Usually Adaptec cards were pretty easy to get going, however, in this case you've got a Fast-Narrow SCSI card on the PCI bus (capable of 10mbytes/sec) and a basic Narrow SCSI card on ISA (the 1505 will do 5mbytes/sec... it was designed for slow things like scanners, cdroms and zip drives).

If you really want to go SCSI (and it can be a good boost on old machines), I'd maybe hold out for an Adaptec 2940UW which will do Fast (10mbytes/sec), Ultra (20mbytes/sec) and Ultra Wide (40mbytes/sec) and has the benefit of both 50pin and 68pin headers (the latter of which will accept drives right up to Ultra-320 standards).

That said, of the two cards, if the Advansys has an onboard bios that makes it bootable, then I'd go with that over the ISA based Adaptec.

Did you happen to check out my hardware list in the World's Fastest 486 post (link below)? I have found that Adaptec 2940U2W PCI cards work well in M919's and in other PCI-based 486s. The advantage of the 2940U2W over the 2940UW is that it allows for harddrives in LVD mode and up to 80 Mbytes/sec transfer. It has two connectors for running seperately connected 50-pin narrow SCSI and 68-pin Ultra LVD SCSI hardware.

You can use Adaptec SCSI Bench to compare your transfer speeds. On a 40 MHz bus 486 (Cyrix 5x86-120), I've seen speeds of 36,000 KByte/s in Windows NT 4.0, while using a 2940U2W on a PIII, SCSI Bench got up to 70,000 KByte/s. You should be able to source a 2940U2W on eBay for $10.

I've run Ultra320 and Ultra160 harddrives on this controller for years and am currently running a 136 GB Seagate drive from the 2940U2W in a 486 server. You can also attach a SCSI narrow DVD/CD-ROM to the 2940 to boot from bootable CD/DVD's directly through the SCSI BIOS. If you want to go really hardcore, I've tested out some modern SATA DVD burners on the 2940 (and in a 486) using a SATA-to-SCSI narrow adapter; it worked fine.

I've tested the M919 with Windows 3.1, 95, and 98SE using an Adaptec 2940U2W and didn't have any problems booting into the OS. The M919 does have problems with the 2940U2W if you try to run Win2000. This is more of a M919-related bug; identical hardware in another PCI-based 486 work fine in W2K.

did you try any bios updates from adaptec to see if that corrects the problem?

I remember having a buggy 2940UW Pro card, but at the time there was no BIOS newer than what it had, so I gave up on it because it locked up on POST
so I've been using plain 2940UWs with the 3.10 BIOS since 😀

I'm still wondering when SCSI drives started to become slower btw. I'm tempted to try SCSI on an old rig, but I don't want a loud machine standing next to me.

Tetrium wrote:

I'm still wondering when SCSI drives started to become slower btw. I'm tempted to try SCSI on an old rig, but I don't want a loud machine standing next to me.

I have an Adaptec 2940 ultra scsi with a Seagate barracuda 7200rpm 2.1gb hard disk installed in my Pentium Pro system. Reason I did this was of course my obsession with being period correct while having the fastest ca. 1996-1997 hardware in my rig. It is indeed very loud, making a noticeable whine when it cranks up- which I find very nostalgic - but which might piss someone who is bothered about quiet pcs off to no end 😜 😁 ...

iv`e been rooting through my boxes of stuff and found a couple of
more adaptec cards one is a
19160 and the other is a 29160n
also found a pair of ibm ddrs-39130 9.1 gb hard drives
just got to find my scsi cd roms now 😲

Tetrium wrote:

I'm still wondering when SCSI drives started to become slower btw. I'm tempted to try SCSI on an old rig, but I don't want a loud machine standing next to me.

They didn't. ATA/SATA drives became faster and have crept in the workstation/server market at the low end, but comparing apples to apples SCSI drives are still faster and more robust.

