Nearest I have handy,
FUJITSU MPF3153A 15GB - 23.1 MB/s
Seagate ST33221A 3227MB - 9.3 MB/s

I'll put my old Seagate Decathlon 850 to the test over the weekend (don't have OS installed on it at the moment) and post some results. Generally I would imagine that it's usually the old slow IDE interfaces that hold things back in a lot of old systems. Memory cards have much faster access times than HDDs, very much like a proper SSD in that respect, and this probably offers more in terms of a performance increase than the actual transfer rates, unless the SD cards are very slow of course. A class 4 card should be "at least" 4MB/s, which in all honestly would probably be enough for DOS gaming and such. However, a faster SD card isn't that much more expensive, and a class 10 card would most likely start to hit the limits of what a 486 IDE controller could comfortably handle. I mean, theoretically PIO mode 4 can do 16.67MB/s, but I have CF cards capable of much more than that, and they cap out at less than that speed in Speedsys at least.
Only screenshot I can find from Speedsys at the moment shows one of my CF cards doing only a bit over 3.3MB/s @ 0.70ms access times, but that is the slower one of my CF cards, so the transfer speed of that could be limited by the card.

I think the card itself would be adequate, although SD cards are not really meant to be used for random access. However the consensus seems to be that the IDE->SD adapters slow things down a lot. Even so, a modern SD card would probably be just as fast or faster than an old HDD. I remember my old 486 with a 250MB Quantum HDD had a sequential transfer rate of about 2.5~4MB/s and something like 16ms of access time (maybe more? not sure).

That said a CF card is the way to go due to its native IDE interface.

On a 486 the fast HDD's have transfer rate about 1.8MB/s and around 11ms random access time (Quantum 1080A - 1GB size). With a CF card you get around 3MB/s and random access time of 0.1ms. It's quite noticeable - like SSD's today.

This has probably been answered a million times, but: Is this a limitation of the BIOS to read hard-disk parameters? Because otherwise I don't see why one could not simply partition a modern PATA HDD with a small partition that the BIOS could work with, and then benefit from the huge buffers and extremely low seek-times and throughput.

It is a hardware limitation of the controller. Commonly on 486 they can do MW-DMA 2 which es equivalent to PIO-4 speed wise. If you have a PCI 486er and find a later SATA controller which actually works, you could exploit the PCI bus transfer rate. However, if you reach about 40 MB/s on a 486er it is already top speed.

You can use larger, more modern drives, in combination with Dynamic Drive Overlay. That might work for you.

Another option is using IDE to SATA adapters, and capacity limited, Seagate drives. While I haven't tried this on a 486 class machine, it's my preferred storage solution for all my machines, tried and tested and hasn't let me down.

On 386 and 486 machines though, I usually stick with IDE to CF adapters because the performance is easily sufficient for DOS games. I wouldn't worry so much about transfer speed. It's the super low access times that give CF adapters the speed.

philscomputerlab wrote:

You can use larger, more modern drives, in combination with Dynamic Drive Overlay. That might work for you.

Another option is using IDE to SATA adapters, and capacity limited, Seagate drives. While I haven't tried this on a 486 class machine, it's my preferred storage solution for all my machines, tried and tested and hasn't let me down.

On 386 and 486 machines though, I usually stick with IDE to CF adapters because the performance is easily sufficient for DOS games. I wouldn't worry so much about transfer speed. It's the super low access times that give CF adapters the speed.

I also use CF->IDE with a DDO but I find very restrictive that you can't just connect the card to a modern pc and copy files. I guess there is no other way though, you can't get larger-than-expected HDD's recognized correctly even if you only intend to use a valid partition size.

konc wrote:

I also use CF->IDE with a DDO but I find very restrictive that you can't just connect the card to a modern pc and copy files.

can you explain your problem with more detail? i am hesitating whether i should use a sd card or cf card.

konc wrote:

you can't just connect the card to a modern pc and copy files

Unless you use a card reader? 😕

konc wrote:

I also use CF->IDE with a DDO but I find very restrictive that you can't just connect the card to a modern pc and copy files. I guess there is no other way though, you can't get larger-than-expected HDD's recognized correctly even if you only intend to use a valid partition size.

I heard about this problem, but didn't encounter it. In fact, I was surprised that it "just worked", and mentioned this during one of my tutorial video.

What DDO are you using?

There are many kinds, but the two main ones are EZ-Drive and Ontrack.

They existed as retail versions, but also as, free, OEM version from all the manufacturers, such as Maxtor, Segate, Western Digital. Though I found that most of them will work on CF cards, and only some will actually not work on other manufacturers.

There is also a trend that newer DDO versions all went with Ontrack, and the older versions used EZ-Drive.

