Amiga OS 3.2.2 RAM usage vs 3.1

[Jameson]

Hey guys, any thoughts on this? The reason I ask is I am a big fan of the new 3.2.x version of AmigaOS, however I am usually installing it on 020+ and 32MB+ Amiga's. I now find myself setting up a system for a friend and the system in question is a plain Jane A600 with 2MB Chip, 4MB Fast and an 8GB CF HDD.

I am tossing up whether to stick a KS 3.1 ROM with WB 3.1 and then something lightweight like BetterWB, or whether to fit a 3.2.2 ROM with OS 3.2.2. With only 4MB Fast RAM I can't really afford to use any maprom or fastrom function as I don't think it would be worth it to lose 512kb FastRAM.... but I guess if I can keep the initial boot down to around 1.2MB then an additional 512kb lost to substantially speed up the system is doable? Either way I would have just two partitions (System and Work) with minimal buffers to preserve FastRAM.

Also, how much WOULD mapping the ROM to FastRAM speed up a basic 68000 system?

Lastly, I know 3.2's revision of the FastFileSystem is vastly superior to the old implementations, however on a 68000 am I best using PSF3AIO or 3.2's FFS? PFS3 was always faster than FFS in the past..... but is that still true now?

Any thoughts?

 

[MJFletcher]

O3.2 uses more ram, the release notes mention it quite clearly. With 1MB ram (in A2000) it will 'just' boot from floppys. So not really suited for old style setups.

Pretty sure you need a MMU to remap ROM->RAM so not an option on plain 68000 anyway.

PFS3 is definitely still quicker than 3.2 FFS, at least of CF cards, not tried it on a HDD.

 

[Jameson]

Hey there. Yessum, I knew 3.2 used more RAM to get to a Workbench desktop, but I was wondering HOW much more RAM it used. 200kb? 500kb? With 6MB total RAM (2MB Chip and 4MB Fast), 3.2 is totally doable on this basic A600, but I am trying to decide whether it is WORTH going to 3.2 when the extra RAM used is balanced against the extra features etc.

Regarding remapping the ROM, you can do this without an MMU (even old programs like Relokick etc managed this on a plain 68000), and I am pretty sure 3.2 does this automatically if you are using a kickstart older than then version of 3.2 you are installing - for instance if you have 3.2.1 Kickstart ROMs and you then install the 3.2.2 update, I THINK it softkicks the new ROM image..... though it could be just using loadmodule to update just the parts it needs to (can't remember).

Anyone ever tested how much more RAM 3.2 uses to boot to a standard 640x256x4 Colour plain Workbench compared to 3.1?

 

[MJFletcher]

I think it's about 200kb Vs 3.1.4, I had that ROM in my 1mb A2000 previously.

Its LoadModule to replace just certain components am sure, my 64mb TF536 lost almost nothing running 3.2.1 (at the time) on a 3.1.4 ROM.

Putting the whole ROM in CPU local 'fast' on the TF536 makes a big difference,. not sure how much actually you can gain on 68000 'fast', just less DMA access blocking?, probably benchmarked and covered loads in old mags though.