Back in the windows XP heyday I had a crazy setup with a P4C800, a CT-479 socket adapter and a mobile cpu. This combined with a 15k scsi drive for the operating system was an incredibly beastly setup. If i was building an XP rig, I would probably do that again

aries-mu wrote:

Wow, I never put my hands on SCSI in my life before, that's why... […]
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EZFlyer wrote:

Flexibility and compatibility. Older versions may only allow boot from SCSI ID 0 or 1, don’t have autoterminate, individual settings per ID as opposed to global settings. You need a certain bios version for zip compatibility if I remember right. I think the 2940 needed 1.25+. If your rig is simpler, you probably don’t need to care as much. On mine, I want to set up every ID just how I like and switch boot devices from SCSI BIOS instead of having to rip out drives and change their IDs. I could use a bootmanager, but I have to research for scsi support.

Wow, I never put my hands on SCSI in my life before, that's why...

My plan would be:

PCI SCSI Controller → ACARD SCSI to IDE bridge → IDE to CF card adapter → UDMA7 super fast SanDisk CF Card

If you are going IDE anyways, you might as well just use onboard if available. SCSI to IDE introduces latency of it’s own, not that I think it would be noticable. Plus it’s a waste of $$$ on that adapter.

feipoa wrote:

For many in the retro computer landscape, doing something just because you can is reason enough. There is very little going on here that is actually practical. Uncommon and high-end hardware combinations spark excitement, which is more than half the hobby.

That is literally my motivation. Unfortunately, flexibility is key in my case. Trying to fix one problem and causing multiple others is a PITA.

Aries-mu,

One other thing that should be mentioned. Newer cards tend to run faster due to better microcontrollers. They have better optimizations and larger buffers. Also queuing for drives that support it. My SyQuest EZ135 is a heck of a lot faster on my 29160N than my 15xx (ISA). The drive only supports 5mb/s transfers.

luckybob wrote:

For dos games, its just dick waving. A CF card is more than fast enough. I personally use a 15K scsi drive in my IBM ps/2 setup. Its fsst, but noisy. If i had the option for a quick, quiet sata drive, I'd be all over it like a fat guy on a chocolate bar.

With the platter density that modern SATA entry level drives have achieved, you can saturate an ATA100 interface when using a converter. I'm not sure what SCSI can offer beyond that.

Coolfactor and headaches/achievements unlocked. Ultra ATA133 will saturate conventional PCI. SCSI at a similar transfer rate offers a bit more speed as the CPU doesn’t have to handle the commands, the microcontroller does it. I believe thats why SATA got a performance boost in AHCI mode, but that’s a guess.

feipoa wrote:

I've tried this. It is expensive, but it works. I think you're speed is limited by the ACARD bridge adapter and the CF card. What CPU will you be using?
The only place I have a U320 controller is on a PCI-X slot in a dual Tualatin 1.4 GHz system, along with PCI-X gigabit ethernet. The PCI-X slots are on a different bus than the regular PCI slots.

Woow! You've tried even this feipoa!! Yes, they're ridiculously expensive nowdays. Too bad I didn't foresee this hobby in the past, I could have bought them when they were cheaper.

And, you're right. When I first posted this post I didn't realize yet that the PCI bus would have been a bottleneck. Then it came out somewhere else in one the replies to some other my post.
So, basically, there's no reason to use a U320 SCSI controller in a PCI Pentium 90, Pentium 60, and even DX4-120 (the DX4 is still on paper, don't have it).

But thanks.

My conclusion, based on the precious suggestions of you all, is that to push such systems to the maximum possible edge they offer, given the PCI bus bandwidth, and without conflicting too much with the video card and a possible 3DFX Vodoo 1 3D card, an 80 MB/sec UW SCSI2 controller is the way to go. Hopefully I'll find a caching version, with about 16 to 32 MB of memory.

luckybob wrote:

those scsi bridge adapters are like $200+ right?
Scsi is stupid when you have PCI. Just get a sata2 card and a cheap chinese SSD. You are trying to hammer a nail with a jackhammer here.

