Booting MP6,1 from disk attached to 27" Thunderbolt

[bxs]

I have a MP6,1 with three displays attached as follows...

1) TV connected to HDMI (Bus 0)
2) An Apple 27" Thunderbolt display connected to Port6 (Bus 0)
3) A 20" ACD with Apple's DVI-to-MiniDisplayPort connected to Port3 (Bus 1)

I have a clone of my 10.9.2 MP6,1 system on a 1TB FW800 LaCie Rugged disk.

I attach this FW800 to the FW800 port on the backside of the 27" Thunderbolt display and boot up from it.

When I do this I'm finding that with a TV connected to HDMI (Bus 0), an Apple 27" Thunderbolt display connected to Port6 (Bus 0) and a 20" ACD with Apple's DVI-to-MiniDisplayPort connected to Port3 (Bus 1) I'm only getting the 27" Display to light up.

As an alternative I created a clone of my 10.9.2 MP6,1 system on a 1TB LaCie Thunderbolt disk. I then connected this LaCie Rugged 1TB Thunderbolt disk directly to Port2 (Bus 2) on the MP6,1. Booting up from the LaCie I find all three displays will light up nicely.

It appears to me that under 10.9.2 booting from any external disk attached to my primary 27" Thunderbolt display will not allow me to have multiple displays; 2 or 3 or more. Is this a documented limitation I wonder, or is it a bug.

Somehow with this configuration for booting the system there's insufficient power going to the TV and the 20" displays even though they are both directly connected to the MP6,1 ports.

I suspect if I were to connect the 1TB LaCie Thunderbolt boot disk to the backside of the 27" Thunderbolt display it still will not allow the TV and 20" to light up. I have not tried this mind you.

 

[jerryrock]

Displays should be at the tail end of a Thunderbolt chain and should be connected to different Thunderbolt busses with the nMP.

http://support.apple.com/kb/HT6068

 

[bxs]

The Bus 0 can support 2 displays when HDMI is being used. So I have TV and 27" Thunderbolt display on Bus 0. The 20" mini display port is connected to Bus 1.

This configuration is supported by Apple and works without issues when I boot from the internal boot volume of the MP6,1.

The problem arises when I boot from a disk attached to the Apple's 27" Thunderbolt display. Only the 27" is discovered and lights up. The TV and the 20" do not.

The TV and 20" simply do not get a video signal.

All other Thunderbolt devices attached to the MP6,1 such as LaCie 2big Thunderbolts and my Burly 5-bay eSATA Port Multiplier are discovered and can be accessed. The Burly is accessed via a Sonnet Thunderbolt-to-eSATA adapter and an EXpressCard|34.

 

[jerryrock]

It still looks like you are overtaxing bus 0 that has to support the external TV via HDMI, the 27" Thunderbolt display and the Firewire 800 boot drive.

Why not move the Thunderbolt monitor to Thunderbolt bus 2, which is not currently supporting a display?

 

[bxs]

It still looks like you are overtaxing bus 0 that has to support the external TV via HDMI, the 27" Thunderbolt display and the Firewire 800 boot drive.

Why not move the Thunderbolt monitor to Thunderbolt bus 2, which is not currently supporting a display?

Hmmmm, OK will try that. Thanks.