to check the speed on Crystal Mark, but it just stalled forever not producing results. I checked using command prompt and it told me that the drive had a write and read speed of around 1mb/s. I tried reversing the cable (I was only using the supplied official cable) but to no avail. Tried formatting the drive, but Windows Quick Fomat would just get stuck. In the end, I did a full disk format. The format actually failed, but after, I could successfully run a quick format and the speeds returned to what they should be: around 500-800mb/s. However, I am still left with the huge question of what on earth happened. Is this normal? What causes the issue and how do I fix it in future? Is formatting the only option? Have to say, not impressed with Sandisk drives.

[SBrown]

@sakenotabibito Could be TRIM and garbage collection.
The SanDisk Portable SSD has TRIM enabled by default, but the drive ships with exFAT. TRIM is also enabled by Windows 10 and 11 by default. So if you are using NFTS on the drive, make sure TRIM is not off (1) Enabled in Windows.

C:\WINDOWS\system32>fsutil behavior query disabledeletenotify

NTFS DisableDeleteNotify = 0 (Disabled) means that TRIM is ON
NTFS DisableDeleteNotify = 1 (Enabled) means that TRIM is OFF

[sakenotabibito]

Thank you for the reply. It is not disabled: displays as 0 when I checked on Command Prompt.

[johnjacobb40]

@sakenotabibito

The problem is fixed now, but I just wanted to try and find out what the problem was in case it happens again. Basically, I connected my Sandisk Portable SSD 1TB last night after not using it for a few months but when I tried to moves files to it, it was super slow. I tried to check the speed on Crystal Mark, but it just stalled forever not producing results. I checked using command prompt and it told me that the drive had a write and read speed of around 1mb/s. I tried reversing the cable (I was only using the supplied official cable) but to no avail. Tried formatting the drive, but Windows Quick Fomat would just get stuck. In the end, I did a full disk format. The format actually failed, but after, I could successfully run a quick format and the speeds returned to what they should be: around 500-800mb/s. However, I am still left with the huge question of what on earth happened. Is this normal? What causes the issue and how do I fix it in future? Is formatting the only option? Have to say, not impressed with Sandisk drives.

Your SanDisk SSD was likely slow due to file system errors or bad sectors from not being used for a while. That’s why quick format and speed tests didn’t work. The full format helped fix those issues, which is why the drive works normally now. This can happen if the drive wasn’t ejected properly before or sat unused too long. If it happens again, try running chkdsk or a full format. If it keeps happening, the drive may be failing and should be replaced.