Me too!
tecneeq: thanks, I've been cross compiling the kernel and whatnot a bit (that's how I did the kernel hack that I think enables the djmemc bank configuration). I was able to get an hp300 bootloader built that works for my setup and a netbooting hp300. Unfortunately, it's not an exact comparison since the hp I'm using maxes out at 48MB, but at least it's an 040 vs. 040 comparison. The hp300 port seems to be pretty stable under memory pressure and large memory allocations, although unfortunately it's swapped in my case instead of physical on the mac68k machine. I could try reducing the mac's memory down to something comparable and rerun the test to see if it panics.
The 650 and 800 with a stock ROM work with up to 32MB per bank, with 2 banks / SIMM slot, and 4 SIMM slots. So that gives 256MB, plus the 8MB onboard for 264MB. To get that, you need 128MB SIMMs and then just lose half the RAM due to the ROM's lame djmemc configuration. Same deal with the 610, you just only have 2 SIMM slots. This is all the same as the 605, it's just the ROM initializes the 605's djmemc correctly, which is all I'm really doing: copying the 605's configuration.
As for not worrying about RAM, you're not going to get a faster backing store than RAM. And with 520MB, you can fit quite a bit. Like putting your objdir in RAM, which would make linking as fast as it'll ever get.
Plus, it's my thing. Coercing the kernel into reconfiguring the memory controller is waaaay more interesting to me than building packages.
If it happens to help, great!The ram is recommended by trag, and is fine with macos and a/ux, and with all my poking at the memory controller from macsbug. So I'm pretty confident in the RAM at this point. This is the system I used to develop/test all the 040 and djmemc ROM mods I've done, which include using huuuuge RAM disks and all kinds of other fun stuff.
Now that I've got a diskless hp300, I'm thinking of putting macos & the netbsd booter in ROM for the IIfx and running that diskless too. Being an 030, it'll be slower, but doesn't have the ROM addressing limitations I've encountered on the 040's.
Trash80: the 630 can take 128MB SIMMs, they just have to be the special ones. link