AFAIK they do exist, but hard to find. You're not loosing much with 256Kb though.

Your module is asynchronous as there are 8x 8bit SRAM chips + 8bit tag. 512kB also do exist. However, it might be actually faster to run your system without any L2 cache as async cache comes with a big write penalty on 430FX. See my https://dependency-injection.com/intel-430fx- … riton-l2-cache/ article about this.

Pipelined burst modules are much better. They have large two large PBSRAM chips + one small SRAM chip. The 512k is very similar except it has chips on both side. You want a module that looks like this one:

mpe wrote on 2020-09-11, 09:37:

Your module is asynchronous as there are 8x 8bit SRAM chips + 8bit tag. 512kB also do exist. However, it might be actually faster to run your system without any L2 cache as async cache comes with a big write penalty on 430FX. See my https://dependency-injection.com/intel-430fx- … riton-l2-cache/ article about this.

Pipelined burst modules are much better. They have large two large PBSRAM chips + one small SRAM chip. The 512k is very similar except it has chips on both side. You want a module that looks like this one:

DSC_7945.jpeg

Thank you for this. I found an HP module for a decent price and just bought it.

It is an HP 0960-0944, hopefully it works!

So here's something weird. The machine will not POST with the module plugged in. I will try to clean the contacts, but either the module is dead or the machine is not compatible with it. Has anyone ever encountered this issue?

My guess is that it is not compatible.

Took me a bit to find a 512Kb module for my dual socket 7 ASUS board and I had to order it from overseas and it wasn't cheap.

You need to find out exactly what is compatible with your motherboard and then find one.

I might have one that would work as I have quite a few I have gotten in different scrap lots.

You don't really need 512Kb module, it's not worth the hassle of finding it: Intel 430HX L2 256Kb VS Intel 430HX L2 512Kb VS Intel 430TX L2 512Kb - Motherboards comparison

My guess is that it is not compatible.

COAST modules are universal, so this one is probably dead.

The Serpent Rider wrote on 2020-09-17, 21:12:

You don't really need 512Kb module, it's not worth the hassle of finding it: Intel 430HX L2 256Kb VS Intel 430HX L2 512Kb VS Intel 430TX L2 512Kb - Motherboards comparison

My guess is that it is not compatible.

COAST modules are universal, so this one is probably dead.

My memory is vague on this, but weren't there proprietary motherboard/cache sticks that were not actually COAST compatible but looked like they might be (same or similar edge connector, but different pinout) ?

AST-AUTISMO wrote on 2020-09-17, 18:25:

So here's something weird. The machine will not POST with the module plugged in. I will try to clean the contacts, but either the module is dead or the machine is not compatible with it. Has anyone ever encountered this issue?

Yes. And it was the one that came with the machine!

cyclone3d wrote on 2020-09-17, 18:41:

My guess is that it is not compatible. […]
Show full quote

My guess is that it is not compatible.

Took me a bit to find a 512Kb module for my dual socket 7 ASUS board and I had to order it from overseas and it wasn't cheap.

You need to find out exactly what is compatible with your motherboard and then find one.

I might have one that would work as I have quite a few I have gotten in different scrap lots.

Any chance you can post a photo of the modules in your collection as well as the one you have confirmed as working?

The Serpent Rider wrote on 2020-09-17, 21:12:

You don't really need 512Kb module, it's not worth the hassle of finding it: Intel 430HX L2 256Kb VS Intel 430HX L2 512Kb VS Intel 430TX L2 512Kb - Motherboards comparison

My guess is that it is not compatible.

COAST modules are universal, so this one is probably dead.

The manual for my ASUS board only lists a single one verified working AND has some that they specifically say won't work.
Snip from the manual:

According to an Intel motherboard datasheet (advanced EV) looks like these are the characteristics the 430 boards are compatible with.. but are newer modules supposed to be backwards compatible?

· Supports 3.3 volt mixed mode (5.0 volt power, 3.3 volt signal) or level-triggered modules that adhere to the
COAST specification version 1.2
· Supports 256 KB or 512 KB asynchronous or Pipelined Burst cache in write-back mode
· Single sectored cache for 256 KB and 512 KB for optimal performance
· Data SRAM speed is 15ns which supports up to 66 MHz processor (external) bus speed.
· 3-1-1-1 reads and writes at all processor speeds when using Pipelined Burst cache
· 3-2-2-2 reads and 4-3-3-3 writes with Asynchronous cache

hwh wrote on 2020-09-17, 21:41:

AST-AUTISMO wrote on 2020-09-17, 18:25:

So here's something weird. The machine will not POST with the module plugged in. I will try to clean the contacts, but either the module is dead or the machine is not compatible with it. Has anyone ever encountered this issue?

