The drives that Philip mentions are expensive, but I understand that for a RAID setup, a person should use these "enterprise" drives. So I'll get them.
The RE3 1TB (
WD1002FBYS) unit is an easier pill to swallow (even though you need more, you end up in the "sweet spot" in terms of capacity, performance and cost; performance is dependent on parallelism, not capacity = the more members, the faster you go, and they also increase capacity at the same time, and happen to be cheaper capacity wise than the 2TB RE4).
A few questions now please. Which Sans Digital enclosure should I get?
Honestly, they all look quite a bit the same: TowerRAID TowerRAID Plus (NEW), and TowerSTOR. I don't need a huge one, because, frankly, I don't want things to get any more confusing than they already are.
For a RAID card, you'll need a unit with an
SFF-8088 port per 4x disks (aka External MiniSAS cable that plugs into the port on the enclosure; take a look at the blown up pic to see what the female end looks like).
4 Bay unit (
TR4X)
8 Bay unit (
TR8X)
The basic models you've seen are variations (ports can differ, and some are kits). BTW, the Sans Digital enclosures come with the external cables you need to attach to the card, so you won't have to buy those too (more common that you do).
If I end up putting six or whatever number of these drives, not RAIDED, inside my Mac Pro (how many do actually fit inside, by the way, without having to get special hardware?; size-wise, I'd want to be able to use whatever size these Black Caviars are, because I have a number of them... so I guess that means a maximum number of six drives*), and then keep my other Caviars (for backup) in my FirmTek unit, then maybe I could use the enterprise drives in the Sans Digital enclosure just for the one or two current projects that are most important.
4x in the HDD bays, and 2x in the optical bays = 6x total 3.5" disks (you'd have to pull the OEM optical disk out).
There may be a way to get more in, if you use some 3rd party or DIY'd adapters, but you'd also need additional ports to connect them (only 6x SATA ports on the ICH = system's built-in SATA, USB, and Ethernet ports).
Physically speaking, you can get more in using 2.5" models (4x in each optical bay). 2x of those, + 1x DX4, and 4x HDD bays, you can stuff 16x of these inside.
I doubt if I need more than 4GB (ah, but I just remembered that in RAID, you need double the space, right?).
It depends on the level.
RAID 0 =
n members * capacity of a single disk (based off of the smallest capacity member if they're not the same)
RAID 1 = same as a single disk
RAID 10 =
n/2 * capacity of a single disk
RAID 5 = (
n - 1) * capacity of a single disk
RAID 6 = (
n - 2) * capacity of a single disk
Then on the subject of connecting the Sans Digital enclosure to my Mac Pro... should I get a card from Sans Digital or get a card from ATTO or Areca?
Get a separate card. Going externally, I'd go for the
ARC-1880X (6.0Gb/s compliant, and definitely capable of handling SSD's for later on). There are other cards, but it will depend on what you need, as they may not be much cheaper (i.e. less value than what this model has to offer).
More specifics would help (number of disks that will be attached).
And on the subject of the card that goes into my Mac Pro... would any of the above-recommended cards allow me attach not just the Sans Digital enclosure, but also my FirmTek unit?
The Areca
*might*, but I've never tried it myself. Usually you use either 1x port per disk (i.e. your current enclosure would need 5x eSATA ports on the back) , or use SAS Expanders (SAS version of a PM chip/enclosure; some are separate units, others included in the enclosure) to run more than 1x disk per port.
But as I've not tested what you're asking, I'm not sure if the SAS chip will also recognize a standard PM chip (what's in your enclosure). Even if it did, you'd have a problem with your drives as they are anyway.
If they're not all that new, you can get a copy of the WD TLER utility and adjust thier timings, but you may also lose the data on them (not sure what you've set up, but here's a
How-To and a way to get the utility).
P.S. *I have an external Blu-ray burner, by the way. I don't know if that negates the need for the internal optical drive or not.
It might. How do you connect it to the system?
