[SunRescue] Help booting 64bit kernel on an Ultra

James Lockwood lockwood at ISI.EDU
Tue Sep 7 18:16:26 CDT 1999


On Tue, 7 Sep 1999, j. grubman wrote:

> My 1/170 w/ two 9 gig drives and a creator is exponentially cooler than 
> my old SS20 w/ dual HS 150's and the same disks. My bedroom was noticably
> cooler after getting rid of the SS20. 
> 
> Does your 140 have a fan (mine does)? For whatever engieering/design reason,
> Sun stopped using fans on the Ultra1 processors towards the end of production.
> I'm not sure if that fact has any bearing on how much heat they put out...

Sun replaced the CPU fans with very large (for CPU) heat sinks.  I seem to
remember the line of reasoning being that if you could get rid of an
additional moving part and keep the same temperature, then you would have
fewer points of failure.  I know that they had a rash of CPU fan failures
early on in U1 production when they used sleeve-bearing fans (they would
spin down on power-off and not spin back up).

AFAIK, the early and late CPU's have the same power dissipation specs.

As far as big heat producers, my SS20/712 with 4 sbus cards and maxxed-out
memory leads my pack.  I don't run an internal drive in that machine
though, it would probably bake itself in short order.  My AXi is a close
second but the addition of ducting inside the case has worked wonders.  I
hope PC case manufacturers get a clue soon.

-James







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