one more question - which models/brands of crystal oscillators for overklocking of a 386-CPU over 40 MHz (maybe 45-50 MHz) are recommended?

I took a look at page 1 of this thread and followed the links for some 386-systems, but could not find any info.

Never seen 386 cpus packaged like that. Are they functional ?

As for your second question - all crystals work as advertised, except in one instance of extreme overclock.
What are you after ? : )

pshipkov wrote on 2024-04-12, 04:45:

Never seen 386 cpus packaged like that. Are they functional ?

As for your second question - all crystals work as advertised, except in one instance of extreme overclock.
What are you after ? : )

The CPUs are still not tested, as I am affraid, they are maybe not 386 (with risk to damage my mainboards).
Maybe I should try them anyway (as I have a very corroded 386-board here still booting/posting - no matter if it goes even more damaged by those IBM-chips, or not)

About the crystals - I would be thankful to know, which models do you (or other people here) recommend for overclockng a "standard" AMD 386DX-40 to 45/50 MHz (if lucky).

Thereafter I can have a look where to buy them (at this time I do not have any crystals for overclocking above 40 MHz).

Next update: both IBM-CPUs are 386!
Tested with a FIC-386SC, Rev. A3. Both work at 33 MHz, no one work at 40 MHz. Identified by CheckCPU as "standard 386"; identified by Speedsys as 80386DX (not sure about the correctness of this, maybe they are DX, or maybe SX).
In generally, they seems to be "nothing special".
Another test with a FIC-386-HC-HG, Rev. B, was not able to start both IBMs. Sadly, after that, no one more boot with every other 386-CPU is possible on this board (the IBMs still boot on the 386SC, so maybe the HC-HG has another problem).

Next thing is: few hours ago somebody brought me a desoldered IBM-chip in more or less bad condition, no idea is it working or not. Fortunately, all pins are present.
Is this maybe an IBM Blue Lightning BL2-BL3? Can the original frequency be recognized by the imprint?

Here Creating a voltage regulated 386 BL3 module from existing parts and here Re: 3 (+3 more) retro battle stations they are shown similar chips.
Compared to an adapter PGA-132 to QFP-132 with AMD-386DX-40, this IBM-chip is smaller, so it maybe can not be soldered instead of the AMD-CPU on the same adapter. And, of course, the number of the pins is different.
Are they other (smaller) adapters ecpecially for this IBM-chip on the market?

gonzo wrote on 2024-04-12, 17:50:

Next update: both IBM-CPUs are 386! Tested with a FIC-386SC, Rev. A3. Both work at 33 MHz, no one work at 40 MHz. Identified by […]
Show full quote

Next update: both IBM-CPUs are 386!
Tested with a FIC-386SC, Rev. A3. Both work at 33 MHz, no one work at 40 MHz. Identified by CheckCPU as "standard 386"; identified by Speedsys as 80386DX (not sure about the correctness of this, maybe they are DX, or maybe SX).
In generally, they seems to be "nothing special".
Another test with a FIC-386-HC-HG, Rev. B, was not able to start both IBMs. Sadly, after that, no one more boot with every other 386-CPU is possible on this board (the IBMs still boot on the 386SC, so maybe the HC-HG has another problem).

Next thing is: few hours ago somebody brought me a desoldered IBM-chip in more or less bad condition, no idea is it working or not. Fortunately, all pins are present.
Is this maybe an IBM Blue Lightning BL2-BL3? Can the original frequency be recognized by the imprint?

Here Creating a voltage regulated 386 BL3 module from existing parts and here Re: 3 (+3 more) retro battle stations they are shown similar chips.
Compared to an adapter PGA-132 to QFP-132 with AMD-386DX-40, this IBM-chip is smaller, so it maybe can not be soldered instead of the AMD-CPU on the same adapter. And, of course, the number of the pins is different.
Are they other (smaller) adapters ecpecially for this IBM-chip on the market?

Yes, the online search confirmed these are some early 386DX models.
Your tests confirm they don't scale very well, which i kind of expected.

