Thanks for the explanation.

The reason I'm asking is that I did some benchmarks on my ZuluSCSI using a 16-bit Adaptec 1540B SCSI controller and it beat my PicoMEM on raw throughput on a 386, so I thought it may well be down to 8 vs 16-bit bus.

douglar wrote on 2025-09-01, 23:33:

FreddyV wrote on 2025-09-01, 17:59:

douglar wrote on 2025-08-31, 18:58:

I think the XTide project might have that need pretty well covered.

PicoMEM with my latest test firmware is now much faster than XTIDE, and it is even much faster on 8088/8086 PC (thanks to RAM to RAM copy and no IO)

So it sound like you are saying that XTide gets < 900KB/s using PIO transfers, but you are able to get something between 1MB/s to 2MB/s using MIO transfers, yes?

Does it use a buffer in an upper memory block to do the transfers ?

Hi,

900kb/s and more is impossible on an 8bit isa bus.

You are probably talking about xtide bios with a disk on an ide connector.

I talk about the 8bit xtide isa card
Yes, transfer is done via a buffer in ram

vetz wrote on Yesterday, 14:29:

Have there been any thoughts on a 16-bit version for increased throughput performance for 286+ systems? PicoMEM getting really good as an alternative to IDE to CF/SD (especially with all the extra features).

Nope.
Ian scott picoide is 16bit.
16bit isa is complex to do with a pico

vetz wrote on Yesterday, 18:17:

Thanks for the explanation.

The reason I'm asking is that I did some benchmarks on my ZuluSCSI using a 16-bit Adaptec 1540B SCSI controller and it beat my PicoMEM on raw throughput on a 386, so I thought it may well be down to 8 vs 16-bit bus.

Zuluscsi is doing only disk.

Scdi and ide use 16bit data, 4 bit address max and does only one think: disk

Isa is 8bit data 20bit address and io/mem signals, it is more complex to do...

vetz wrote on Yesterday, 18:02:

douglar wrote on Yesterday, 17:47:

vetz wrote on Yesterday, 14:29:

Have there been any thoughts on a 16-bit version for increased throughput performance for 286+ systems? PicoMEM getting really good as an alternative to IDE to CF/SD (especially with all the extra features).

I asked that question about 2 years ago. The answer at that time was that going to the wider bus would require more wait states on memory mapped features, which wasn't desirable.

But on a 16-bit computer the memory features are much less needed as almost all machines except the original 5170 already have minimum 640kb memory and its normally easy to expand it on the motherboard. I'd gladely trade it for increased disk performance on my 386. The disk/floppy features and USB mouse makes it usable even on a 486.

Exact.
Memory on 16bit isa for 16bit isa machines is useless And disk on 16bit isa is slow compared to an ide interface.

The nature of the picomem disk emulation make it really competitive already vs a 16 bit isa based disk.
Picomem can be seen like a really fast 8bit isa card.