On Tue, Jan 09, 2001 at 07:55:24AM -0800, David S. Bach wrote: > I have several questions about installing on a PowerMac 7500. Before2. The PM7500 has a MaxPower G3 300 processor card. Is it necessary to tell BootX anything about this?Don't think so, it should be transparent ...
The G3 processor card should execute the code transparently but maybe the cache control is not transparent...
I have a PowerLogix G3 upgrade card with 1M of backside cache in a PowerMac 7600. It works fine with Linux of course. Note that on my system the PowerLogix G3/G4 Cache Enabler control panel reports that BootX is present under MacOS and it has a checkbox to "Configure BootX L2CR on Reboot". Selecting this somehow sets BootX to enable the PowerLogix cpu's backside cache. From this control panel, while in MacOS, I can set the backside cache speed as a ratio of the cpu speed (1:2, 2:3, 1:1) and set the G3 board to boot up with the cache enabled. I have no control over the PowerLogix cache from within Linux.
It is nice with variable clock upgrade cards to be able to boot with the backside cache disabled so that you can recover quickly when testing for the cache's upper speed limit. You know when you've passed the limit because the computer bus faults and stops running!
[BTW I found that I could run the PowerLogix G3/366 processor card at 366 MHz quite well but then the backside cache could not run any faster than 1:2 (180MHz). I got better overall performance by setting the cpu to 300 MHz and running the cache at 2:3 (200MHz). ]
David may need to check with the MaxPower manufacturer to find out if the cache is fixed speed (?) and always enabled (?). If not, how is it controlled?
Good luck David! Debian/ppc is proving to be a very good distribution. -- Garry Roseman <mailto:memphis@macconnect.com>