I've been think about this for a while... In the past I've used old scsi cases to house sata drives and run the cable to an esata card. But I'm thinking of setting up 4 drives in a PC - the pc would only supply power.

Seems like a reasonable use of old crappy technology. I'll just need some molex>sata converters.

Anyone else doing this?

what will you be using the storage for? How important is speed?

I'm quite happy using an old PowerMac G4 as a file server over gigabit ethernet.

I'll probably buy one of these by the end of the year - [www.drobo.com]

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Grim Ninja did it using ATA drives

Check it out [ninjaproduction.com]

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<blush> I already have a gigabit server (733 powermac), but I want a lot of stuff to be local - and even faster.

grim's setup is interesting...

I was just gonna run the cables out the back of the PC and to the sata card, but setting up an interface for the sata cables on the PC is interesting - and a little neater...

I would advise reading up on SATA Port Multipliers.

Addonics is a good place to start looking for hardware.


Basically, you can get a 4 port eSATA card for $85 and a Port Multiplier for $90-ish.

You run 1 SATA cable from the SATA card to the PM and the PM acts like a hub to allow connection of up to 5 SATA hard drives. You can have up to 20 HDs running on a single SATA card. You need to have a card that supports PM. I haven't yet been able to figure out how the different chipsets interact, some specifications mention that the PM is compatible with specific SATA card chipsets, I don't know if it's exclusive to ONLY those though.

The eSATA/PM setup is great because you have less cable flow between boxes, you can still achieve 150 or 300 Mb/sec, you (potentially) save PCI slots, and you can attach up to 20 drives.

The eSATA/PM setup is not great because of the cost of the port multipliers (when considering a small installation), you're limited to channeling multiple drives through a single 150 or 300 Mb/sec line vs. multiple.

I have also seen PMs that can support multiple types of hardware RAID (1/0/JBOD mostly).

If I had the cash to redo my case, I'd go with an eSATA/PM setup.

I'm not gonna spend any money on this setup... but that sounds interesting..

let me get this straight... with a PM I can get the SAME transfer rates over one cable with, say, 4 drives as I could as I could with 4 drives and 4 cables?

hmmmmmm...

Not exactly...


Say you have a setup running at SATA I speeds. (150 MB/sec)
You have 4 HDs that transfer up to 75 MB/sec each.

Transfer to/from 1 HD with a PM would allow 75 MB/sec to pass.
2 HDs, 150 MB/sec
3 HDs, 150 MB/sec
4 HDs, 150 MB/sec

If you had 4 SATA cables instead, 4 HDs would result in 300 MB/sec transfer.


If you had a SATA II PM setup (300 MB/sec) then you'd be just fine. The idea is that you're rarely going to reach more than half the throughput of a single SATA line, so why not have multiple drives connected to it to save clutter?


So, it's pretty much like a hub. It allows one interface to share connections to multiple drives.

interesting - thanks