unRaid is Raid 4. The big (current) user of raid 4 is NetApp, however they use their own file system (WAFL) plus NVRAM/ cache to make it all work well. unRaid is the cheap version of raid 4 that doesn't have the fancy tricks to help performance.
I would suggest Wikipedia on the subject since the raid article there is really good. Basically Raid 4 uses one drive as parity, while raid 5/6 distribute the parity across multiple disks. So Raid 4, not being striped, gets limited to a file on a disk meaning if you use green drives, for example, you won't get the throughput to saturate even one disk.
If you are going to be using that many drives, use a norco 4020 or 4220. The cost of those 5-in-3's basically makes the Norco case cheap once you hit 10-15 drives.
As for raid controllers, I've been using the Adaptec 31605 for a long time. In my new WHS I was going to use two but I think I'm going to switch to either the Areca 1680LP (1 internal 1 external port) or the Adaptec 5805 + HP SAS Expanders. The big driver for me is the need to use a second 4U to hold the drives. I'm probably going to sell only one of the 31605's and keep the other just because they, for whatever reason, seem to work with every drive without issue.
And as for gigabyte boards, my old WHS used a UD3P, and my main system uses a X58-Extreme. The UD3P has been working fine for a long time, an the X58 Extreme for a while when I was running SAS held an Adaptec 5805, 31605 and 3085 all at the same time.
If you end up needing help I'm only a town or two south of PA.
I would suggest Wikipedia on the subject since the raid article there is really good. Basically Raid 4 uses one drive as parity, while raid 5/6 distribute the parity across multiple disks. So Raid 4, not being striped, gets limited to a file on a disk meaning if you use green drives, for example, you won't get the throughput to saturate even one disk.
If you are going to be using that many drives, use a norco 4020 or 4220. The cost of those 5-in-3's basically makes the Norco case cheap once you hit 10-15 drives.
As for raid controllers, I've been using the Adaptec 31605 for a long time. In my new WHS I was going to use two but I think I'm going to switch to either the Areca 1680LP (1 internal 1 external port) or the Adaptec 5805 + HP SAS Expanders. The big driver for me is the need to use a second 4U to hold the drives. I'm probably going to sell only one of the 31605's and keep the other just because they, for whatever reason, seem to work with every drive without issue.
And as for gigabyte boards, my old WHS used a UD3P, and my main system uses a X58-Extreme. The UD3P has been working fine for a long time, an the X58 Extreme for a while when I was running SAS held an Adaptec 5805, 31605 and 3085 all at the same time.
If you end up needing help I'm only a town or two south of PA.
