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bad write speed on non-system partitions and volumes in a file

Topics: Technical Issues
Dec 15, 2016 at 9:16 PM
my configuration:
1st disk: ssd ocz vertex3, system partition encrypted, aes. windows 10 64 bit pro, last updates, using uefi loader. read/write 300/200Mb/s (OK)
2nd: 3tb hdd, no enc, read-write 190/180Mb/s (OK)
3rd: 6tb hdd. aes, full disk (not a partition) enc, speed 180/25 Mb/s (write speed low)
4th: ssd ocz agility 3, now without encoding, speed 260/140Mb/s (OK).

tests I did:
  1. use 4th ssd for full disk enc aes, got 240/16 Mbs - write speed low (was thinking it is TRIM issue and slowdown because of it but its is not)
  2. create a volume in file on disk 4, mount and test it: 210/18
  3. create a volume in file (20Gb) on 2nd hdd, got 190/14Mb/s, , but the same device give 190/180 just after testing of a veracrypt volume (no reboots and no dismounting of volume from this disk)
I used VeraCrypt v1.19 and now I am using VeraCrypt 1.20-Beta-1. Same behaviour for both versions. My cpu is supporting aes acceleration and it is enabled. cpu loading is around 1-2% while a benchmark. All disks are connected to the same sata controller. ahci mode is used. No BlueScreens or messages in windows system logs happens. Just a low write speed. Give me know if You need any details.

Best Regards
Dec 17, 2016 at 12:18 PM
I did few more tests. Used MSYS2 dd tool to test speed. For testing I use 6tb whole disk encrypted hdd. Same system, same environment.
RAW read using dd of enc disk (dd if=/dev/sdc of=/e/1.dump bs=1M count=10000): 200 Mb/s
RAW write using dd to this disk (dd if=/e/1.dump of=/dev/sdc bs=1M count=10000): 180 Mb/s (yeah... understand the risks to write something to mounted disk, but for experiment it is ok)

And a situation when used mounted fs:
(added a ProcessExp screenshot, may be helps to trackdown an issue)
Feb 18 at 8:43 PM
Reinstalled windows because of another issues and... it is works as expected. Good write and read to container and to enc disk (#3 disk in my post). Yeah, changed a lot and I do not know what exactly was the issue. I think it was a iastor driver (intel management engine drivers). this driver is not installed in my current windows installation and was installed in the previous setup. Second idea is my system disk was enc but now it is not. Will give know if will face same issue again.
Best Regards