The notion that SCSI harddrives are noisy is somewhat dated. Many of the 37-300 GB 10K Seagate Cheetah harddrives are whisper quiet, but there are a few older revisions of these that I would classify as audibly noticeable. I have 5 of the Seagate 10K Cheetah's (37, 73, and 146 GB varieties) that are currently running and are less noisy than the combination of case, CPU, and power supply fans. I don't even hear the seek/write crackle when working with these machines.

The latest revision models of a particular Seagate series are often the quietest. For example, a Seagate SCSI harddrive with model ST3146707LW will have a generation number of 7 (the last number in the string of the model number). I've personally noticed significant noise reduction going from a generation number of 4 or 5 to a 7 (where all other model numbers were the same except for the generation #).

All 50-pin SCSI narrow Barracuda harddrives I've used have had a high-pitched spin noise. The dB level of the pitch generally increases with age. Early Ultra2-LVD Seagate Cheetah harddrives didn't have quite as bad of a spin pitch, but had deafening read/write head noises, much worse than IDE drives of the same era. I remember back in 1998 when I got my first 9 GB SCSI Ultra2-LVD harddrive. I was the coolest geek on the block. I foolishly thought it would be convenient to put the computer in my bedroom -- bad idea. I found it horrendously difficult to sleep with its seemingly random read/write panic attacks. It woke me several times in the first month of use. It could be heard crackling 100 meters away and across rooms.

SCSI times have fortunately changed and I would highly recommend this modest little upgrade to any 486/586 user. The quietest SCSI drive I had was probably a 73 GB, Seagate ST373307LW. I got it on eBay many years ago, probably 2003-ish. I specifically remember being pissed off when I plugged it in and turned it on; it was so quiet I thought it was broken There was zero sound. While huffing and puffing with anger, I noticed the drive showed up on the SCSI BIOS display and all was well. The drive may have been new when I bought it.

@ TheMAN
This was awhile ago, but I recall that I had the latest firmware available for the Adaptec 2940U2W card (FYI, only retail versions of the card are updatable. Dell-branded 2940U2W cards won't work with Adaptec's firmware updates). I believe this was a case of the M919 bus mastering blues. I also have the 2940UW card which sported the same issues in W2K w/M919. Shuttle HOT-433 also has this problem w/W2K and PCI SCSI.

@recoil2525
The Adaptec 19160 is a great card as well, but if I recall correctly, it didn't work in any of the 486's I tested. It would be overkill anyway. I use the 19160 in my dual Tualatin 1.4 GHz box. It is not clear to me what the differances are between the 19160 and the 29160N -- the specs. look very similar. The 2940U2W is at least era-correct for the owner of a fast 486 who wasn't all itchy about getting a Pentium.

@megatron-uk
For the low-to-mid use server market where excessive storage space wasn't a high priority, one or several of the 300 GB, 15K RPM, Ultra320 SCSI drives would still be suitable (e.g. ST3300655LW or LC).

im kind of new to this scsi thing so i decided to try it out after recently aquireing a load of stuff from a servis enginer that usesed to work for dec/compaq/hp .

What would strike my fancy is if someone ran a SCSI vs. SATA comparison on a 486.

As an example, compare the throughput of an Adaptec 2940U2W (Ultra2-LVD @ 80 MByte/s) using any 10K Ultra160/320 drive vs. that of a Promise SATA150 TX2plus (SATA @ 150 MByte/s) using any 10K SATA drive.

Then re-run the performance comparison, but this time allow for many simulataneous read/writes to the harddrives.

Any volunteers? A faster 486 is preferred, say a Cyrix 5x86-100, 120, 133 or an AMD X5-133, 160 or an Intel DX4 (16KB WB) at 100 or 120 Mhz. Windows NT 4.0 would make for a good host for such a comparison considering both of these PCI cards contain NT 4.0 drivers and are known to work well on PCI-based 486s.

