Try FDISK, partition it, then FDISK /MBR to ensure the MBR is correct. Then use FORMAT C: /S.
Also, there is a chance an SSD might need 3.3V (which molex->SATA adapters can't provide), but I guess that if this was the case it would not work at all.

Thanks a lot for the tip! I completely forget that! Mea culpa.

fdisk /mbr fixed the boot issue, so I get the SSD running in my Asus TXP4-X mainboard. That is a good thing. Install went fine even at 83MHz FSB (witch give 41.7MHz PCI bus clock) using Pentium 90 @ 125MHz.

However that is all for good things. Bad thing is, that the SSD will not using DMA at all and the speed is accordingly limited by CPU - see 93.3% CPU usage - to 7.2MB/sec.

This is laughable for SanDisk 120G Ultra II SSD, even run thru the adapter that support SATA (1) only...

I would like to mention that ONCE (just once!) I get the DMA running using PATA to CF adapter and that give me on same machine speed around 24MB/sec:

...with around 20% CPU usage. That might looks a big high, but remember that we are talking about Pentium 1 system, not i7 machine... 😀 Anyone have any ideas / solutions for that DMA failure?

Can you confirm that this particular adapter has working DMA support? Look up Phil's vídeo about storage options for old computers - he does mention that he was unable to get DMA working with some adapter models, but it works fine on the same computer with a different one - he even shows the adapters themselves.

Well, since I did not managed to run DMA on a HDD (Seagate 13G ST313021A), then the problem is very likely not with the adapter itself, but with the card. However the concern is valid and I take the adapter with the SSD to the ASRock 775Dual-VSTA mobo and run HD Tune there and we see what happens.

Good call. However I dubt that this will be the case, sadly.

So I tried it and the results are as follows:

This looks nice, but what is the terrible dip there? Does not make sense, no load was there... so I tried it couple of times and it was always there...

And on top of that, it progressively go worser till suddently I was running ONLY in PIO mode:

And it stays like that for now, no matter that I set in BIOS UDMA6 ... That suxx beyond words. I'm utterly disapointed and dismayed. I have no idea what is going on and mainly WHY the DMA mode died on me... I see no reason for it. I even resoldered all the "not so good looking" joints on the Gembird PATA to SATA bi-derectional adapter from with JM20330 chip, but no change in behaviour.

How one can "reset" the UDMA or force the DMA mode in Win? It always worked for me, except the Asus TXP4-X mainboard, witch appears to be cursed or something like that... I have no idea what to do. Maybe some chipset drivers are need for the i430TX chipset? And what could possibly cause this weird behaviour on the ASRock 775Dual-VSTA mainboard?

Looks like those adapters are not worth the trouble, have you tried using pci sata controllers instead?

AFAIK whenever Windows detects issues reading from an HDD it keeps track of a quantity of errors, and when this counter gets big enough it prevents the drive from activating DMA. Now, I'm not sure this is just for 2000+ or if Windows 98 did it, but I wouldn't doubt it. You can try deleting/uninstaling the IDE controller in the device manager, reboot, allow Windows to set it up again and try enabling DMA back.

Please check the following settings in the AsRock BIOS:

32-Bit Data Transfer

IDE Busmaster

V-Link Speed

IDE Drive Strength

IDE HDD Block Mode

I don't rememeber which setting exactly, but I do remember that there was one setting that caused disk caching to be very slow and the system sped up significantly after enabling it in BIOS.