Sandisk Extreme 64GB - Slower write speeds after system format

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@zakear wrote:

@moogle

 

>>Using SecureErase in PartedMagic has restored it back to normal

 

when you said “it is back to normal” by using SE/PM, I’d like to ask you 2 questions on top of this:

  1. are you confirming the read/write speeds are back to the from factory speeds (up to 190 writting/up to 245 reading)?
  2. if yes #1,  what format have you choosen for to get them back (e.g. fat32, extfat, other)?

Thanks, 

Hi zakear,

  1. Yes, I used CrystalDiskMark to test read and write speeds on two different 64GB drives. One was formatted to NTFS and the other was left as exFAT like when it came from the factory. The speeds were roughly about 32-34 MB/s read and 12-15 MB/s write on the sequential parts of the benchmark. Both drives were performing similarly poor after having been used for a year and filled up many times.

  2. After the SecureErase (I booted to linux and used hdparm instead of the gui tool as I couldn’t see my flash drive. See this page https://blog.oxplot.com/make-usb-flash-write-fast-again/ on what commands to use.) the drive no longer has a filesystem so I formatted it back to NTFS 4K cluster size using Windows 10.

I went and performed the CrystalDisk benchmark and speeds were back up to around 211 MB/s read and 139 MB/s write which seemed back to normal speeds.

I also tried copying a large file to the drive before and after secureerase in Windows 10 and before I was getting around 3-5MB/s write speeds, afterwards the drive was copying at around 95MB/s for about 10 mins (the time it took the transfer to complete) which seemed about right as I was copying from HDD -> Sandisk drive.

The drive was hot afterwards but back and performing normally. All these posts about ruining the factory partition/sector size is just rubbish. The drive uses SSD flash chips but I don’t think there is a controller embedded inside to automatically perform TRIM commands or do wear levelling, which is why the drive will slow down over time with use.

Maybe a majority of users who rarely use the drive to copy large files won’t see an issue, but if you use the drive too much it will slow down significantly.

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