VOGONS


First post, by Gahhhrrrlic

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I know several people have tried to get a 386 fast enough to play games like Doom but the general consensus is that the hardware simply can't play something that demanding at speeds that most are willing to tolerate. That's fine. Nevertheless there may be other applications and games which are a bit more marginal than Doom, which may be worth reaching for. To that end, I'm interested in which upgrade paths provide the best bang for the buck so to speak... not even in the economic sense but just in terms of how much of a speed gain you would get for the hassle of upgrading, what the risks or complications would be, whether doing so would eliminate a bottleneck, etc.

For myself I am starting with a pretty stock machine. The motherboard is an MB1333C-40CH
http://www.elhvb.com/mobokive/Archive/Biostar … b1333c-40ch.JPG
with a socketed DX33 (which I have since upgraded to DX40 but the crystal is limiting now). Soon I will be getting a ULSI 387 and my controller card is flaking out so I figured I may as well get a SCSI card and hard drive. Thing is I don't really know if the choices I'm making are addressing current bottlenecks or not and if so, how much of a gain they give. Should I be making other choices that I'm maybe not thinking of?

MOBO: The crystal is currently the problem here and I need to swap it to get 40 MHz on the cpu, ASSUMING that would even work
CPU: This is as upgraded as it can be already. I'm assuming this is a dead end now
FPU: Coming in the mail. Should help but mostly for scientific computing and financial apps.
RAM: 8MB right now. I have no idea the speed but I'm wondering if a ram upgrade to faster ram would help or more ram? Do 386s like more than 8?
CACHE: No idea what the board has in it now or whether the system would benefit from an upgrade. Any advice?
HDD CONTROLER: Currently a half-working IDE piece of junk. Want to get a SCSI. Does HDD performance bottleneck in demanding apps or games? Would it speed up Doom for example?
HDD: Looking at a Quantum 4GB SCSI
GRAPHICS CARD: ATI VGA Wonder card... It's alright but would a TSENG card make a big difference where CPU is lacking?
SOUND CARD: SB AWE64 card. I assume the offload from the CPU is minimal here

What should I be focusing on the most?

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Reply 1 of 41, by jesolo

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I presume that this is a follow up to your other thread (Problems with AM386DX-40 chip)?

I believe that this should be your motherboard (which is a Biostar): http://arvutimuuseum.ee/th99/m/A-B/30648.htm
Based on the schematics, it would appear that the vendor either produced the motherboard with the 66 MHz crystal (and then provided a 33 MHz 386 CPU with it) or the 80 MHz crystal (with a 40 MHz 386 CPU) - so, I think it's safe to assume that this motherboard will work with a 40 MHz CPU if you swop out the 66 MHz crystal with an 80 MHz one.

To touch briefly on the CPU:
Back in the early 90's Cyrix introduced the 486SLC & 486DLC CPU's which were meant as an upgrade path for existing 386 owners of 386SX & 386DX CPU's respectively.
The benefit of these CPU's is that it offered a 1 KB level 1 cache, which provided improved performance over an existing 386 CPU (provided that the motherboard was "compatible" and the L1 cache was enabled).
You can read up more about it here: https://en.wikipedia.org/wiki/Cyrix_Cx486DLC & here: https://www.philscomputerlab.com/cyrix-486dlc.html
Just take note of the challenges and potential pitfalls. There is no guarantee that, with your particular motherboard, a Cyrix 486DLC (or one of its clones from Texas Instruments) will work with your motherboard.
However, should you be able to install a Cyrix 486DLC (not SLC) 40 MHz on this motherboard (with the L1 cache enabled), then you can expect performance more or less on par with that of a 486SX 33 MHz.
Since the first PC that I bought for myself was a Cyrix 486DLC 40 MHz, I can confirm the above.

FPU:
Unless you are planning using this PC for heavy duty CAD programs or running spreadsheets (like Excel or Lotus 1-2-3), you won't see any performance boost in your other applications.
The only two games that I'm aware of that makes use of an FPU (and that will run satisfactory on a fast 386) is SimCity & Falcon 3.0.

RAM:
I think that 8 MB should be sufficient for a 386.
Bear in mind that, back in those days, memory cost a fortune and most people only had 4 MB of RAM on their 386 PC's (and, as such, games were tailored to make use of that).

Cache:
Based on the schematics, the motherboard either supports 64k or 256k of cache.
If you can find the right chips (and depending on what settings your BIOS has for memory timings), increasing the cache to 256k should yield slightly faster performance.

I/O (HDD) Controller:
I'm not very knowledgeable when it comes to SCSI since, back in the day, I couldn't afford it myself.
I went straight from IDE, to VLB and then to PCI and so on.
However, it is my understanding that SCSI does yield better transfer rates but, it can also sometimes be a challenge to get up and running.