---

There are 386 DX and SX variants. I am not going to bring the well know details about them here - you can check online - plenty of info on the subject.
DX variant has 132 pins.
SX variant has 100 pins.

Later on improved processor models came to market as upgrades to the standard 386SX/DX CPUs.
DLC -> DX
SLC -> SX
The processors you show are SLC variants - pin incompatible with DX/DLC.

For them you can try motherboards like Alaris Leopard, or Matra 486SLC2.

deleted (double post)

deleted (double post)

pshipkov wrote on 2024-04-12, 18:52:

DX variant has 132 pins. SX variant has 100 pins. The processors you show are SLC variants - pin incompatible with DX/DLC.

That explains a lot for me, thank you.

About the crystal oscillators for overklocking of a 386-CPU: I just found some info for one of your systems here Re: 3 (+3 more) retro battle stations, it is a crystal from ecliptek shown in the picture. If you know other manufacturers, please let me know, thanks.

Forgot to confirm your question about crystal oscillators.
Ebay is littered by them. Brands dont matter. Search for “crystal oscillator”. Can include additional keywords like “dip14” or “full can”.
Depends on how far you anticipate to go, consider buying a clock generator. They are more expensive, but even few crystal oscillators will build up to the same sum of $, wile leaving you with far fewer options.

pshipkov wrote on 2024-04-13, 08:15:

Forgot to confirm your question about crystal oscillators.
Ebay is littered by them. Brands dont matter. Search for “crystal oscillator”. Can include additional keywords like “dip14” or “full can”.
Depends on how far you anticipate to go, consider buying a clock generator. They are more expensive, but even few crystal oscillators will build up to the same sum of $, wile leaving you with far fewer options.

Thanks. Is the correct voltage 5 Volt?

Yes.

gonzo wrote on 2024-04-11, 15:48:

Are these two chips maybe 386-CPUs from IBM?
Should I risk to open/take-down the aluminium covers of them without damage of the cores?

Sadly I can not give any additional infos about them, as they are from "a friend of a friend of a friend"...

Did somebody crack open a few ps/2s to get these? I’m surprised they worked at 40mhz

I didn't see frequencies associated with these CPUs, but i assume they are early/slow models, still reaching 40MHz, at least getting lights on screen, is doable for even 25MHz rated silicon. Do you know more about them ?

Anonymous Coward wrote on 2024-04-15, 03:08:

I’m surprised they worked at 40mhz

No, they did not - only 33 MHz.
See my posting above "Both work at 33 MHz, no one work at 40 MHz"

pshipkov wrote on 2024-04-15, 19:12:

Do you know more about them ?

I don't know too much, except that CPU collectors like them. As far as I know they were only manufactured by IBM and only used in their own hardware. Functionally they should be the same as their intel counterparts.

Comparison of ISA SCSI / IDE / EIDE controllers

--- Premise
This area have not been sufficiently "researched" on a big enough scale, especially considering baseline / maximum performance, and stability.
Occasionally, I come across pieces of information here and across the broader Internet. However, it's evident that these insights are often subjective due to the scarcity of comprehensive data. I've decided to conduct a more thorough investigation, gather sufficient information, and attempt to minimize the subjectivity.

--- Context

During the 386 era, ISA local starge controllers reached their zenith. However, they were superseded by VLB and PCI devices in 486 systems and beyond.
This initial post will concentrate on the 386 scenario, but findings from peak 286 overclocking experiments will be shared subsequently (more on that below).

--- Approach

1. Evaluate a wide range of IDE and SCSI controllers of different types.
2. Collect information from three 386 + one 286 test scenarios. Select the right hardware components accordingly - motherboards, processors, ...
3. Conduct well-known and relatable tests, presenting only these for improved readability while carrying out more detailed testing behind the scenes.

Few more notes:

Over 40 different ISA controllers of different brands/models have been tested.
Intention is to cover the range between years 1990 and 1996, even 1997.
Few more cards will be added soon. After that "tactical" updates may occur from time to time.

