adaptec AVA-2825 does PIO mode 4

VLB controllers with the Promise PDC20630 supposedly do MWDMA2 (as opposed to the PDC20230 which does only up to PIO 4 AFAIK).

As for UDMA2... PCI is your best bet here... If you *must* have it in VLB form, then get a VLB SCSI card if you can find one, but I don't suggest it.

Tekram DC-680C/CD does mode 4 with a BIOS update

jheronimus wrote on 2021-11-05, 19:21:

Tekram DC-680C/CD does mode 4 with a BIOS update

You mean PIO mode 4, correct?

MWDMA2 has the same theoretical transfer rate as PIO4 (16.7 MB/sec), but it is in reality faster.

Find a card with a PDC20630... They're not that rare. I've not yet tested whether EIDE2300.SYS works properly with OEM cards that have the PDC20630, but I don't see why it shouldn't.

Maybe it's worthwhile asking someone here to dump their EIDE2300+ VLB Bios.

Thanks, found a EIDE2300+ locally, I appreciate the tip.

https://web.archive.org/web/19970607082226/ht … LUS-Launch.html

"EIDE serves as a realistic way to extend the life of the IDE interface and supports the growth of the 32-bit VL bus architecture which we believe will continue to evolve and grow despite the emergence of PCI. EIDE definitely serves the high-volume needs of stand-alone Windows and multimedia users who want flexibility and performance but do not require the additional cost or complexity of the SCSI environment."

Okay, so that didn't age well, the 32-bit VL PCI quickly killed it off.

The jumper manual lists a PIO IDE speed options as 0, 2, 4 and 6? I found a sandisk article that lists PIO MODE 6 as 25MB/sec is that accurate?

https://stason.org/TULARC/pc/hard-disk-floppy … wo-IDE-dri.html

https://kb.sandisk.com/app/answers/detail/a_i … dma-information

I've used the EIDE2300. I remember the manual said that its VLB IDE interface could run in DMA mode, but the interface to the system is always PIO.

Just stumbled across this product, I think it's made my wish list. Found one for 250USD. I'll keep an eye out.

20MB/sec transfer rates and up to 16MB Cache

https://web.archive.org/web/19971011212939/ht … DE4030PLUS.html

RobDos wrote on 2021-11-05, 22:17:

Just stumbled across this product, I think it's made my wish list. Found one for 250USD. I'll keep an eye out. […]
Show full quote

Just stumbled across this product, I think it's made my wish list. Found one for 250USD. I'll keep an eye out.

20MB/sec transfer rates and up to 16MB Cache

https://web.archive.org/web/19971011212939/ht … DE4030PLUS.html

Good luck finding one for cheaper. Caching IDE controllers are expensive. VLB ones even more so.

yeah I have one of those cards and likely wouldn't let it go under 200ish

but, it uses the 20230 chip so

pic from some random online listing

I have both of these Promise cards and they’re not that super fast. It might be motherboard BIOS dependent, but the fastest configuration option using the EIDE2300Plus is MWDMA set via driver and I can just beat 11 MB/sec. Good enough. The onboard jumper selections are for pre-EIDE speed settings.

I can recommend the cache controller only for very slow disks. The 20 MB/sec figure is cached speed; the disk interface is very slow, PIO-0.

indeed, none of these controllers other than the adaptec 2825 in my experience ever performed particularly well on EIDE disks

the adaptec card performed "well" but SCSI disk performance was always considerably better, though I'll grant I've never tried one with a CF card. raw data transfer rate is never what matters, things like seek time or multi block transfers etc matter far more

How about a ROM dump please for the VLB 2300+ for those of us with a ROM-less OEM card?

libby wrote on 2021-11-06, 15:59:

indeed, none of these controllers other than the adaptec 2825 in my experience ever performed particularly well on EIDE disks

the adaptec card performed "well" but SCSI disk performance was always considerably better, though I'll grant I've never tried one with a CF card. raw data transfer rate is never what matters, things like seek time or multi block transfers etc matter far more

What's the best VLB SCSI controller in your opinion. I never really played with them much, as I was more focused on EISA and PCI.
I do have an AMI Fastdisk, which I still haven't gotten around to testing. That one might be the only SCSI VLB controller with cache.
As far as I know, wide SCSI for VLB doesn't exist.

Anonymous Coward wrote on 2021-11-07, 02:09:

What's the best VLB SCSI controller in your opinion. I never really played with them much, as I was more focused on EISA and PCI.
I do have an AMI Fastdisk, which I still haven't gotten around to testing. That one might be the only SCSI VLB controller with cache.
As far as I know, wide SCSI for VLB doesn't exist.

no wide or ultra SCSI for VLB that I know of

would say adaptec 2842VL is likely the best bet, only other card I know of is a buslogic one I've never tried (I have one... somewhere), and some random cards which used stripped down adaptec chips

Need identification for VLB IO card with IDE, Floppy, Serial, Parallel AND SCSI

another caching controller

another (NCR chipset)

in my personal opinion using a caching controller to read is probably of limited benefit on VLB or EISA because you have bus mastering already and most of the benefit would be found only doing certain types of burst reads, if using a modern SCSI drive, relatively speaking, the same reads would occur from the 8-16MB drive cache and you would only be benefitting getting faster reads out of the controller's cache until it's exhausted

writes would be where you'd benefit, at cost of stability inherent to VLB being kind of crap

These caching controllers are ok at best - reads from cache is fast, writes are pio3, populating cache is also slow.
Adaptec 284x is allright too.
Both are mediocre compared to Promise eide 2300 plus and Holtek HT6560B.
These two can deliver 13-18mbs, especially the Holtek, but is more fussy than eide2300plus - does not like each and every hardware configuration.