HDD:
Just bear in mind that your BIOS most definitely will have a limit in terms of the maximum HDD size that it will support (which in this case is 528 MB or 504 MiB).
This is more of a problem if you are using an IDE based HDD. I'm not 100 % sure how this impacts SCSI devices (which I think ran independently from the motherboard BIOS).

Graphics card:
Back in the day the Tseng Labs ET4000AX was probably one the most famous graphics chipsets (in terms of speed) on your ISA bus as it outperformed your competition like Trident.
However, I believe that some Cirrus Logics cards (like you CL-GD5422 chipsets) performs just as well. Finding later models on an 16-bit ISA card might prove a bit problematic.
I'm not sure how the ATI VGA Wonder card would compare to the above but, it will probably also depend on the particular chipset (model) of your card.

Sound card:
The SB AWE64 is probably a bit too "modern" for this type of CPU (a Sound Blaster Pro or compatible card is probably better suited).
However, on this motherboard, it will "behave" just like a regular AWE32 (Wavesynth/Waveguide is not supported on anything slower than a Pentium 90 MHz).
The benefit is that this card does not suffer form the so called MIDI hanging note bug and you can also use it for General MIDI based games.
However, the AWE64 uses Creative's CQM synthesis to "simulate" a real Yamaha OPL3 chip. Some people are not too bothered with it, other people dislike it.

I think that your greatest speed improvements will come from upgrading your CPU to a Cyrix 486DLC (once again, be aware of the challenges and pitfalls) and your graphics card.
However, some of these upgrades can be very costly these days due to their rarity.
Despite the above, even on my 486DLC 40 MHz, Doom 1 still runs a bit slow but much better than on a 386DX 40 MHz (I would recommend at least a 486DX2 66 MHz for that with VESA Local Bus graphics).

Reply 2 of 41, by Gahhhrrrlic

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Thanks for the response!

I was hoping, as you said, that this board was sort of swappable between cpu speeds so I may attempt the 80 MHz crystal.

I've read about the Cyrix, especially the TI flavour which has more cache but I've been having trouble finding one to buy. Also I've heard there are some compatibility issues so before I get into that I may try the crystal swap first so I can see how 40MHz feels.

The FPU is more of a novelty and believe it or not I like ACAD and Excel... plus I like programming too so maybe this will help after all. I only hope it matches cpu speed or I'm screwed because I have the 40mhz flavour of that also.

I'm not too confident in my abilities to interpret memory and cache timings so until I learn more about that I may leave well enough alone.

I've heard about how scsi is difficult to set up but I still don't really know what that means. I know the cable has to be terminated but apparently some devices terminate themselves. I haven't figured out how to check if this quantum HDD can do that or not. Aside from that I'm not aware if I need drivers or not, merely that the controller has its own bios. I'm not sure to what extent most games retrieve game data on the fly but if it's significant, these SCSI drives apparently eliminate all the CPU work required for retrieval on top of being faster so maybe that would have a noticeable effect.

Actually this computer has repeatedly used 2GB hard drives just fine. Maybe it's because I had dos and win3.1??? I always put multiple partitions on the drive so whatever I've done in the past it somehow breaks the 500mb barrier since I can access all 2gb. Those were IDE.

I would like to try the TSENG card if it offloads work from the CPU. It's hard for me to really understand how graphics cards before the era of hardware acceleration actually did anything for the computer other than rasterize to the monitor. I don't really see how they provide any benefit in old games. But I will take the community's word for it.

The sound card is probably overkill. I have another crappy SB card somewhere I could use instead. I've heard some people get a roland card for midi. Do you install both cards and run separate drivers on each? How do they work together exactly? I guess most game setup programs do ask you for both a music card and a sound effects card. Maybe this is where you would choose the Roland and SB respectively?

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Reply 3 of 41, by feipoa

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I have this motherboard and also replaced the 66.666 Mhz oscillator with an 80 MHz oscillator. Does your board have 33 MHz printed on the chipsets? I was reading this on vogons wiki, http://www.vogonswiki.com/index.php/386_Chipsets

These early chipsets often have their top speeds stamped into the tops, and exceeding these limits can result in permanent damage as early VLSI chips were very sensitive.

My motherboard also has the 33 Mhz written on the chipset, but 40 MHz seems to work. The issue I had was I could not get anything above 64 KB of cache to work stable. How much cache is in your board?

Have you been to this post on 386 upgrade paths? 386 upgrade kits and the Transcomputer 486HPi - Am5x86-160 anyone?

If your board doesn't have a machine pin socket for the crystal oscillator, you should solder one in. Then you can swap the oscillator any time.