The 4 test scenarios:
DTK PEM-4036Y is the smoothest, clock-to-clock fastest 386 motherboard.
Scenario 1: 386DX processor at 40MHz, 40MHz base frequency, 10MHz ISA bus frequency, 16Mb RAM, 256Kb L2 cache. As described here.
Scenario 2: IBM BL3 processors at 100MHz (2x50), 50MHz base frequency, 25MHz ISA bus frequency, 16Mb RAM, 256Kb L2 cache. As described here.
MSI MS-3124 is clock-to-clock slower than DTK PEM-4036Y. Problematic with some DLC processors. The highest watermark of 386 performance.
Scenario 3: IBM BL3 processors at 110MHz (2x55), 55MHz base frequency, 27.5MHz ISA bus frequency, 16Mb RAM, 256Kb L2 cache. As described here.
Dunson Electronics 286-16 is the fastest, most scalable 286 motherboard.
Scenario 4: Intersil 286 processor at 30MHz, 30MHz base freqiency, 30MHz ISA bus, 2Mb RAM, 0 wait states. As described here.

--- Constraints

Testing was conducted exclusively in DOS 6.22, while a few additional intriguing controllers were evaluated in Windows 3.11. However, the results in Windows 3.11 did not differ significantly from those obtained in DOS. Only CF cards were utilized, with no mechanical HDDs involved. Mechanical HDDs introduce a greater degree of unpredictability. By using CF cards, this variability is reduced, allowing the focus to shift almost entirely to the performance of the controllers themselves.

ZuluSCSI and Acard adapters were used to connect CF cards to SCSI controllers. Acard adapters offer greater compatibility because some controllers search for a boot device only at ID 0, whereas ZuluSCSI is permanently set to ID 1. However, ZuluSCSI performs better under conditions of peak overclocking.

Caching controllers were tested with maxed-out RAM.

--- Controllers

Unknown (SiS 83C66)
Works well under normal conditions.
Technically works at 27.5MHz, subtle flakyness. Write-access and auto-progression issues.
Passes the 25MHz test. Write-access issue.

Unknown TK-82C869/865 2J D01 (UMC UM82C863F, UMC82C865F)
Numerous controllers featuring this (or early) UMC chipset were produced across various brands and models.
Touched quite a few of them.
The pictured one represents them all.
Standard controllers. Do not handle overclocking. Function fine under normal conditions.

Unknown TK-82C869/865 2J D01 (PiC P4020, P4021)
One of the best IDE controllers out there.
Scales really well on overclock. It can even handle 0 DRAM wait states with the MSI motherboard - crazy.
Write-access issues under extreme overclock.

Unknown SMART-A2-B (Mobic MS62C452, WDC WD37C65CJM)
Technically passes all tests.
Write-access and auto-progression issues at 27.5MHz.
Write-access issue at 25MHz.

Unknown (Acer M5105 A4E)
Works well up to 25MHz. Write-access issues in this test.
Nothing more to say really.

Unknown (FDC37C65B)
Technically works in all tests.
Write-access and auto-progression issues under extreme overclock.


Unknown (MX 9028G, NCL NCL2020-50)
Standard controller. Nothing special about it.
Fails the 27.5MHz test.
Passes the 25MHz one with the usual write-access issue with CF cards.

Acculogic sIDE-4/HP
Scales very well.
Technically functional in the 27.5MHz test, but exhibits the write-access and auto-progression issues.
Works well at 25MHz. Write-access issue.

Unknown RT-1206-B
Standard controller.
Does not handle overclocking.
Works fine in standard conditions.

Acculogic sIDE-4
Standard controller.
Does not handle well overclocked ISA bus.
Functional in the baseline 10MHz test.

Acculogic sIDE-3/Plus
Standard controller. Nothing specifically to say about it.
Fails the 27.5MHz test.
Passes the 25MHz one with the usual write-access issue with CF cards.