Yes, they're unfathomably expensive! Shame on the tiny pieces of plastic board with a few tracks and a couple of chips on them, while a modern super-advanced motherboard which are basically computers cost less.

Yes, that kind of SCSI is stupid under PCI, when I first created this post I hadn't realized this yet (see my reply to Feipoa here above ↑).
Ahahahahah hammer a nail with a jackhammer here!!! (y) THAT'S EXACTLY THE FUN 🤣!

The goal is to push the Pentium(s) (60 and 90) and a theoretical (still to be purchased and assembled) Enhanced AM486 DX4-120 WB to the maximum possible limit, to make the fastest 486-computer (also literally, meaning with "486" printed on the CPU, so, 5x86s don't qualify) on the planet. About the I/O subsystem, where 486 computers range from 1 to 3 MB/sec (older IDE 486s) to 16.6 MB (EIDE PIO MODE4 486s) and to even 33 MB/sec of some Ultra DMA computers (more wouldn't help as the hard drives bottlenecked), with a UW SCSI2 fully filled up by a UDMA7 SanDisk Extreme PRO CF card (240 MB/sec real) via a SCSI to IDE bridge + IDE to CF adapter, we would have a 486 computer running its "hard drive" at 80MB/sec constantly all the time!! Can you imagine it? Can you imagine the apps and games that were made for those 3 to 16 MB/sec. performances? Can you imagine the benchmarks!!!!!

luckybob wrote:

leave that slot empty in the bios. So for one sata drive, leave the primary master slot open. Put the cd drive on the secondary master. If you have an ide drive connected, it will still prefer the onboard ide, but leaving the pri/master slot open, it gives the sata card a place to hook the sata drive into.
I did something similar with a 286 running both sata and MFM hard drive controllers.

• Wow, nice trick man!!
• And how in the freaking Laniakea galaxy supercluster in which we live did you manage to run SATA on a 286?????? (and what are MFM??? A new candy? forgive my ignorance 🤣). I mean did you find ISA SATA controllers? Or did you manage to build a DIY PCI-to-ISA converter?

oohms wrote:

I can't think of any real reason to have a super fast hard drive in a retro system. That said, maybe you can get an adaptec ult […]
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I can't think of any real reason to have a super fast hard drive in a retro system.
That said, maybe you can get an adaptec ultra160 card and a 15K scsi drive
https://storageadvisors.adaptec.com/en-us/sup … w/ez-scsi_3.11/
I'm not sure if this will work for your application, but if you already have the hardware it's worth a shot

Yes you're right oohms, please refer to my replies above for my overlooking the PCI bottleneck.
However, the very first requirement of a retro computer for me is to get rid of hard drives (which were my nightmares) and run them on modern smooth quiet fast solid state memories. That's the whole fun of it for me.

luckybob wrote:

For dos games...A CF card is more than fast enough. I personally use a 15K scsi drive in my IBM ps/2 setup. Its fsst, but noisy. If i had the option for a quick, quiet sata drive, I'd be all over it like a fat guy on a chocolate bar.

Bob, are you sure you have to dream about it? I mean, provided the controller is fast enough (and the SCSI to IDE bridge is at least a UW2 80 MB/sec type if the controller is SCSI, otherwise, go with UATA 133), if you get a SanDisk Extreme Pro CF Card UDMA7 via a IDE to CF adapter, you get performances that are waaaaay beyond any possible no-matter-at-what-speed-spinning cluttery SCSI hard drive! Or am I wrong?

yawetaG wrote:

oohms wrote:

I can't think of any real reason to have a super fast hard drive in a retro system.

Apart from using a retro system for tasks requiring a fast and reliable hard disk, such as audio and video editing, or running professional CAD solutions, there are none. And even then you'd be better off with a P3 or P4-based system...

