Performa 5320: what clock speed?

[Franklinstein]

Also every 52/53/62/63xx came with a 256k L2 cache; it's soldered onto the same DIMM as the ROM, so you really can't not have it.

Aha, forgot that detail, thank you.

I bought a modified Color Classic with a 100MHz 53/63xx logic board and thought it wouldn't boot because of the empty ROM/L2 slot. Imagine my surprise (again) when I flipped the board over and spied some ROM chips. It turns out we were both right: the 52/62xx and early 53/63xx models use a combo ROM/256K L2 cache DIMM, but apparently the later 53/63xx models (logic board part number 820-0751-A) have ROMs soldered to the underside of the board and the L2 cache is again optional, using modules similar to those from the x100 Power Macs. No wonder Apple was having problems in the '90s; their supply chain must have been a total mess. 

 

[Franklinstein]

The saga continues: I bought a lot of 820-0751-A logic boards online recently and when the box arrived, it had a few surprises:

There are two different clock configurations of this board: 100MHz or 120MHz. The boards are unmarked in regard to speed ratings, but apparently they used a color scheme to differentiate: the 100MHz boards have a silver heat spreader, while the 120MHz parts have blue heat spreaders. Also, all of these boards use IBM processors. 

I attempted to install a L2 cache in a couple of these boards, but either it won't boot (with the IDT SOJ-style chips) or isn't recognized by any profiling utilities (with Motorola PLCC-style chips). Running benchmarks suggests that the L2 cache, when installed but unrecognized, provides no benefit, so either these things had weird special cache modules (that I can find no reference to) or all of my L2 cache modules are dead.

Another interesting note: when comparing various examples of the Quadra 630 and derivatives up through the 53/63xx series, there are often significant differences between suppliers of the various chips on the board.

For the Valkyrie, it seems the first and primary supplier was Sierra Semiconductor, then a good number of AT&T parts appeared in the later versions, and I have a single late-model board with a Chips-sourced chip.

Primetime is usually VLSI or TI in earlier models, with a Samsung version more common in the later models.

F108 is usually VLSI, but there are TI parts out there.

Capella is usually Fujitsu or occasionally VLSI. I found this the most interesting because I have never seen a Fujitsu-sourced ASIC in a Mac before.