Promise EIDE Pro (LGS Prime 3B)
Write-access and auto-progression issues in the 27.5MHz test.
Fastest IDE in the 25MHz test. Write-access issues.
One of the best controllers overall, especially considering its other qualities.

DTK PTI-227 (Windbond W83757F)
Many controllers featuring this, or early version of the chip, have been produced. Evaluated 5 or 6 of them. They typically function well under normal conditions, but this is the only model that scales well on overclock, despite the occurance of write-access issues. This particular controller ranks among the best available.

Chicony CH-101B REV.1.0
Middle of the pack controller.
Passes the 25MHz test with write-access issues.
Works well under normal conditions.

Promise SuperIDE
Slow assembly.
Fails the 27.5MHz test, passes the 25MHz one without write-access issues because of the low performance.
Works well under normal conditions, but slow.

Promise DC-2031
Slow assembly.
Fails the 27.5MHz test. Works up to 25MHz. No write-access issue since its performance is below the threshold where they start occuring.

Longshine LCS-6641
Unstable in the 27.5MHz.
Does well up to 25MHz. Because of its relatively low performance it manages to avoid the write-access issue.

Unknown Prime 2C MKIII
Numerous controllers featuring the Prime 2C chip were produced across various brands and models.
Touched quite a few of them.
The pictured one represents them all.
Standard controllers. Do not handle overclocking. Function fine under normal conditions.

Tekram DC-800B
Can hang during BOOT with IBM BL3 L1 cache enabled.
DOS5 support must be enabled, or fails to BOOT from the attached local storage device, but can from FDD. Strange.
Handles overclocking well - passes all tests, but somehow it is difficult to setup in the 10MHz session.
DMA speeds cannot exceed 6.67Mb/s for 27.5MHz and 8Mb/s for 25MHz.

Adaptec AHA-1510/20/22B (1520, 1522)
A non bus-mastering controller. Can coexist with IBM BL3 L1 cache. A big plus.
Scales really well.
Unfortunaly it exhibits the auto-progression issue at 27.5MHz.
Best performer in the 25MHz test along with AHA-1530P.
While AHA-1530P can technically funcion in 10Mb/s DMA speed, this controller cannot go past 6.67Mb/s.
Somewhat slow in the 10MHz test.

Adaptec AHA-1540/42CS100
Requires Acard adapter to see the bootable device at ID 0.
IBM BL3 L1 cache issues.
Fails the 27.5MHz test.
Passes the 25MHz one.
Overall slow and flaky device.

DTC 3280AS
Does not work with ZuluSCSI, needs Acard for bootable device at ID 0.
Fails the 27.5MHz test.
Technically works at 25MHz, but flaky.
Works fine under normal conditions.

SIIG XL-221 (SCSI Pro)
Does not handle the overclock tests. Works well in the baseline 10MHz one.

Adaptec AHA-1540/42CF and AHA-1540/42CP
Integrated RAM eliminates the need of ROM SHADOWING - a plus.
Fails to recognize local storage device in the 27.5MHz test.
IBM BL3 L1 cache issues.

Adaptec AHA-1540/42B
Not tested yet. Soon.

Bustek BT-542B and Buslogic BT-542B
Needs Acard adapter to see bootable device at ID 0.
If ROM SHADOWING is enabled it can hang during POST or BOOT.
BIOS version 3.36b needed or can hang with CF cards.
Hangs with DMA TEST FAIL error during POST in the 27.5MHz test.
Technically passes the 25MHz test but can hang if IBM BL3 L1 cache is enabled.
Works well under normal conditions and standard 386 processors.
Slow.

Trantor T160
Technically sees CF card, but never stable enough for proper testing.
Am i missing something here ?

Adaptec AHA-1530/32P
A non bus-mastering controller. Allows it to coexist with IBM BL3 L1 cache. A big plus.
Scales really well.
Unfortunaly it exhibits the auto-progression issue at 27.5MHz.
Technically it can do it 10Mb/s DMA speed. In this case perf is impressive - over 6.6Mb/s.
Best performer in the 25MHz test.
Somewhat slow in the 10MHz test.

