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External eSATA port multiplier for non-multiplier-compliant SATA port

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March 3, 2012 5:23:39 PM

I'm trying to connect multiple external drives to a 2011 Mac Mini by feeding a SATA cable outside the case. The problem I'm having is that the motherboard SATA port does not support Port Multiplying. I'm trying to find an external (or integrated into a 4+ bay enclosure) hardware Port Multiplier that will be transparent to the OS and just work with my existing mismatched drives in JBOD.

I thought I'd found one that claimed to work with any ACHI compliant SATA port but now I can't locate it. Does anyone know of a product that will solve my problem. I thought the one that would work was an Addonics but I can't find it.
March 3, 2012 5:30:41 PM

I found the article I was referring to:
http://www.tomshardware.com/reviews/storage-accessories...

Here is a quote from it:

"The real issue is port multiplier compatibility, which AHCI supports. It is first necessary to make sure AHCI is enabled in your motherboard or controller BIOS, because most controllers still support legacy modes. Once we set the JMicron controller to AHCI, we could get started with the Addonics eSATA Port Multiplier.
The device works as simple as the product name sounds: It utilizes one physical Serial ATA connection to run as many as five drives through it. The operation is entirely transparent to the operating system."

However, on the specs page for this product is says:
"* External eSATA Port Multiplier requires connection to a PM(Port Multiplier) compatible eSATA controller."

So I guess the original article was a little incomplete...

Still looking for a solution to this. Thanks.
a c 277 G Storage
March 3, 2012 8:14:21 PM

Our member firewire2 has an interesting solution in his 40 tb home server. He found a device that will RAID up to five SATA drives, and present the result as a single SATA device. Check out his build at http://www.mpcclub.com/forum/showthread.php?t=22898&pag...

Let me know if that would address your issue.

EDIT: Here is an example of the device that he used: http://www.amazon.com/gp/offer-listing/B004JPUZWU/ref=d...
-----------------------------------

Random rant: DO NOT run SATA outside the case. There is a reason eSATA was invented. It's because SATA is not designed to go outside the case.

Do not use a physical converter that creates a back-panel eSATA connection from an SATA controller port. SATA and eSATA voltage levels are different. They overlap, so sometimes it works, but it's a gamble I would never take.

Most members disagree with me.
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March 3, 2012 8:51:27 PM

Hey, thanks for the great lead! That device looks pretty interesting. In the specs, it says as long as the host supports the "eSATA" standard, it "Supports PM aware and non-PM aware host". Most of the others I've looked at indicate that they need a SIL3124 or SIL3132 chip set to function as a pure port multiplier.

Now to find out if the Mini's SATA port is compliant enough to cooperate with this card. I know the cables can be adapted, the question is whether there are any communication issues. Another quote from the specs:

"Supports SATA 3Gb/s Gen2i and Gen2m (External SATA Connection, eSATA)"

Anyone care to comment how this relates to a standard Apple motherboard SATA connection?

Best solution

a b G Storage
March 5, 2012 9:14:07 PM
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WyomingKnot - Thank you for mention my solution!...

hoffsta - the SPM394 and SMP393 that I used is a PM bridge with I/O processor to control the RAID, so its RAID independent from ANY OS. As long as the OS supports the connected SATA port, then you can access the RAID.

Since these devices are PM (JBOD)/RAID modes. To use correctly, follow the below rule then you're OK.

PM (JBOD) - requires PM SATA/eSATA host

RAID - SINGLE RAID - as far as SATA/eSATA host concern it sees a SINGLE HDD and the RAID is transparent to the OS. the raid function is controller by SPM393/SPM394.

Use the Hot spare function if you need a high reliable raid -

RAID - Multiple RAID sets 0 such as:
1_ a RAID1 (2x drives) and RAID5 (3x drives) or
2_ TWO RAID1 and 1x hot spare

To see BOTH raids, the host must support Port Multiplier because there are MORE than one drive needs to access.

AS far as MAC Mini, there is TWO solutions for you:

FireWire port
You can use this http://www.datoptic.com/sata-to-usb-firewire-bridge-sup...
and SPM393, then you can either use 5x connected HDD as JBOD or RAID via FireWire port. the draw-back with this is trnasfer rate is about 80MB/s

eSATA port via SATA adapter:
You can use either SPM394/SPM393 and configure as a SINGLE RAID. It should work with transfer rate up to 250MB/sec
March 5, 2012 9:30:28 PM

Firewire, Thanks for jumping in here with the expert info. I now feel pretty confident that I know what all my options are!
March 5, 2012 9:30:42 PM

Best answer selected by hoffsta.
!