On my site, I have reviewed a few of these. Included are also download links, and I've tested them all. They fully work.

http://www.philscomputerlab.com/maxtor.html

http://www.philscomputerlab.com/samsung.html

http://www.philscomputerlab.com/seagate1.html

http://www.philscomputerlab.com/western-digital1.html

The newer version of Ontrack require machines with lots of memory. 16 MB to be exact. If your machine has that much RAM, you can go with the latest versions, which have a nice graphical interface. These late version, based on Ontrack, also offer the capability of Booting from CD-ROM, which can be very handy.

But there should be no issue with reading these on a USB CF card reader. One challenge is when you create the classic 2 GB FAT + 6 GB extended (split into 3 drives) FAT partition setup typical for MS-DOS 6.22 configurations. Windows will only show you the first partition. Linux, and maybe, OS X (not tested), show you all four partitions.

Sorry for the long post. I'm quite passionate about these things and CF storage has always worked really well for me. So I like to help whenever I can.

In this video I provide an overview of storage options: https://youtu.be/Edmg43t28jg

And here a tutorial for installing a 32 GB CF card in a 386. Creating a single FAT32 partitions for LOTS of games 😀 https://youtu.be/sI7U9LYbt28

philscomputerlab wrote:

I heard about this problem, but didn't encounter it. In fact, I was surprised that it "just worked", and mentioned this during one of my tutorial video.

What DDO are you using?

i am going to buy only a 8gb cf(or sd) card for a 486 rig, so there shouldn't be any problems right?
and does it work right in windows95osr2/98? would it be recognized by windows as a fixed disk, or as a removable storage device? i've heard some people experienced the latter.

noshutdown wrote:

i am going to buy only a 8gb cf(or sd) card for a 486 rig, so there shouldn't be any problems right?

I've used a 4GB Transcend card in a PCI based 486 motherboard (SiS 496/497 chipset) and there were no problems. In fact I think that particular motherboard probably supports up to 8GB or even more. However, older motherboards might have problems with that capacity. If you have the chance also get a 2GB card just in case.

noshutdown wrote:

and does it work right in windows95osr2/98? would it be recognized by windows as a fixed disk, or as a removable storage device? i've heard some people experienced the latter.

As a fixed Hard Disk Drive from my experience, since a proper CF card has an actual IDE interface. If a CF card connected to an IDE interface isn't detected as a HDD then I would say it isn't a proper CD card, but some kind of cheap knockoff.

noshutdown wrote:

philscomputerlab wrote:

I heard about this problem, but didn't encounter it. In fact, I was surprised that it "just worked", and mentioned this during one of my tutorial video.

What DDO are you using?

i am going to buy only a 8gb cf(or sd) card for a 486 rig, so there shouldn't be any problems right?
and does it work right in windows95osr2/98? would it be recognized by windows as a fixed disk, or as a removable storage device? i've heard some people experienced the latter.

Should work fine! I haven't used SD cards however, only ever CF cards.

Windows 95/98 works fine as well 😀

Another possibility is SCSI. Adapter 2940UW/U2W controllers are cheap on eBay and it's fairly easy to find old 4GB SCSI drives, especially if you don't mind an SCA connector. I picked up a couple for $5/ea on eBay not too long ago.

I honestly see no downside to using CF cards myself. They are native IDE, they are fast and completely silent. The fact that they are not very expensive and brand new as well is another bonus.
The Seagate HDD I've got, I bought because in a moment of pure nostalgia I thought it would be cool to have the "good old" HDD noise coming from my retro rig, but at the end of the day, I've ended up not using it on a regular basis.

Right, as I promised, I'd benchmark my Seagate Decathlon 850 IDE HDD to get a reference speed to compare CF cards against.
Here are the speedsys "Full Test" results.

I'm sure a SCSI disk would perform quite a bit better, but then again, it would probably produce even more noise than this one does.

Hope this helps with the choice of storage solution.

+1 for CF cards, get one that mounted on an I/O bracket and its easy to swap over.
If you don't want to bother with DDO you can have say 1 CF card with Dos, 1 with Win9x, etc, or if your system is limited to 500 MB you can quickly swap "game cartridges" over

chinny22 wrote:

+1 for CF cards, get one that mounted on an I/O bracket and its easy to swap over.
If you don't want to bother with DDO you can have say 1 CF card with Dos, 1 with Win9x, etc, or if your system is limited to 500 MB you can quickly swap "game cartridges" over

Exactly that. I have different CF cards for MS-DOS, OS/2 Warp and Windows 95. If I need to add some more games or music to my retro rig, I can just pop the CF card into the card reader on my main computer and copy it straight across. It saves me a lot of hassle.
You could also argue that CF cards improve the CPU performance of the system, as there will be less wait time for disk access, meaning that the CPU will be freed up to work on actually running the game/program much more quickly than with a mechanical drive.