Backup Storage Performance | NAS or Onboard SATA?

I run two SSD RAID 10 arrays each with a hardware RAID controller. I want to have a dedicated HDD that stores the incremental backup files and disk images for each array (using Acronis software).

I'm wondering which structure I should use viz. performance:

1) I can attach the (2) backup-HDDs to SATA on the motherboard, and let the software copy the backups that way.

OR

2) I an attach an NAS with the drives in there, and have the software write the backups via ethernet.


While I suppose the latter method physically separates the two media (good for localized physical trauma to the actual computer), I'm wondering what kind of latency I would be introducing since it's 1) SATA vs 2) ethernet+NAS controller board.

At the same time, so long as there isn't additional processing going on on the motherboard (which I assume is equivalent in both cases), should I care about the latency anyway? At worst... the data gets written a few minutes later as backups, but of no real relevance?

Thanks in advance to posters.

I use Acronis True Image(2009) also. A NAS can be a little slower, but I prefer to keep my backups on external drives. I have my backups scheduled for 2:00am, so it doesn't really matter how fast or slow the backup is as long as it gets done. My backup is done long before I wake up, so speed isn't an issue.

The benefits of a NAS or external drive is that it can also be used with more than one computer. If you are interested purely in speed, then attach the drives directly to the motherboard.