As libby mentioned above - the rules of engagement differ between mechanical hdds and cf cards.
The cf card's fast random access largely reduces the perception of delay by these legacy interfaces.

libby wrote on 2021-11-06, 15:59:

indeed, none of these controllers other than the adaptec 2825 in my experience ever performed particularly well on EIDE disks

the adaptec card performed "well" but SCSI disk performance was always considerably better, though I'll grant I've never tried one with a CF card. raw data transfer rate is never what matters, things like seek time or multi block transfers etc matter far more

Good to know that the AVA-2825 is something more than an expensive curio. I only tested the SCSI part - I guess I should test it again, this time with EIDE 😀

Anonymous Coward wrote on 2021-11-07, 02:09:

What's the best VLB SCSI controller in your opinion. I never really played with them much, as I was more focused on EISA and PCI.
I do have an AMI Fastdisk, which I still haven't gotten around to testing. That one might be the only SCSI VLB controller with cache.
As far as I know, wide SCSI for VLB doesn't exist.

I use SCSI in all my retro systems because I only had IDE back then, even if I was terribly fascinated with SCSI - so that was a good time to fix that 😁

Especially on older systems (286/386), SCSI is a lifechanger. Big drives just work, and you don't have to deal with weird BIOS implementations. On the other side you're missing the thrill of getting that IDE support in the BIOS working, which is definitely part of the experience of having older systems.

But enough banter - the fastest SCSI controller I have (though I have only Adaptec-branded controllers, I wonder how the other brands fare?) is the 2842A. Should be a slightly newer version of the 2842VL and that's what I have in my 486 system.

mockingbird wrote on 2021-11-07, 01:18:

How about a ROM dump please for the VLB 2300+ for those of us with a ROM-less OEM card?

Dumped. BTW, I have the EIDE2300+ installed in my socket 3 system as well as the paper manual and drivers. I have Win95 installed on a Quantum Fireball EL2.5. With the Win95 driver installed (ptivgapi.mpd) but no DOS driver, I was getting 6.6MB/s in both DOS (speedsys/qdimark) and Windows (HDTach). If I load the DOS driver (EIDE2300.SYS) with the /m0:8 or /d0:a switch then my performance in DOS goes up to 10-12MB/s, but my performance in Windows goes down to 3.2MB/s. Weird eh?

In every case, HDTach showed high CPU usage, so I assume that DMA is not used under Windows.

bakemono wrote on 2021-11-07, 09:42:

Dumped. BTW, I have the EIDE2300+ installed in my socket 3 system as well as the paper manual and drivers. I have Win95 installed on a Quantum Fireball EL2.5. With the Win95 driver installed (ptivgapi.mpd) but no DOS driver, I was getting 6.6MB/s in both DOS (speedsys/qdimark) and Windows (HDTach). If I load the DOS driver (EIDE2300.SYS) with the /m0:8 or /d0:a switch then my performance in DOS goes up to 10-12MB/s, but my performance in Windows goes down to 3.2MB/s. Weird eh?

In every case, HDTach showed high CPU usage, so I assume that DMA is not used under Windows.

Thank you sir. Much obliged. Those numbers are good to know as well, thanks for those. Now I'm curious about Windows 3.x, there's a driver for that too in their package, but yea, how does that work exactly if the DOS driver has already been loaded and Windows is just running atop of DOS...

Regarding DMA and Windows, do you have the "DMA" box checked in the HDD properties of device manager (or is that only a Windows 98 thing)?

libby wrote on 2021-11-07, 05:17:

... would say adaptec 2842VL is likely the best bet, only other card I know of is a buslogic one I've never tried (I have one... […]
Show full quote

Anonymous Coward wrote on 2021-11-07, 02:09:

What's the best VLB SCSI controller in your opinion. I never really played with them much, as I was more focused on EISA and PCI.
I do have an AMI Fastdisk, which I still haven't gotten around to testing. That one might be the only SCSI VLB controller with cache.
As far as I know, wide SCSI for VLB doesn't exist.

...
would say adaptec 2842VL is likely the best bet, only other card I know of is a buslogic one I've never tried (I have one... somewhere), and some random cards which used stripped down adaptec chips
...

In my opinion the 2842VL is not really a good SCSI controller. While the same chip is close to the 10 MB/s limit of fast narrow SCSI it does almost 19 MB/s in fast wide mode on a 2742W on EISA bus. But my fast narrow 2842VL does not even pass 6 MB/s.
A more through examination will follow in a few days.