Theoretically you're right yawetaG. However, as feipoa pointed out:

feipoa wrote:

For many in the retro computer landscape, doing something just because you can is reason enough. There is very little going on here that is actually practical. Uncommon and high-end hardware combinations spark excitement, which is more than half the hobby.

Retro-computing hobbies are not exclusively based on rationality and logic (wow, I feel like a starship captain dealing with a vulcan officer during a dangerous predicament) 🤣!
To me, the whole retrocomputing thing was born because old "rotating" drives have always been my nightmare, both in terms of speed (and noise) and reliability.
I was dreaming of solid state kind of drives way before they were released. In the early 2000s, I was scavenging the web looking for hardware ramdrives, and I had found a bunch of drives, the 5.25" ones were my favorite, with 4 to 8 SIMM RAM modules on them, and a SATA port. But they were so freakingly expensive!!
So, now, with all these SSDs, DOMs, CF and SD cards and plenty of converters/adapters to IDE, and such cards being super super fast, it's a philosophical concept: a past-future blend! Running an old CPU-based system like a 486 or a Pentium on such > net 50 MB/sec smooth and quiet solid state drives feels like having a 12 cylinders bi-turbo compressor squeezed in the trunk of an old Suzuki Santana.
I mean, if a Lamborghini gets to 300 kph nobody is surprised. But seeing that little Suzuki quietly hitting 900 kph (in the analogy with the computer world, being the Lamborghini the fastest hard disk possible, and the hyperdrived little Suzuki a modern SSD or card via adapter) has no equals in feelings.

Adaptec does not have 32bit disk drivers for win 3.1x for ultra2 cards (cards that use ASPI8U2.SYS for the dos aspi layer/68pin port is LVD/HVD). So if you want 32bit disk access/permanent pagefile/win32, 40mb/s is your top speed with ultra1 if you attach an ultra1-wide device. Scsi2sd and such adapters appear to all be narrow which would max at 20mb/s for ultra1. I’m not sure if SCSI to EIDE adapters support wide negotiation or not.

Edit: added that ultra2 cards have LVD/HVD.

EZFlyer wrote:

Adaptec does not have 32bit disk drivers for win 3.1x for ultra2 cards (cards that use ASPI8U2.SYS for the dos aspi layer). So if you want 32bit disk access/permanent pagefile/win32, 40mb/s is your top speed with ultra1 if you attach an ultra1-wide device

Oh gooosh! That's so too bad! What about non-Adaptech? Like if I recall LSI and others were making nice cards...

EZFlyer wrote:

Scsi2sd and such adapters appear to all be narrow which would max at 20mb/s for ultra1. I’m not sure if SCSI to EIDE adapters support wide negotiation or not.

Yeah, that's exactly why I didn't consider SCSI2SD, no point (mmmm... unless RAID... well let's not get too complicated). SCSI to IDE bridges, on the contrary, exist at least up to the U160 SCSI (ACARD bridges) for what I know... that's why I figured much better SCSI to IDE to CF rather than SCSI to SD...

I wish I had experience with LSI or BusLogic, but I do not. I just have a bunch of Adaptec cards. There are also Advansys cards, too, but I think those are an oem type card, but I only had one.

LSI is a top notch brand. I think adaptec bought out buslogic, but don't quote me on that.

Good to know! Thanks!!!

Another option is sticking with IDE and using SD to IDE adapters. I have found them to be far less trouble than trying to find CF cards that play nice - the only downside is that they don't like sharing the IDE bus with another device

I would really be looking at driver support as well - regardless of what you get. Windows 98, for example, is much faster if you can enable DMA for your drive

Aries-mu,

So I finally got a 2940uw to replace the 29160n. Found another problem with paging and 32-bit disk access in win3.1. Only the first two drives handled by BIOS in the system can be used for that purpose. If going SCSI, having any IDE disks will prevent that feature from working due to limitations in win3.1. I don’t think it’s a problem for later versions of Windows, but can’t confirm. I toasted my 95 install and have to start over.