My parity drive is a Segate1.5tb, nice and fast. I know that the largest drive needs to be the parity drive.

 

My question is about if this WD 1.5tb is larger than the Segate by some stupid amount like a few kb. I'd hate to have to make it the parity drive. There is a sale so I want to pick up one more drive.

 

So maybe someone knows or has both of these.

 

Thanks.

They should have exactly the same number of sectors, well at least according to the online data, which you can get here:

 

http://www.wdc.com/en/products/products.asp?driveid=559

 

http://www.seagate.com/www/en-us/products/desktops/barracuda_hard_drives/barracuda_lp/

 

I have both the WD 1TB and Seagate 1TB drives and can confirm they are identical in size.

 

Regards,

 

Stephen

Thanks, it's just that I remember reading a post a while back where a user had this problem. Another drive of the "same" size was the smallest amount bigger and therefore would not work as a data drive. I just don't want a 5400rpm drive as a parity when the segate is screaming fast.

Thanks, it's just that I remember reading a post a while back where a user had this problem. Another drive of the "same" size was the smallest amount bigger and therefore would not work as a data drive. I just don't want a 5400rpm drive as a parity when the segate is screaming fast.

You are correct, if you have a choice, you want a 7200 RPM drive for the parity drive. 

 

When you do write to a 5400RPM data drive, performance will be slower than when you write to a 7200 RPM data drive, because the platter on the disk must rotate at least once between the "read" of existing contents, and the "write" of the new contents to the same sector just read.

 

If the parity drive is the slower rotating drive, it might be the bottleneck for writes to the faster rotating data drives.

Thanks, it's just that I remember reading a post a while back where a user had this problem. Another drive of the "same" size was the smallest amount bigger and therefore would not work as a data drive. I just don't want a 5400rpm drive as a parity when the segate is screaming fast.

 

Yeah, I have this HPA problem, and it was too much of a pain to try to fix it, so I'm just living with it for the time being.  I'm going to make sure that the next drive I buy is significantly larger (maybe a 1.5 TB) to avoid this problem in the future.