dos is limited to 2gb per partition. meaning, your 40g hard drive would in theory could use 20 letters. c: - > u: if my mental alphabet is right.

Scsi is more fun in my opinion. I'm about to add one to my 386. That way, I would only use ONE IRQ for hardrives and cd drives, and not 2. Also the "enhanced" fast floppy controller is a plus.

Only dos up to 6.22 is limited in this way. In Dos 7 and others u can use FAT32

Now in my pc for old games i have the 40gb disk with 3 partitions, main 30gb Fat32, 512mb fat16 for swap & one 8gb for ext2

Works perfect,but im wonder a scsi disk would give me fast experience in win3x or some dos games/app that use hard disk too much

I ask because a scsi disk is expensive & i dont want to spend money for nothing

thanks

If you're that interested in speed, why don't you just get a 486? Depending on where you are, it will probably be cheaper, and quite possibly less troublesome to set up.

I seem to recall it has also been mentioned that SCSI drives make a lot more noise.

I used Scsi drives with dos and windows 3.11. Except for noise and costs this did not add anything useful. Add Ram and use a ram drive for speeding up Win 3.x cache.
Scsi will also add another bios and more drivers that will take boot time and memory.

From my understanding scsi is supposed to use less cpu? or is it more to do with the chipset on the card be it isa or scsi, on my ide future domain card under windows 95 its listed as a scsi device, I wonder if its the more or less the same as a scsi in terms of cpu use because of its onboard chipset with enhanced ide.

On an older system like that, SCSI is the way to go. My 486 has a BusLogic BT-445s w/ Seagate 420MB drive, I can get 10MB/s burst and I'm pretty sure you're not even going to come close with any kind of IDE setup on that bus. Besides, SCSI is just cooler. If you need an ISA SCSI card, PM me, got a BusLogic /w a floppy controller. It's ca. 1993.

When I first switched from IDE to SCSI on my 386 eons ago, I remember it "feeling" noticably faster in Windows 3.11, esp. when loading programs. I still have the system operable and use it with an AHA-1520B (Seagate SCSI drive and 2X SCSI CD-ROM).

The SCSI drive isn't that loud, but to find an older SCSI drive which doesn't have a high pitched squeel (due to overuse) on eBay will be difficult. All my SCSI drives are quiet, it they weren't I'd decommision them.

Apparently, in my case at least, the difference between scsi and ide isn't that great. The first picture is using a plain WD 6gb hard drive on a nice ide controller. The second is using an adaptec aha-1542b controller with a 9gb 10,000 rpm scsi hard drive. (U160)

I need to find a better benchmark. Maybe one that will display cpu load during hard drive access. Any suggestions are welcome. I'm going to re-bench the hard drives on a faster system and see if that makes a difference. I want to see if its a cpu bottleneck or isa or a combination of the two.

that's an odd result you've got there. Then again, UDMA2 and U160 SCSI are both pretty damn fast interfaces for a 386. Most 386 machines in the day would have been using PIO mode IDE, or SCSI 1 or 2.

The big advantage of SCSI back then was over PIO mode IDE, which is pretty CPU intensive- I think this is probably what feipoa is referring to. UDMA IDE modes close this gap a fair bit.
Would be interesting to try these drives on a 486 motherboard with both PCI and ISA controllers, and see if the PCI bus is significantly faster for the SCSI drive.

As for benchmarks, Norton Utilities for DOS has a couple of hard drive benchmarks but I don't think they are any more detailed than Speedsys, I think they just give you a raw number.

Yes, Doughnut King is correct, I was refering to PIO vs. SCSI on my 386.

I don't think your result is all that bad. The two HD speeds from SpeedSys which I tend to look at are Buffered read speed and Linear read speed.

You more than doubled your buffered read speed using the SCSI interface and increased your linear read speed by nearly 75%. You've also reduced your random access time by a whole order of magnitude.

Boot into Win3.11 and see if you 'feel' the difference.