I use SCSI in my 386 systems. For bus mastering SCSI, the Adaptec 1540/1542. For non-bus mastering, 1520/1522 is common. I've used both. If you use the 1540 and a DLC/SXL CPU, you may need to set the BARB method to invalidate the L1 cache. This is setup with a DOS software driver. I have worked out most of the stable combinations for this board, so if you go with a Cyrix DLC or TI DLC, or TI SXL, I can help you with the quirky requirements needed for the L1 cache enabler.

As for graphics cards, Tridents of the 8900C series are slow, as are cards based on the Oak OTI077 chip. Basically, the better cards are all of similar DOS speeds, like the Tseng Labs ET4000AX, ET4000/w32i, Cirrus Logic GD5434, or Mach64. And when I say faster, I benched10.5 fps in Doom on the slower cards and about 14-15 fps on the faster ones.

Also, I would not really call the TI 486DLC a clone of the Cyrix 486DLC. TI is the one who manufactured the DLC for Cyrix and had permission to sell the chip under their own branding.

Plan your life wisely, you'll be dead before you know it.

Reply 4 of 41, by jesolo

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feipoa wrote:

Also, I would not really call the TI 486DLC a clone of the Cyrix 486DLC. TI is the one who manufactured the DLC for Cyrix and had permission to sell the chip under their own branding.

Agreed - in my haste I should probably have used the term "rebranded".

Reply 5 of 41, by Gahhhrrrlic

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Is a mach64 really comparable in performance to a TSENG? I have one of those laying around. I assumed the VGA wonder was faster than that already but of course I have not benched it yet.

I will check the chipset to see if it has the speed written on it. I have a feeling the warning may be related to thermal limits of the chip but most chips can take a boost of 10% or so without breaking a sweat. 20% is probably doable. There are always heatsinks...

If you know of a place where I can buy one of the Cyrix chips, I will look into it. I have this bizarre prejudice in my head that buying something with a 486 printed on the front is blasphemy for a 386 build. I know the internals are more 386 than 486 but still. Seems like cheating. Maybe I'll try the 40 MHz first and see how it fares.

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Reply 6 of 41, by Anonymous Coward

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TI 486DLC chips also seem to be far more common the Cyrix branded type.

I don't know that ET4000 is really much better than a VGAWonder (if it's a plus, XL or XL24). On an ISA bus, most of the later cards seemed equally slow to me. Even if the Tseng is slightly faster, the VGA Wonder can store settings in EEPROM, and has a great set of drivers and utilities, especially the monitor calibration. This was especially important in the days before monitors with digital controls. Just something to think about if you plan to use an older CRT.

Comparing an ET4000AX to a Mach64...I would almost certainly go with the Mach64. Have you seen the prices of those things lately? They can easily fetch $100.

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 7 of 41, by jesolo

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Gahhhrrrlic wrote:

If you know of a place where I can buy one of the Cyrix chips, I will look into it. I have this bizarre prejudice in my head that buying something with a 486 printed on the front is blasphemy for a 386 build. I know the internals are more 386 than 486 but still. Seems like cheating. Maybe I'll try the 40 MHz first and see how it fares.

Just search on eBay for "486DLC".
I've found a couple of them (some below $30).

Reply 8 of 41, by Samir

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Great thread! I'll add some tidbits of what I remember of this era.

The 486SLC/DLC chips were great for that they could do. Single biggest boost to a system for sure.

Moving to SCSI would be the second biggest boost for your system since it would relieve the cpu from all the disk transfer activities, the second biggest system activity besides memory transfers.

Video card upgrade would also help, especially with more processing done on the card.

Reply 9 of 41, by Gahhhrrrlic

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Seems fitting to resurrect this thread rather than start a new one since I have a follow-up question on RAM.

I pretty much can't find any sort of schematic or manual for this board... so I'm shopping blind, but what I want to do is install 16MB of the fastest ram I can find. I noticed that after 1MB simms there aren't really any 2mb simms, it skips to 4mb. So the first question is, can each slot hold as much as 4MB so that I can do 4 x 4 in 4 banks and the next question is can I leave the other 4 banks empty? Right now all banks are full of 1mb each so by doing 4x4 I may be exceeding the capacity for each slot as well as violating some rule that I have to fill all of them.

As for the ram itself, no clue what limits are on the specs, so right now I found some FPM ram, 30 pin, 60nS, 9 chips each, with parity. Half the modules I have now are 9 chip so I'm assuming that's ok but I don't know about the FPM or the parity being ok.

Feipoa, if you're listening, you said you have this board too? Any comments on RAM specs?

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Reply 10 of 41, by Anonymous Coward

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Most of the better 386 motherboards made before 1992 used something called "bank interleave" for the main memory. The optimal configurations for these boards is 8 SIMMs. However, as far as I can tell they will always work with 4 SIMMs with a small performance penalty. As far as I can tell, nearly all of the boards made after 1992 use 486 chipsets, and implement enhanced caching schemes to compensate for the lack of bank interleaving. These newer boards are normally faster, except when something has to be fetched directly from main memory.