Advansys ABP-5140/42
Technically, this is the best ISA controller compared to all others. Impressive performance. Very nice BIOS menu. Fast initialization. Unfortunatelly it does not play nice with IBM BL3 processors when their level 1 cache is enabled.

Future Domain TMC-1680
Was not able to make this controller recognize CF cards. Anyone ?

SIIG i540/542
One of the fastest controllers out there - number one in the 10MHz test.
Very nice BIOS menu - same as Advansys ABP-5140/42.
Unfortunatelly does not scale well - fails the 25MHz and 27.5MHz tests.

Buslogic BT-545S
Can hang during BOOT with IBM BL3 L1 cache enabled.
Hangs with DMA TEST FAIL error during POST in the 27.5MHz test.
Works well at 25MHz and lower.

Adaptec AVA-1505/1515
Requires Acard adapter to see bootable device at ID 0.
Fails the 27.5MHz test.
Passes the 25MHz one.
Slow.

Promise DC-2040
This controller went silent early on. Shows some "cache fail" during POST.
Needs further investigation.

Procom ISA SCSI Xelerator
Impressive assembly. Includes RAM which eliminates the need for ROM SHADOWING.
Very nice BIOS - highly automated, descriptive.
Clearly a high-end device in its time.
Fails the 27.5MHz test.
Works up to 25MHz. IBM BL3 L1 cache related issues - can hang the system.

Always IN-2000
Does not see CF cards.
Am i missing something here ?

Acculogic ISApport
The controller appears dysfunctional. At least i cannot get it to see CF cards.
Anyone ?

Adaptec AHA-1535A/AI
Not tested yet. Soon.

Adaptec AHA-1520/22A
Not tested yet. Soon.

Adaptec AHA-1540/42C
Not tested yet. Soon.

Future Domain TMC-1610m
Does not handle overclocking well - stops recognizing local storage device, hangs, etc.
Works well in the 386 baseline test. Above average performer.
Requires Acard adapter to see the bootable device at ID 0.

Holtek LCMSIO-2A
Not tested yet. Soon.

Unknown CCAT200A (SMC37C75L J P)
Not tested yet. Soon.

--- Results and conclusions

Gray bars indicate not fully system.

The label "BL3 L1" points to problems associated with the IBM BL3 processor when its level 1 cache is enabled. This issue specifically affects SCSI controllers. It's particularly regrettable since some of these controllers perform exceptionally well under peak overclocking conditions.

The label "WA" denotes write-access issues, which are observed in all IDE controllers when subjected to extreme overclocking. This problem is exclusive to CF cards. Occasionally, the controller might not complete a write operation to the local storage device, prompting a user dialog that offers options to "abort" or "retry." Selecting "retry" typically resolves the issue.

The label "flaky" signifies difficulties in configuring the controller to a functional state. However, once these initial setup issues are resolved, the controller operates effectively.

386 extreme overclocking scenario 1: MSI MS-3124, IBM BL3 110MHz (2x55), 55MHz base frequency, ISA bus at 27.5mhz, 16Mb RAM, 256Kb level 2 cache.
In this test, all controllers encounter issues. The Advansys ABP-5140/42 would have been the standout performer if not for compatibility problems with the BL3's L1 cache. The Adaptec AHA-1520B and AHA-1530P were close to passing, but they occasionally disrupt the keyboard controller, leading to automatic progressions or erratic behaviors in some tests, games, and applications, similar to when certain keys are held down on the keyboard.
The PiC P4020/4021-based card emerges as the top IDE controller, offering exceptional speed and stability. However, it's not without its flaws, notably the occasional write-access issue that can arise with CF cards.

386 extreme overclocking scenario 2: DTK PEM-4030Y, IBM BL3 100MHz (2x50), 50MHz base frequency, ISA bus at 25mhz, 16Mb RAM, 256Kb level 2 cache.
2.5MHz less and the list of survivors grows significantly.
Big number of IDE controllers and almost the same number of SCSI ones.
The non us-mastering AHA-1530P and 1520B are the clear winners.