A PCI-based DMA (like ATA33+) vs. SCSI on a 486 would certainly be an interesting benchmark.

Well I don't have a stand-alone scsi card apart from the one i'm putting into my 386 so I decided to test the drives on my dual slot-1 that I saved from oblivion a little while back. First off, is the scsi drive. I did change the cable from a 50 pin to a 68. I *might* do a test with a 50 pin cable if people desire or if they want the same controller and not the 7896 thats onboard.

ANYWAY... first up is the scsi drive:

yea, slightly better numbers than before. In fact, I could swear I heard the drive do this: http://www.youtube.com/watch?v=JJGojSQusYg ^.^

And this is the WD drive on the same motherboard:

It is also a huge improvement over the 386 score. So I'm of the conclusion that the bottleneck is the cpu itself. It looks like only so much data can go through a 40mhz processor.

We'd really need to see that ISA SCSI card in the PIII machine to see how CPU limited the 386 is. ISA SCSI @ ~10 MHz vs. PCI SCSI at 33 MHz would naturally be quite different.

Attached is a SpeedSys image of a 486's performance using the same series Ultra2 SCSI (adaptec 2940U2W) PCI adapter, yet the HDD scores of the 486 surpass those of your PIII's. So it is difficult to guess just where the CPU bottleneck comes into play.

yea it looks like the adapter is the bottleneck. Is there a bios update for it? ugg. looks like I have another reason to get a bios flasher... BAH.

I was looking at other cards, and this came up:
AHA-1522B
http://www.ebay.com/itm/350162768611

However I noticed something in the tech specs on Adaptec's website:

"Maximum ISA Bus Data Transfer Rate: 3 MByte/sec"

Which is what I was getting if I look back on the 386 setup. 😜 I'm going to have to hope that I can get more than 450MB on this card. I dont care if I get all 9gb, Hell, if I get limited to 2gb I wont care. what with dos 6.22's fat partition size limit.

2 gig should be good, however, I've used the seatools before and haven't had a problem getting > than that. I went with a 420MB SCSI in my 486 and, unfortunately, it's too small. 🙁

If it makes you feel any better, I have almost the same ISA SCSI card and get about half the linear read speed on my 386; using an AHA-1520B -- I didn't see the need for the floppy connector on the SCSI card since I'd still need another ISA controller card with serial ports, which most have the floppy connector as well.

I attribute this to your system having a much faster harddrive (Ultra160), whereas my harddrive is a standard 50-pin 4 GB Seagate Barracuta. Maybe there are other reasons as well?

I think the only other way to increase your throughput on the ISA bus is to overclock your ISA bus and hope all the cards cope well. I tried this and the results were problematic. Everything seemed like it was working well, then the case started to smell of IC burn. I quickly shut things off, but to my horror, my SCSI card wasn't being detected upon reboot. I removed all ISA cards, reinserted, then reset the AT clocks to where I had them. Luckily, eveything seems to work still.

I think if you're looking to optimise your 386 further, you might want to look into a Cyrix 386-40 instead of the AMD unit. The Cyrix/TI TX486DLC/E-40GA contains 1 KB of L1 cache, which can be enabled by a simple program at boot time. I've attached a SpeedSys image. The SpeedSys score of my Cyrix 386 system is almost double that of your AMD 386 with L1 cache enabled. I guess SpeedSys doesn't check for a 1KB cache block, so it doesn't show up on the charts, but is factored into the SpeedSys score still.

Here is my 386DX40 with a Future Domain enhanced ide card with a 20gig maxtor 7200rpm ata 133.

Nomal settings

This is with the ISA bus running at 10mhz (I think).

Your not going to get more than around 3meg per second out of the isa bus, I guess it comes down to seek times, we're talking 1/1000ths of a second is it something your going to notice?

The ugimage store doesn't show the images, better put the somewhere more user friendly

Your 386 monster has to be one of the, if not THE, fastest 386 out there 😀