Mac Pro 6,1 used in a Target mode configuration

[bxs]

The MP6,1 has 6 TB-2 ports.

If one has 5 other Macs with TB ports can each one be connected to the MP6,1 at same time and have the MP6,1 viewed by each in Target mode ?

I asked AppleCare about this and I was told it's a configuration that Apple supports. This surprised me as I thought only a single 'target mode' connection is supported.

Has anyone tried this ?

 

[mikeboss]

I would strongly advise against this. there's no filesharing mechanism running on the nMP, so concurrent access to the same file(s) would lead to unpredictable behavior.

 

[bxs]

I would strongly advise against this. there's no filesharing mechanism running on the nMP, so concurrent access to the same file(s) would lead to unpredictable behavior.

Yes, I am aware of the 'concurrent' issue, but that really is of no concern for me as media on the server MP6,1 is only read by clients who then produce outputs that get stored back to the server. Each of my clients work in this manner so writing concurrently to same file never happens.

My question is still.... can multiple clients use target mode using TB to a single MP6,1 without other issues besides 'concurrent' ones ?

 

[goMac]

...Why not install OS X Server and run the Mac Pro as an actual file server? Or buy a NAS?

The reasoning for doing this is entirely confusing. If you want Thunderbolt speeds, just use the Mac Pro as an actual server an do IP over Thunderbolt. OS X Server can serve to clients over Thunderbolt.

http://support.apple.com/kb/PH17001?viewlocale=en_US&locale=en_US

 

[bxs]

...Why not install OS X Server and run the Mac Pro as an actual file server? Or buy a NAS?

The reasoning for doing this is entirely confusing. If you want Thunderbolt speeds, just use the Mac Pro as an actual server an do IP over Thunderbolt. OS X Server can serve to clients over Thunderbolt.

http://support.apple.com/kb/PH17001?viewlocale=en_US&locale=en_US

Thanks...
Are you saying two MP6,1's can be interconnected via a Thunderbolt cable and transfer data back and forth without using Apple's Target Mode ? Why use X Server unless that is a technical requirement for serving data across Thunderbolt using IP. If not then a simple file sharing is all I require, much like can be done using ethernet for Macs connected to a LAN.

 

[goMac]

Thanks...
Are you saying two MP6,1's can be interconnected via a Thunderbolt cable and transfer data back and forth without using Apple's Target Mode ? Why use X Server unless that is a technical requirement for serving data across Thunderbolt using IP. If not then a simple file sharing is all I require, much like can be done using ethernet for Macs connected to a LAN.

OS X Server gives you a bit more capabilities, and it's only $20 on the app store. So if you're willing to buy a Mac Pro, it's not a bad investment on top of thins. It gives you better user management, more control over storage locations, etc.

Yes, don't use Apple's Target Disk mode. Set it up as a server instead. Target Disk Mode totally wasn't meant for this, and buying a Mac Pro is the least efficient way to do that anyway.

 

[bxs]

Did some testing today at home with two Thunderbolt-1 equipped Macs...

I directly connected my MBP8,3 (17-inch late 2011, 480 GB SSD, 16GB RAM) which has a single Thunderbolt-1 port to my iMac (27inch late 2012, 1TB Fusion, 20GB RAM) which has two Thunderbolt-1 ports with a single Thunderbolt cable.

I ensured both Macs had their AirPort/Wi-Fi turned off so that the only connection between the two was via Thunderbolt.

Using Finder both Mac could see each other via the Shared devices.

Then on the iMac I connected to the MBP and transferred a 20 GB file. At first the data rate was around 800 to 900 MBytes/sec (using Activity Monitor). As the kernel file cache became exhausted the data rate fell off to around 150 MB/s.

I then decided to use the AJA System Test on the iMac to read a 20GB file from the MBP. The MBP has 16GB RAM and the iMac has 20GB RAM. So the kernel cache on both Macs is not quite the same.

The AJA results for doing this is attached.

Pretty impressive if you ask me.

This coming Friday I will perform a similar test at the office where I will have 4 Macs; a MBP8,3, and two iMac 27" models to connect up via Thunderbolt to a MP6,1 which will have at least 3 Thunderbolt ports open. Then will perform some simultaneous file transfers between these Macs to see how things hang together. Of course for BIG files the slowest part will ultimately be the source and/or receiving disk.

 

[bxs]

I followed the above testing using a smaller file of 5 GB in size. I chose this as it meant the complete file could be held in the kernel file cache buffer on both Macs. I ran AJA again and results posted below....

This time without disk getting into play the transfer rate was a steady 450 MBytes/sec. That is, the i/o involved only kernel file cache and the Thunderbolt network.

 

[goMac]

A Mac Pro disk should push somewhere above or below a gigabyte a second, which Thunderbolt can sustain. But that's going to be divided among the number of active users. The Macbook Pro is still a SATA3 based system, so it's much slower than a PCIe Mac Pro, so I'd look forward to better performance in the Mac Pro.

If you ever want to use external storage but sustain the same speeds, that might be tricky. You'd want to have at least two SATA3 SSDs in a solid RAID configuration. Or go down the Fiber Channel/SAN route. It sounds like you're basically building a poor macs SAN here, which I mean in the nicest way. I'm guessing the biggest possible downside is that IIRC running fiber will be cheaper than running Thunderbolt cable.

Also, depending on what the final prices come out to, this will give you the same performance over ethernet cable:
http://www.sonnettech.com/product/legacyproducts/echoexpressse_10gbeadapter.html

 

[bxs]

You have that right. I am looking for a least cost solution to meet my requirements. The Sonnet solution is something I was looking at over past 2 days. I agree, it's something that will cost a few pennies but may well be the answer. I will be talking with Sonnet tomorrow to make sure I understand their products capabilities and limitations.

Thanks for responding with useful advice.

 

[bxs]

Going the Sonnet route to gain 10GbE between 3 Macs would be as follows.

1) MacPro6,1 (server)
2) Two MP5,1s (clients)

Sonnet products required
a) Sonnet Echo Express SE II (provides 2x TB-2 ports, 2x PCIe card slots) - $499
b) Sonnet Presto 10GbE 2-port PCIe card for the Echo Express - $799.95
c) 2x Presto 10GbE 1-port cards; one for each MP5,1 - $800

Twinax cables (5meter), Qty 2 - $200

Total comes to $2,300.