MP 1,1-5,1 SLED positions left to right — 1, 2, 3, 4

[MacProRumours]

Curious as to whether the position of HD/SSD sleds makes any difference between slots one, two, three or four?

The presence of a non-bootable—and also unrecognised 8TB HD—in the left-most position, on start-up appeared to prevent the machine from advancing beyond the chime, despite the presence of a reliable bootable SSD next door (position two).

I had expected the system to boot from position two. There were non-bootable SSDs in positions three and four.

When swapping drives in one and two, the machine started up as normal.

My guess is that this may relate to either power-draw (ie. the large capacity HD), HD-vs-SSD in some way, or something else I've missed. I wonder if anyone has any comments about order or position of storage sleds?

Thanks.

 

[DeltaMac]

Choose your boot drive from System Preferences/Startup Disk.
Or, boot your MacPro while holding the Option key. Choose your boot drive from that boot screen.
I have always heard that slot 1 is the initial default, if no other drive is set as the boot drive.
Why did yours seem to hiccup during boot, when you moved the only boot drive to a different slot? Maybe you are correct about the high-capacity hard drive making the boot miss somehow.
Maybe someone with more experience with the older Mac Pros will have a better answer.
I am pretty sure that slot order does not determine boot sequence, at least not in any repeatable way.
I would think that if you have only one drive with a boot system, then the preferred slot for that boot drive is slot 1
Of course, that does not reduce the "value" of setting that boot drive in the Startup Disk pane.

 

[bmoraski]

This reminds me, Ill have to check my drive orientation but on occasion from a COLD boot my 4 TB Media drive is not recognized. I do a restart and its there. I just chalked it up to my ssd boot drive is too fast on boot to recognize. I have 3 drives installed. 1 TB ssd boot, 1 TB HHD backup and 4 TB HHD. Im very curious.