Setting RAM priority

[ancalimon]

What is the command to use at startup-sequence to set the priority of the ram installed in my A4000T?

For example what should I do if I want Amiga to use ram on CyberstormPPC first, mainboard second and zorro last?

Should this command be before loadmodule or blizkick and also setpatch?

[zipper]

Amiga does it automatically, using the fastest first.

[ancalimon]

Originally Posted by zipper

Amiga does it automatically, using the fastest first.

How does it understand which one is fastest? And is there a way to check what their priority is?

At the moment I have a 3630 in my A4000T 4x32mb ram (16mb) ram onboard and ZorRAM 256. I don't know which one is faster.

[mark_k]

You can use a system monitor tool like Scout, that should show memory priorities. There are some programs on Aminet which can be used to set priority of memory regions.

Sometimes the default priorities are not optimal. For example with Kickstart 1.2/1.3, slow RAM at $C00000 (typical A500 trapdoor RAM) has a higher priority than true Zorro II fast RAM. Hence Commodore's FastMemFirst utility which fixed that.

I would have thought that CPU board memory would be faster than Zorro III RAM. But Commodore's memory design wasn't the best, so who knows? You could experiment by running some kind of memory bandwidth benchmark, once with priority of CPU board RAM set highest, once with Zorro III set highest and see if there's any difference.

[ancalimon]

Thanks. I forgot about Scout. I can see that 16mb onboard ram has highest priority and it makes everything faster.I was having problems with green~yellowish screen at boot up and it turned out a simm had problems. Replaced it with an 16mb one and it's working.

Will be using it like this until my CyberstormPPC is fixed. Maybe I can track my old 3640 and use it instead of 3630.