Subject: Re: More raining and pouring VAXenbits!
To: Mattias Nordlund <>
From: NetBSD Bob <>
List: port-vax
Date: 01/16/2001 10:14:00
> > Anyway, who has power input requirements and cooling requirements
> > for the CPU chassis on the VAX 7000 line?
> I have no idea exactly what it uses, but the rack on "mine" have a note
> saying 5.5Kw, 12A V ~380-415. And on the main PSU i says 500VAC, 1A. And
> we are using a 3-phase 16A powercord to it.

Interesting... 500VAC 1A.  That implies 500 watts.

Most of the power losses in the thing seems to be regulator power.
The machine runs on 48VDC, with that power going in on the two large
cables (No. 6 guage or thereabouts).  The difference between 400VAC
and 48VDC is the tremendous loss in stepping down the power via the
regulators.  My guess is the actual machine only needs around 1000W
at 48VDC, plus the fan power.

> About migrating the machine out of the rack, I don't think you will be
> able to do that, there is nothing 19"-ish about it, and you need that
> monstrous fan that is in it to cool the cpu/mem-cabinet and XMI-cabinet.

Can you explain a little more about what each of the cabinet components
actually are?

A simple drawing of what I saw in the VAX 7000 cabinet I am trying to
get is something like:

                            CONSOLE I/O
               CPU BOX   +    I/O BOX
                       BIG FAN
               POWER INPUT

Any insights as to what the boxes actually are and what the power
input/cooling requirements of each box are, is appreciated.

> But if you can get the whole rack in to the house without your wife
> knowing, it's a mean machine =)



p.s.  Is the VAX 7000 a VAX or an Alpha?  The drives from the storageworks
      cabinet have Alpha Digital Unix P4.0 on them, and they boot and run
      fine on my Alpha 3000/300 crate!