The fastest solution is a RAM drive/RAM disk, since it by-passes all bottlenecks.
That's what my dad used to tell me. He used that surplus memory in his XTs/ATs as a RAM drive on DOS.
This way, he didn't need to play disc-jockey with the floppy drives or wait for the squeaky MFM/RLL drive.
(HDD caches like Smart Drive weren't as popular of efficient yet. Old PC-Tools had one, I admit.)
The idea isn't exactly new, though.
Both Macintosh and Amiga users were already familiar with RAM drives in the 80s.
That being said, there also were physical solutions.
In the beginning, before PC Cards/PCMCIA memory cards or CF cards were used in embedded, there were RAM-based floppy drives.
They did act like real floppy drives, but were based on DIP/DIL RAM chips. They looked a bit like an EMS board (say Intel Aboveboard), just half the size.
The reason for this was that the RAM was expensive at the time and that the RAM drive's storage capacity was little (roughly 2MB or less; let's say 512 KB).
Such capacities could be mounted on the system as regular floppy drives, still. No need for a fixed-disk emulation yet, which would have been more complex.
On a 486 system, a caching IDE/SCSI controller could still be useful, maybe.
It does use RAM for caching/buffering and has an intelligent controller. The throughput may be the same as a CF card, but..
The caching controller might be tougher. If lot's of read/write requests occur, a CF card tends to start to stutter (seen that on Win98 rigs).
That's because it has little to no cache, was designed for linear (continuous) read/write operations. Most modern CF cards I've seen no longer seem to have that tiny 1KB cache.
Edit: You can also do caching in software, if enough RAM is available.
Solutions like Helix Multimedia Cloaking have a Smart Drive replacement that runs above 1MB, so it won't steel conventional memory.
But there are other solutions, as well, of course. Running a type of cache is needed for CD-ROM games, anyway.
Without caching, or a modern CD-ROM drive that has a big buffer, the game play will not be very smooth.
The problem with modern CD-ROM drives is, however, that they spin at a high rate. Whenever a track is being switched, the drive slows-down or stops and this gives you stutter.
This makes the gameplay worse than back in the day of single-speed and double-speed drives.
To fix that, the CD-ROM drive must be re-programmed to run at a slower, constant speed, so it won't be speeding-up/down everytime.
There are DOS programs like CDSPEED that may help, *IF* the CD-ROM drive in question supports manual override.
Edit: Utility attached. Good luck! 😀 🤞
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