Getting SAS'y with a MacPro3,1 : OCTO-boot

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phunguss

Active Tinkerer
Dec 24, 2023
354
308
63
Stillwater, MN
I have two classic MacPro3,1s... and I have some old SAS drives laying around. I thought it would be a fun experiment to try to get a SAS controller put in to use the drives. Non-Apple of course, because of the horrible reviews on it. I found an Areca ARC-1222 on eBay, and got it delivered for US$21.

Part 1, Physical Installation

Since the Apple card is full length, removing the SFF-8087 cable from the motherboard and planting it on the card is easy. But the ARC-1222 is a half-length card, so we have to see if we can adjust the cables. Remove all drives and the front fan. Remove the SFF-8087 from the motherboard, remove the 8 screws holding down the SAS connectors, and pull out the cable (careful of the wifi/BT/other thin wires in there).
mp31-stripSAS.jpg

mp31-originalSAS.jpg

Starting on the left, you have power (the SFF-8087 pointing downward) and the drive bay SAS connectors 1 through 4. I need the SFF-8087 to be between connector 2 and 3. We are going to do some bending instead of soldering! No cable-stretcher required! With a little manipulation, you can untangle the wires between connector 1 and 2, the power, and the SFF-8087. Physically swap the positions of connector 1 and 2. There is just enough slack to get the SFF-8087 between 2 and 3, and still have the power reach the motherboard.
mp31-destinationSAS.jpg

Screw the 4 SAS ports back onto the shelf mounts in order from left to right: 2,1,3,4. Now the SFF-8087 is just long enough to clip into the ARC-1222 in the top PCIE slot. Not long enough to go lower.
mp31-installedSAS.jpg

And when you install a full size 3.5 drive, the fan will have hardly any clearance. Luckily I had a WD-Ice 2.5 to 3.5 converter, so I could put a 2.5 Drive in the 4th bay where the fan is.
mp31-wdice.jpg


Part 2, Spare drives

Since we now have zero of 4 drive bays to boot from, we have to use the optional SATA ports on the motherboard underneath the front fan. I used a thin strap of aluminum to mount two 2.5 drives underneath the existing DVD-ROM drive (I forgot to take a photo of the completed install).
mp31-dualdrive.jpg

Route the two sata cables from the motherboard to the top drive bay under the tray.
mp31-dualSATA.jpg

I installed a Molex 4pin to dual SATA power cable to power the two 2.5 drives.

Part 3, Software

This was a bit tricky. There is windows software to configure the card, but not MacOS software. So I installed the card in a windows environment so I could find the MAC address.
mp31-arc1222.jpg

Once I had that, the card went back into the cMP3,1. The ARC-1222 has a built in ethernet port for in-band management. Connecting the Areca to the network, then I was able to log into the card from the cMP3,1. I have 3x2TB and 1x4TB drives, so not ideal for a raid setup. But I tried it, and initializing a 4x2TB drive as RAID-5 was taking some time. Google leads me to beleive that it would take between 24-48 hours, so I abandoned that just so I could verify MacOS could see the drives. I converted the raid to individual 'pass-through' disks. Upon restart, nothing showed up. Downloaded Areca driver for BigSur and installed in Ventura. Restarted and still no drives. Finally rebooted in Snow Leopard installer and the drives showed up, but failed on formatting. Restarted in Ventura again and then they formatted just fine.

mp31-hexboot.jpg

OCLP of course! I have Ventura and Sonoma on the SSD, with room for Sequoia. I have Snow Leopard, Lion, High Sierra, Mojave, and Catalina on the Mechanical drive. No idea what I really need the SAS drives for yet, this was just a proof of concept. More testing later...

I also swapped out the wifi a/b/g card for a newer a/b/g/n that I had laying around. Total drives: 4 SAS mechanical drives, the original IDE/PATA DVD, 500GB SSD, and 750GB Mechanical drive.
 
Last edited:

phunguss

Active Tinkerer
Dec 24, 2023
354
308
63
Stillwater, MN
Marchintosh 2025

I pulled out the my second cMP3.1 and removed the optical media drive. This will be a cage for 14 2.5" drives. I already have an Areca ARC-1680 IXL 16 with 3 internal SFF-8087 connectors and 1 external for raid expansion. This cMP3.1 has a Bluetooth in it but no wifi, so I will be adding that. This machine was a $5 project from Free Geek Minneapolis.
cmp31-01-ready.jpg


The Areca card came with a low profile bracket and not the regular tall bracket.
1680-fp1.jpg

A little bending, drilling, and Pop-Rivets.
1680-fp2.jpg

But I got something wrong, as the card is fully inserted but the bracket extends too far. I will adjust that later.
1680-fp3.jpg

Closer shot of the existing area we will be upgrading.
cmp31-02-ready2.jpg

Remove the SFF-8087 from the motherboard, remove the power connector for the internal bays, and remove SAS drive connector 1 and 2. Install the Wifi Card. Remove the PATA cable and molex power from the optical bay, unplug from the motherboard, and separate the cables.
cmp31-03-removal.jpg

Install the wifi antenna cables. install two longer SATA cables on the motherboard to go up to the optical drive bays.
cmp31-04-mobosata.jpg

Untangle the internal drive bay cables so the SFF-8087 can reach the card, swapping positions of 1 and 2. Reinstall so the actual cables are in order 2-1-3-4. I have also attached 1 more quad pigtail SFF-8087 to SAS connectors and routed it up to the optical bay. Reinstall the molex power from the motherboard to the optical drive bay.
cmp31-05-install.jpg

The optical bay so far...
cmp31-06-bay.jpg


Building some drive cages. I designed one tray to hold 8 thicker 2.5 SAS drives.
8bay-layout.jpg

Some drilling, and sheet metal origami and I have a bay.
8bay-folded.jpg

Then I designed a bay for 6 thinner 2.5 drives.
6bay-layout.jpg

And some more metal origami. It is ugly, but it is internal.
6bay-folded.jpg

The web interface to the new card.
Screen Shot 2025-03-22 at 9.32.17 PM.jpg


Up next...

Adding two more quad pigtails to the optical bay. Installing all the drives and power. I will utilize one of the spare motherboard power outlets designated for GPU power to route up to the optical bay as well.