So I find it odd that you're now a CF proponent...
I'm not, but I also think people should be fully informed when evaluating the various options. People keep repeating like it's gospel that DOMs are fundamentally different and "always better" than CF cards. And that's technically not true; they're just CF cards in a funny package.
To be clear, here, I'm not saying that packaging difference is "worthless", mind you: it if of at least some value that the manufacturer is willing to mostly guarantee the unit work when plugged into an ATA controller that doesn't specifically know anything about the PCMCIA flash extensions, and bad/cruddy PATA/CF adapters are definitely a thing that can ruin your day. With a CF card you *are* technically rolling the dice whether the manufacturer of either your card or the adapter screwed up somehow, there are also some other edge case considerations, like the "removable" flag that's going to be set on most cards causing issues with specific OSes and whatnot.
But on the flip side, new DOMs usually cost significantly more than the same amount of CF, new DOMs, especially in larger sizes, are likely to have the same compatibility issues as large/new CF cards (bad support for CHS addressing, for instance), and, again, the *interface* is exactly the same in terms of speed and transfer mode support, so it's delusional to assume that a DOM will always perform better. People should know what they're really paying for.
I seem to recall you heavily promoting SD to IDE adapters over CF cards a couple of years ago, due to your bad experience with CF (
"In my jaded experience CF cards are junk.")
To clarify this, and it's a big clarification, my beef with CF cards is specifically with how scattershot
their compatibility is with 8-bit XTIDE subsets (XT-CF) is. At one point I when through a box of two dozen
industrial CF cards in various sizes between 128MB and 2GB, pulled from old network appliances testing them for compatibility with my particular XT-CF cards (of two different designs, one a straight rip of the lo-tech one, the other a homebrew I designed using GALs) and only about a third of them from two specific OEMs reliably passed a data corruption stress test.
*Every* SD-IDE adapter I've tried, both 40 pin and 44 pin, I've tried in this same situation, has worked flawlessly. Thus I'm firmly convinced that whatever you think of the concept of PATA-SD as a general purpose solution for old IDE adapters in this particular edge case the chip used in the Sintech-style adapters is a safer choice for supporting this particular protocol variation than any random CF card, and thus why I recommend them.
Here's the thing, though: every single one of the CF cards I tried from that box of failures tested *flawlessly* when connected via the same PATA-CF adapters I was using with the XTIDE card to one of those universal USB-to-PATA adapters. IE, they all formatted perfectly and showed no sign of data corruption when exercised via a full 16 bit IDE port in "True-IDE" mode. Thus I actually have no gripe against them for use in the sort of "486 or better" computer you mentioned, and I would guess (and there's some threads on Vogons that support my suspicions here) that on these newer computers any performance difference you see between a CF and "DOM" is going to be entirely up to the attributes of that particular device.
... And that's the irony here, isn't it? The OP is asking about DOMs for use with
XTIDE class adapters. XT-CF subsets fall into that category, so... I dunno, have you tried a 40 pin DOM with an XT-CF card? I actually have no idea if it works, either sometimes or always, because I haven't tried that myself. My vague guess would be that they *might* work, since as I've explained, they're using CF chipsets and 8-bit support is part of the CF standard, but I also highly doubt they've tested it because these devices are, after all, specifically designed to be used in standard 16 bit IDE ports.
So, sure, my recommendation to the OP would actually be to use a PATA-SD card adapter for this class of machine because, in my experience, the performance of these adapters is excellent, as is the compatibility, which I cannot say for random old CF cards. And then everyone can flame over that again.
I disagree about "limited write durability", and performance is relative.
Everything I've ever pulled a DOM out of (and I do have a small collection of them, but they're all useless 44 pin ones with reversed connectors; I could technically try one using my homebrew XT-CF that I designed to direct-plug 44 pin PATA-SD or PATA-CF sleds into, but I'd have to solder a different connector onto one and it's not worth it for a tiny DOM that may or may not work) is the sort of thing that the only processes that that ever touch the DOM are booting, firmware updates, and a little light logging. So, no, performance doesn't matter.
A modern SSD with a SATA/IDE adapter will wipe the floor with both. But that's overkill for a lot of vintage gear.
Yes, probably, although with the fastest CF cards (and, sure, there might be PATA DOMs just as fast) the limiter will probably be the speed of the IDE port anyway. Also, don't forget, even today there are *really cruddy* modern SSDs in circulation (dirt-cheap little MLC M.2 or MSATA modules you'll find in some chromebook-level machines) that aren't going to blow the doors off of anything. But again, given the OP is asking for something compatible with XTIDE, who cares. Even the slowest flash device will do the job...
And for laughs, I did try, and no, the PATA-MSATA bridge I bought to stick in a Powerbook G4 didn't work with my 8-bit XT-CF card.