I'm preclearing my first set of drives, and one of them has made it to copying zeros to the drive, but the transfer rate is extremely slow (~15 MB/s). This drive has been in service for several years, and I moved a few TB of data onto and off of this drive this week and it did not report any errors before preclearing.

 

I'm guessing this is not normal since my other drives have transfer rates >80 MB/s. The other drives are a Hitachi (2TB), and two other Western Digital drives (1TB each). The drive that is moving so slowly is a Samsung F2, 1.5TB drive.

 

As a last bit of information. It appears that the system is reporting this drive as an IDE drive as its ID is hda. Could this be the reason for the slow write speeds? I've been looking through the MB manual, but I haven't found a setting for ACHI yet. I was planning to wait on the drives to finish preclearing before I took another look.

 

Should I be expecting higher write speeds for a preclear? I followed the wiki verbatim, but is it possible I did something wrong? Does it sound like the drive configuration is the problem?

 

Any suggestions are appreciated! Thanks, again!

 

yes, it is slow

yes, it could be because you've set the bios to emulated IDE mode  (emulated mode is often slower)

yes, it could be just that you have not set the bios for best performance. (ACHI mode)

or

it could be having errors, and is constantly being reset,  but since you did not attach a syslog, nobody can look for errors in it.

I thought I would need to wait for it to finish for a syslog to be generated. Is that correct?

 

The Hitachi drive is nearing completion, so I was planning to wait on it before canceling the Samsung drive and trying to find the correct settings in the BIOS. I'm not sure what I'm looking for ATM, because there doesn't appear to be anything labeled ACHI or legacy (at least in the MB manual). Hopefully I'll find what I'm looking for just by poking around. I need to preclear the Hitachi drive 2 more times as it's the only new drive that I have. So that will give me another opportunity to run the Samsung disk after correcting the BIOS (hopefully).

I thought I would need to wait for it to finish for a syslog to be generated. Is that correct?

no.  You can get a copy of the syslog at any time.

The Hitachi drive is nearing completion, so I was planning to wait on it before canceling the Samsung drive and trying to find the correct settings in the BIOS. I'm not sure what I'm looking for ATM, because there doesn't appear to be anything labeled ACHI or legacy (at least in the MB manual). Hopefully I'll find what I'm looking for just by poking around. I need to preclear the Hitachi drive 2 more times as it's the only new drive that I have. So that will give me another opportunity to run the Samsung disk after correcting the BIOS (hopefully).

You don't need to run the disk through another pre-clear unless you want to.  Look for IDE Emulation or Legacy mode options.  (turn them off)

Thanks for the help, yet again!

 

I found the AHCI setting in one of the submenus. I spent more time dragging out my behemoth of a 15" monitor than I did fiddling with the BIOS. So far it looks like the read speeds are much improved now (>100 MB/s). So hopefully that was the issue. If it slows down again I'll post a syslog and try again.