Are the ATA problem any worse than those of the slower Beige with large HDDs
It should be fine if you use the stock drive with it. It's a different problem entirely than what the Beige G3 had. It's unstable on any drive with UDMA, which is most drives after the blue-and-white was launched. (It
also has the LBA48 limitation, but you're going to hit the UDMA limitation before you hit LBA48 capacities.)
The Rev-1 B&W can also only have one disk on its main hard disk channel.
The Beige's main limitation is the whole 8-gig thing. It doesn't become unstable with UDMA disks, to the best of my knowledged.
Given the nature of the IDE problems on this system with "newer" drives, a Rev-1 B&W would be a good system to put a SATA/IDE/SCSI controller in and skip the onboard entirely, if you can.
I figure even a 300MHz rev,1 B&W board is better than anything in Beige?
I'd say it depends.
Of course, the Beige didn't have the same kinds of IDE problems the RevA/1 Blue-And-White did, so there's that in its favor. If you need something to put a G4 upgrade in, the blue-and-white will be better because of its faster bus. If you need OS X, same deal, except for mostly that you're not wasting all the hardware in a beige that OS X can't use. (a/v, the not fully accelerated onboard Rage, serial/localtalk.) The Blue-and-white also has USB, which is nice and 10/100 ethernet, which is nice, even if it's mostly meaningless under classic mac os. So if you need a MacOS 8/9 box
specifically I'd say it's kind of a wash because just around that point is where OS 9 starts to fall off in terms of getting tangible day-to-day benefits out of more performance.
So, like, it really depends on what the machine is for. Both systems are upgradeable, so it's not like the IDE is going to cause you trouble, unless you already have all of the slots spoken for and none of them is something you can boot from.
Another option if you need more out and out performance is to just advance to a G4 motherboard. You'll get better
everything as a base for whatever it is you're doing.
CMD PCI646U2 ATA controller on my board with only a passing nod to (dead link) the 640 variant LEM claims to be the cat's meow. 640 would be an earlier rev, no?
Mmmm. Here's what
wikipedia says:
The CMD chip on Rev. 1 logic boards is PCI646U2 and on Rev. 2 logic boards is 646U2-402
So, both chips are the PCI646, it's just that the revisions are U2 and 402, with 402 being newer.
Wikipedia also has a more detailed description of the exact failure/problem mode the RevA B&W exhibits.
LEM's page doesn't mention a 640 at all, although it may have been updated at some point.