386 standard use case scenario, DTK PEM-4030Y, AMD 386DX 40MHz, 40MHz base frequency, ISA bus at 10mhz, 16Mb RAM, 256Kb level 2 cache.
As expected, all controllers worked in this test, with 2-3 exceptions.
SCSI dominates the field.
SIIG i540/542 and Advansys ABP-5140/42 are the clear winners - way ahead of everybody else.
In fact the performance they show does not fit my world view of what 10MHz ISA bus can do.
Yet, running concrete tests, like copying bulk of files, confirms the performance is real. Hey, i will take it.
No write-access issues with IDE controllers. This problem appears above the 3700Kb/s mark.


286 extreme overclocking scenario: Dunson Electronics 286-16, Intersil 30MHz, 30MHz base frequency, 30MHz ISA bus, 2Mb RAM, 0 wait states.
Placeholder for upcoming update.
It will be a very compact chart, similar to 386 at 27.5MHz, but even shorter.

--- Summary

IDE offers better scalability and reliability with CPU upgrades. The performance of IDE improves with higher overclocking levels. Cards based on the PiC P4020/4021 are the top choices available.

Under typical conditions, such as minimal or no overclocking and compatible CPU upgrades, SCSI is the preferred choice. The top-performing cards are SIIG i540/542, Advansys ABP-5140/42, Adaptec AHA-1530P, AHA-1520B.
The Adaptec cards with their non-bus-mastering design ensures compatibility with IBM BL3 processors.
Also, they perform very well when overclocked.

It is worth nothing that while IDE controllers are more or less plug and play, the SCSI ones require more time to setup properly. Often small details get in the way, which adds friction.

--- Feedback welcome

Do you recognize brands/models in the listed controllers ?

If you spot inconsistencies, or lack of clarity - please let me know.

Did you succeed to make Always IN-2000 and Trantor T160 work with CF cards ?

>The label "BL3 L1" points to problems associated with the IBM BL3 processor when its level 1 cache is enabled.

You got L1 problems at high FSB but not on 10MHz? That doesnt sound right for L1 compatibility issue.

The 10MHz ISA bus test is with 386DX processor.
I described the 4 test scenarios at the beginning of the post, but will repeat them right on top of every chart, so the context does not get lost.

Sorry for missing it. Does the BL3 system also have problems with floppies? in Re: 3 (+3 more) retro battle stations you reported system 1 FDD working. Weird to have working fdd but still L1 problems with Adaptecs. Would it be fair to say the problem is not SCSI adapters, but system not compatible with CPUs with L1 cache?

Some comments:

Unfortunately, there are way too many variants of the DTI PTI-227. Finding your exact card will be difficult. When I tried my PTI-227 card (looks different than yours) on my DTK PEM-4030Y, I got missing characters on the screen.

Those write access comments have me concerned about potential corrupt files in Windows. I'd feel more comfortable running the ISA bus at 25 MHz or less to avoid this.

The performance from those caching controllers is really disappointing.

I didn't know that if a HDD controller card has some onboard RAM that shadowing isn't required. Is this the case for nearly all IDE and SCSI host controllers that have onboard RAM, presumably SRAM? Have you run into any issue leaving ROM shadowing enabled if the host controller also has this onboard RAM?

How many different keyboard controller types did you test in attempt to resolve the issue with the AHA-1520/1530B at 27.5 MHz?

Too bad about the Advansys ABP-5140/5142 not working with BL3 chips. How many motherboards did you try it on to conclude this? Sometimes some motherboards have issues with BL3 L1, while others don't. Did the Advansys controller work with SXL2 chips?

I am blown away by the benchmark results for the SIIG i540. I think most users won't be going much above 13 MHz for their ISA bus, so this card would be the clear winner. Did you test it with an SXL2, DLC, or BL3 CPU? How high can you clock it reliably?