[rescue] 480Mhz Cpu's in an Ultra 2 Chasis? Can it be done?

[Skeezics Boondoggle]

On Thu, 15 Feb 2007, Mark Brown wrote:

> On my Ultra-2 (Dual 300's) - can I replace these with 480mhz cpu's from 
> an E450?

As others have mentioned, that's almost certainly not going to work for a 
number of reasons.

I've never understood, however, why nobody has tried those in a 220R or 
420R - those ought to have the cooling and power to support the 480Mhz 
modules, whereas perhaps the desktop versions (U60 and U60) may not...

In the 220/420R, the 360Mhz modules run at a 3:1 clock multiplier and the 
bus runs at 120Mhz.  The 450Mhz modules run at 4:1 - with a 112.5Mhz bus.  
Why didn't they drop in the 480?  Yield?  Heat?  Power requirements? 
Physical size of the modules?  PROM issues?

If you actually have some of the (rare/expensive) 480Mhz US-II parts and 
are feeling frisky, I'd scrounge up a 420R and try that.  But don't blame 
me if the thing bursts into flames! :-)  I'd be very curious to know if 
anyone has successfully done that, though.  It seems a perfect match.

-- Chris