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 11 of 41, by dionb

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Anonymous Coward wrote:

Most of the better 386 motherboards made before 1992 used something called "bank interleave" for the main memory. The optimal configurations for these boards is 8 SIMMs. However, as far as I can tell they will always work with 4 SIMMs with a small performance penalty. As far as I can tell, nearly all of the boards made after 1992 use 486 chipsets, and implement enhanced caching schemes to compensate for the lack of bank interleaving. These newer boards are normally faster, except when something has to be fetched directly from main memory.

Question is though how the cache in a DLC would affect that. I sort of suspect that it would reduce the advantage of better cache on the motherboard, favouring the ibterleaved mem access...

Reply 12 of 41, by feipoa

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Gahhhrrrlic wrote:

Feipoa, if you're listening, you said you have this board too? Any comments on RAM specs?

I'm not sure I understand the question. If you are using 64 KB of cache, then you shouldn't go above 16 MB of RAM. Four sticks of 9-chip FPM, 60 ns RAM should work just fine. You will have to test for yourself if 8 MB (8 sticks) has any tangeable benefit to 16 MB (4 sticks). I didn't take notes on this, but sorta recall not seeing any difference.

Plan your life wisely, you'll be dead before you know it.

Reply 13 of 41, by Gahhhrrrlic

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I would of course prefer to fill all banks but unless there's 2MB SIMMs out there, I would think the next step up from 8MB would be then 32MB, which I've heard is a bad idea... can't remember why but I think it may cause issues in certain software?

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Reply 14 of 41, by kixs

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You can also fill it with 4x1MB + 4x4MB = 20MB.

8MB is quite enough for 386, even for 486. Unless you want to run Windows 95. I only once used 32MB in 386 - why not 😉 But it's useless.

Requests are also possible... /msg kixs

Reply 15 of 41, by Samir

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feipoa wrote:
Gahhhrrrlic wrote:

Feipoa, if you're listening, you said you have this board too? Any comments on RAM specs?

You will have to test for yourself if 8 MB (8 sticks) has any tangeable benefit to 16 MB (4 sticks). I didn't take notes on this, but sorta recall not seeing any difference.

I remember doing these type of tests back in the day and it really depended on what operating system you were using. In DOS, having more memory meant a bigger cache through smartdrv. In win 3.1, it meant less swapping or that the smartdrv was able to cache your swapfile. If you were running large programs, 8 was nice to have and 16mb was a nice overkill since you could make an 8mb smartdrv and still have an 8mb swapfile. In win95, 8 and 16mb were night and day where 32mb was really the sweet spot if you were under 64mb of ram.

(I keep having to force myself to put 'mb' vs 'gb'--it's amazing how the ram sizes are an order of magnitude larger and computing itself hasn't gotten an order of magnitude faster.)

Reply 16 of 41, by Gahhhrrrlic

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Also I had a cool idea that I would make a RAM drive and run games from it, which would actually solve the other problem I have with my SCSI card being slow as shit (in my win95 machine, which I was going to swap into my 386). It still serves its purpose of offloading CPU overhead but being so slow, it's nice to have a RAM drive for those hdd-intensive games and what better way to do that than with excess super fast ram.

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Reply 17 of 41, by Samir

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Gahhhrrrlic wrote:

Also I had a cool idea that I would make a RAM drive and run games from it, which would actually solve the other problem I have with my SCSI card being slow as shit (in my win95 machine, which I was going to swap into my 386). It still serves its purpose of offloading CPU overhead but being so slow, it's nice to have a RAM drive for those hdd-intensive games and what better way to do that than with excess super fast ram.

Ramdrive was always awesome. Ram was so unaffordable back then, but today you can easily have a 64mb ramdrive and get some killer speed. Kinda like the trick of copying a cd to the hard drive to make installs or running a game faster.

Reply 18 of 41, by vetz

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Regarding storage, SCSI is only faster if you have a period correct drive. If you go with IDE and a newer storage solution that will be quicker, as well as easier. The problem with SCSI controllers is that they reach their internal bottleneck before the ISA bus limit.

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Reply 19 of 41, by Samir

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vetz wrote:

Regarding storage, SCSI is only faster if you have a period correct drive. If you go with IDE and a newer storage solution that will be quicker, as well as easier. The problem with SCSI controllers is that they reach their internal bottleneck before the ISA bus limit.

SCSI was quirky in terms of drivers and compatibility with the various devices before ASPI, but it was almost always a slow drive to blame if the drivers and software were correct. I never saw any IDE system back in the day that could touch a properly set up SCSI system in terms of CPU usage--it was that much of a difference.

And I think you may have the bottleneck backwards as Fast SCSI could transfer 10MB/sec while the ISA bus maxed out at 8MB/sec. If anything, the SCSI drive would have to wait on the bus and cpu.