The SCSI would win hands down in terms of usability - the cpu utilisation required for ATA/SATA to match the transfer speed on such a low power cpu would mean you couldn't do anything else at the same time.

megatron-uk wrote:

The SCSI would win hands down in terms of usability - the cpu utilisation required for ATA/SATA to match the transfer speed on such a low power cpu would mean you couldn't do anything else at the same time.

Yup that true back in thoses days the SCSI was only way to go

While the suspected winner is obvious, it would be nice to have some numbers. For completeness throw in PIO-4, ATA-33, and a few other SCSIs, then chart the results.

The presumed winning order on a fast 486 might be,

1. Ultra2-LVD SCSI (80 MB/s)
2. Ultra Wide SCSI (40 MB/s)
3. Ultra SCSI (20 MB/s)
4. SATA-150
5. Fast SCSI (10 MB/s)
6. ATA-33
7. PIO-4

Experimental results always speak louder than hearsay. It would be interesting to see where SATA-150 and ATA-33 met up with SCSI on the 486 bandwidth chart. I guess we have no ambitous takers?

I suspect that there's probably not much between 1, 2 and 3 - a 486 just doesn't have the memory bandwidth needed to shift those kinds of numbers around. SATA-150 is likely to be no slower in terms of real-life data transfer rates, but you'll not be able to do anything else at the same time if you use such a system for heavy IO work (file serving, database, scanning etc).

A chart of transfer speeds is not really going to give you much insight - all things being equal you'll top out at the maximum transfer rate of the bus (Fast SCSI theoretically slower at 10m/sec compared to the 16m/sec of PIO-4), the disk device (highly unlikely) or the memory bandwidth of the cpu.

Charting transfer speed against cpu utilisation would be a much more interesting observation. That 16m/sec figure of PIO Mode 4 sounds good compared to 10m/sec SCSI, but you would never choose to use such a system in the real world.

after playing about most of day with the scsi idea i was using the advansys abp-3925 pci becauce of the built in bios just canot seem to get it to work .the machine reconises the card and i can get into the utility but it don`t see the drives .i tested the card in another machine and it works fine shows the drives lets me format them and do other things. ive tryed various bios settings on the m919 motherboard but still no luck . i also tryed a bigger chip amd dx4-100 and uped the ram to 64mb but still not playing .its as if the motherboard dont like the card .going to have a look on daft bay see if i can find Adaptec 2940UW amd have a go with one of those .

feipoa wrote:

While the suspected winner is obvious, it would be nice to have some numbers. For completeness throw in PIO-4, ATA-33, and a fe […]
Show full quote

While the suspected winner is obvious, it would be nice to have some numbers. For completeness throw in PIO-4, ATA-33, and a few other SCSIs, then chart the results.

The presumed winning order on a fast 486 might be,

1. Ultra2-LVD SCSI (80 MB/s)
2. Ultra Wide SCSI (40 MB/s)
3. Ultra SCSI (20 MB/s)
4. SATA-150
5. Fast SCSI (10 MB/s)
6. ATA-33
7. PIO-4

Experimental results always speak louder than hearsay. It would be interesting to see where SATA-150 and ATA-33 met up with SCSI on the 486 bandwidth chart. I guess we have no ambitous takers?

Parallel ATA (PATA)
IDE / PIO 0, 3MB/s
ATA-1 = ATA, IDE , PIO 2, 8MB/s
ATA-2 = EIDE aka Fast or Ultra ATA / Fast IDE, PIO 4/DMA 2, 16MB/s
ATA-3 Was dropped
ATA-4 = Ultra ATA/33 aka UDMA/33 , Ultra DMA 2, 33MB/s
ATA 5 = Ultra ATA/66 aka UDMA/66 , Ultra DMA 4 / 80-wire, 66MB/s
ATA 6 = Ultra ATA/100 aka UDMA/100 , Ultra DMA 5 / 80-wire, 100MB/s
ATA 7 = Ultra ATA/133 aka UDMA/133 , Ultra DMA 7 / 80-wire, 133MB/s

