Mac Pro Support Port Multiplier?

Question

Level 1

88 points

Mac Pro Support Port Multiplier?

Hi
I just found out a few minutes ago that my Mac Pro is hiding an extra pair of SATA ports. This is great because I was going to buy a 2 port ESATA card and now I don't have to. But there is one more issue. I plan on hooking up 10 sata drives, via two ports, using two SATA port multipliers. Does the two secret SATA ports support multipliers? I read that PM support has to be specifically enabled on the ports for the PMs to work. Anyone know?

Mac Pro 2.66 / 2GB / 640GB & MacBook 1.83 / 2GB / 160GB, Mac OS X (10.5.1)

Posted on Dec 18, 2007 8:47 PM

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Answer 1

The hatter

Level 9

60,990 points

Dec 19, 2007 3:09 AM in response to l008com

2-port cards don't support RAID and are only 1x.
The two "ODD" ports are bootable and support RAID but not PM.

Best bet is something like $250 Sonnet Tempo 4-port PM and a set of 500P.

+PS: funnily that there are half a dozen messages or questions about Sonnet 500P etc in the last two days.+

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Answer 2

l008com Author

Level 1

88 points

Dec 19, 2007 6:55 AM in response to The hatter

I don't need raid and I don't need 4 ports and I don't know if i even need 3Gbps, but the card you suggest bumps my project from $450 to $700. Are the "ODD" ports you refer to the hidden ones? That stinks. This plan of mine to build a cheap yet reliable optical tower just isn't going to happen. I have one made of USB2 now and it was cheap but its very unreliable.

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Answer 3

mbean

Level 4

1,250 points

Dec 19, 2007 10:25 AM in response to l008com

The two SATA mother board connectors do not support SATA PM. I have tried connecting a 5-bay SATA PM enclosure to them and only the first hard drive is mounted.

Using a SATA host adapter is a much better option than trying to use the "ODD" SATA ports as it provides hot swap. However, there is another solution. DAT Optic sells the Sbox-R which uses the Silicon Image SiI-4726 chip to configure a 5-drive RAID that appears as one drive to the Mac Pro motherboard SATA ports.
http://www.amug.org/amug-web/html/amug/reviews/articles/datoptic/sboxr/

The downside is that the hardware RAID is slower than using Disk Utility to create the RAID with a host adapter. In addition, the hardware RAID has to be created by a Mac Pro with a SATA PM host adapter and then moved to a Mac Pro using the motherboard SATA ports. The RAID cannot be created without a SATA PM host adapter. This can be a catch 22 for some users 😉

Have fun!

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Answer 4

l008com Author

Level 1

88 points

Dec 19, 2007 11:22 AM in response to mbean

I'm not building a raid, i'm building an optical drive tower. I don't need raid and I could easily go without hotswap too. I just need PM and cheapness.

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Answer 5

The hatter

Level 9

60,990 points

Dec 19, 2007 11:56 AM in response to l008com

Why do you think there is a Port Multiplier for optical devices?

Every PM controller and enclosure is built for storage devices.

I guess there could be an Infiband or mini-SAS (which run $75 for the cable alone).

Or Firewire. USB2 has never ever been half-way respectable or usable for DVD burners - no Mac I know of, and most that tried to use USB2 gave up trying.

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Answer 6

l008com Author

Level 1

88 points

Dec 19, 2007 2:36 PM in response to The hatter

Since when are port multipliers device specific?
You're telling me this thing will only work with hard drives and not optical drives?
http://www.addonics.com/products/host_controller/ad5sapm-e.asp

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Answer 7

mbean

Level 4

1,250 points

Dec 19, 2007 4:26 PM in response to l008com

You're telling me this thing will only work with hard drives and not optical drives?

http://www.addonics.com/products/host_controller/ad5sapm-e.asp

If you have a Silicon Image based SATA PM host adapter the Addonics 5X1 eSATA Port Multiplier may work with an optical drive on a Mac or it may not. I have found that combination is not as reliable as a FireWire connection for Macintosh computers.

In any case, the Addonics 5X1 eSATA Port Multiplier will NOT work with the Mac Pro mother board ports.

Have fun!

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Answer 8

l008com Author

Level 1

88 points

Dec 19, 2007 4:39 PM in response to mbean

Well reliability is the whole reason I'm trying to upgrade away from USB2 in the first place. SoooOOOOoo you're saying FireWire to IDE bridge boards are more reliable than esata?

If thats the case, know where I can get ummmmmm 10 cheap firewire 800 bridgeboards? No RAID or anything needed, just 10 optical drives connected to 10 firewire bridge boards, all chained together. Though even firewire 400 wouldn't be so bad. Theoretically if all 10 drives were reading from the fast part of the disk, it would be a bottleneck, but with the laws of probability an all, i'd be looking at an average speed of around 35MBytes/sec reading from 10 CD drives at 52X each.

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Answer 9

mbean

Level 4

1,250 points

Dec 19, 2007 5:59 PM in response to l008com

SoooOOOOoo you're saying FireWire to IDE bridge boards are more reliable than esata?

What I am saying is that SATA Mac drivers are usually not designed to support all of the commands used by optical devices. This can cause problems with some SATA optical interfaces.

If you were looking for a fast and reliable interface for hard drives eSATA is the way to go. If you were using the optical devices on a PC, I suspect that eSATA would be the interface of choice.

However, my experience tells me that optical devices require drivers that fully support the ATAPI command set and I have found that is no always the case with SATA Mac drivers.

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