[CentOS-devel] SPARC build machines perhaps available soon

[Lamar Owen]

On Saturday 27 August 2005 19:08, Peter Arremann wrote:
> Probably won't work. The boards you have aren't compatible with the CPUs.
> Boards come in 83/90 and 100 Mhz versions... If you get a board with 336Mhz
> cpus, it will run at 83Mhz and the cpus have a clock multiplyer of 4...
> Adding 400Mhz modules to it will not make a difference - the cpus will
> report as 400Mhz but the clock speed will show as 336.

The EX500 boards are all 501-4882 83/90/100 boards.  In the E6500 the 
Gigaplane can run up to 90MHz, and won't run at 100MHz (length of the 
centerplane traces; also the reason load boards are required in the E6x00 and 
not the E5x00 and lower, as their centerplane is smaller (the E5500, E4500, 
and E3500 are all the same size; the E3500 is single-sided).

However, there are some twists here that are really funky.  Investigating, the 
400MHz 8MB cache CPU's run a 5x multiplier (80MHz Gigaplane) in E6500's, and 
a 4x multiplier in 100MHz Gigaplane systems (E[345]500).  The 400MHz/4MB 
cache module has to run at 4x only.  So, no, I can't run the 400/4MB modules 
in the 6500, at all.  But they can run in the 3500's or the 5500.  They won't 
run on the older CPU cards, either, which is OK.   Only the cards in the 
E3000 and the E6000 are impacted by that; might consolidate to the 6000 and 
load it up with 336's.

Hmm, very interesting.  Probably limit myself to 14 400/8MB in the 6500 (the 
three cards in the 5500 plus the 4 already in the 6500 that all have the 
400/8MB modules)  and put the four 3500's CPU modules with the 400/4MB CPU in 
the 5500 (which will work fine).  Then I can rotate the 336 modules around to 
the 6000... :-)  Fun.  Looking at one of the E3500's CPU cards now... two 
336MHz (501-4363) CPU's and 2GB RAM...  Since the 6500 already has 400/8MB 
modules, don't have to worry about the Clock+ upgrade, or the Flash PROM 
upgrade, either....

I'm going to have some fun next week... :-)
-- 
Lamar Owen
Director of Information Technology
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC  28772
(828)862-5554
www.pari.edu