Small Computer System Interface (SCSI)
SCSI-1 = SCSI-1, aka Narrow SCSI, 5MB/s
Fast SCSI = SCSI-2, 10MB/s
Fast-Wide SCSI = SCSI-2 / SCSI-3 SPI, 20MB/s
Ultra SCSI = SCSI-3 SPI, aka Fast-20, 20MB/s
Ultra Wide SCSI = SCSI-3 SPI, 40MB/s
Ultra 2 SCSI = SCSI-3 SPI-2, aka Fast-40, 40MB/s
Ultra 2 Wide SCSI = SCSI-3 SPI-2, 80MB/s
Ultra 3 SCSI = SCSI-3 SPI-3, aka Ultra-160, Fast-80 wide, 160MB/s
Ultra 320 SCSI = SCSI-3 SPI-4, aka Ultra-4; Fast-160, 320MB/s
Ultra 640 SCSI = SCSI-3 SPI-5, aka Ultra-5, 640MB/s

Serial Advanced Technology Attachment (SATA)
SATA, 150MB/s
SATA, 300MB/s
SATA, 500MB/s

Solid State Drives (SSD)
There are min diff form factor host interface: Serial ATA, PCI Express, PCI, Fibre Channel, USB, Parallel ATA (IDE/EIDE), SCSI (Parallel/Serial).
SSD, Slow as 1MB/s to well over 1500MB/s

Keep in mind that memory cards like CompactFlash (CF), Secure Digital (SD), Memory Stick, and xD-Picture Card were all originally designed for digital cameras but later found their way into other device like USB, Phones and so on which typical there interface is generally 4/30x times slower than what is available on SSDs interface.
Slow as 1MB/s up to 200MB/s with USB3 interface

The Problem with old IDE that where used since the days 80286 all way to some of the first model Pentium is there controller didn't support ATA-2 mode if I recall rigth and even add-on device so there for Narrow SCSI or Fast SCSI and Wide was about 2x faster then IDE even on ISA bus which you limed to 4.7MHz and VLB was petty much on it way out door even know it pettey fast 33/40 to 50HMz on thsos old 486 board, 2nd problem is 486 bios didn't always see some PCI IDE add-on card if your lucky and have a 486 with PCI slot.

IDE and Serial ATA 300MB/s never did catch to SCSI, How ever PCIe Solid State Drives blow door off SCSI Interface.

recoil2525 wrote:

after playing about most of day with the scsi idea i was using the advansys abp-3925 pci becauce of the built in bios just canot seem to get it to work .the machine reconises the card and i can get into the utility but it don`t see the drives .i tested the card in another machine and it works fine shows the drives lets me format them and do other things. ive tryed various bios settings on the m919 motherboard but still no luck . i also tryed a bigger chip amd dx4-100 and uped the ram to 64mb but still not playing .its as if the motherboard dont like the card .going to have a look on daft bay see if i can find Adaptec 2940UW amd have a go with one of those .

What mean you can't a Adaptec 2940UW jee there must be well over 40 on eBay.

@recoil2525
Are you familiar with how to setup SCSI? Did you ensure termination of the host controller as well as on the hard drive? Host controller termination is setup through theSCSI BIOS while hard drive termination can be done on the harddrive with a jumper, or with a terminated cable. Ensure no two devices on the cable have the same SCSI ID.

@megatron-uk
You made a good point in that our throughput is FSB-limited. My 486 system does clock the SCSI performance to 35 MB/s, so there would still be an advantage of 40 MB/s SCSI over 20 MB/s SCSI, but maybe not 80 MB/s SCSI over 40 MB/s SCSI.

yes i checked that .i tested the same card cable drive combo in a diferent machine worked fine i also tryed with the adaptec 29160n and that was the same im wondering if its a problem with motherboard or bios .becauce if had issues with the pc chips m919 and vlb video cards .some times it works fine and other times it wont boot but put a pci video card in and its fine. maybe its time to get a decent motherboard 😲