Yes. And it was the one that came with the machine!

So was your module dead?

Are we sure that later modules are backwards compatible? The board is a 430fx in LPX form factor, manufactured by intel and customized for AMD, so i don't think weird COAST modules (like that asus or that one weird pc-chips board) are a concern. I've seen some labeled 1995, 1996, 1997, different IC manufacturers and layout.

Also, are the notch heights on either side of the modules in any way significant? The one that came out of my machine has a very low nootch height, just above the connector. The non-working one i bought has much higher notches

AST-AUTISMO wrote on 2020-09-18, 02:25:

hwh wrote on 2020-09-17, 21:41:

AST-AUTISMO wrote on 2020-09-17, 18:25:

So here's something weird. The machine will not POST with the module plugged in. I will try to clean the contacts, but either the module is dead or the machine is not compatible with it. Has anyone ever encountered this issue?

Yes. And it was the one that came with the machine!

So was your module dead?

I don't know. I haven't had the occasion to try it elsewhere.

I have an Advanced/EV. It works without the cache. I was able to put in a different one, and I don't know if it works, but the system certainly does...

AST-AUTISMO Can you post a picture of the motherboard?

If it is made by Intel I bet it would be compatible with COAST specification rather than any proprietary deviation using the same connector.

I have a number of COAST modules in my collection. Such as:

Out of these, the top 2 are non-standard. I actually destroyed a motherboard by putting the second one to a non-compatible mb as it is a non-pipelined synchronous burst using a very different pinout than all the other.

The remaining ones are adhering to COAST spec (different versions) and they are compatible with almost all 430FX, 430HX, 430VX, SiS 5511, UMC4489 and Opti motherboard I tested them in.

But since you board originally came with async. module, perhaps it doesn't have the necessary clock drivers for PBSRAM chips? Are there any jumpers on the motherboard? Many boards need to be switched between async/pb sync cache modes if they have both options.

Just wanted to say, that only thing standard was the physical connector, not even the pinout.

As far understand the connector is CELP (card edge low profile) and it has been indeed used in different non-compatible implementation.

The pinout itself should, at least on 430FX/HX motherboards, be covered by the COAST (cache on the stick) specification. But there are several revisions and each of them also has multiple implementation options. Presumably depending on if the module is designed to replace or extend the cache that's already on the motherboard, handling of tag SRAM (for 430HX motherboards), size options, etc.

If anyone has a copy of any version of these COAST specifications, please share them!

mpe wrote on 2020-09-18, 08:28:

AST-AUTISMO Can you post a picture of the motherboard? […]
Show full quote

AST-AUTISMO Can you post a picture of the motherboard?

If it is made by Intel I bet it would be compatible with COAST specification rather than any proprietary deviation using the same connector.

I have a number of COAST modules in my collection. Such as:

DSC_7983 (1).jpeg

Out of these, the top 2 are non-standard. I actually destroyed a motherboard by putting the second one to a non-compatible mb as it is a non-pipelined synchronous burst using a very different pinout than all the other.

The remaining ones are adhering to COAST spec (different versions) and they are compatible with almost all 430FX, 430HX, 430VX, SiS 5511, UMC4489 and Opti motherboard I tested them in.

But since you board originally came with async. module, perhaps it doesn't have the necessary clock drivers for PBSRAM chips? Are there any jumpers on the motherboard? Many boards need to be switched between async/pb sync cache modes if they have both options.

Here are a couple board photos. It'a out of an AST Advantage machine. Advantage 6xx/8xx have the same board. Apparently this is a very close variant to the one used on some Packard Bell machines. (pb640, pb660)

Is there any way to tell if PB is supported?

Jumper settings:
Function Jumper Position
� Bus speed select 1/4 clock speed J4K1 pins 2 & 3
closed
Bus speed select 1/3 clock speed J4K1 pins 1 & 2
closed
� Setup access enabled J4K1 pins 4 & 5
closed
Setup access disabled J4K1 pins 5 & 6
closed
� CMOS memory normal operation J5K2 pins 1 & 2
closed
CMOS memory clear J5K2 pins 2 & 3
closed
� Password enabled J5K2 pins 4 & 5
closed
Password disabled J5K2 pins 5 & 6
closed
� Factory configured - do not J9K1 N/A
alter

Top left, Dell cache module asnyc. Top right, Apple cache module.

Cheers,

Well well well. Rather interesting development.

I got another COAST module from amibay at a fairly high cost. Seller tested the module on a 430fx board prior to shipment, so known good, and theoretically known compatible. Well, it wouldn't boot.

I dunno how it came to me. I was looking at the contacts and it occurred to me that something may be wrong with the connector. I played around with the module when the machine was off. I tried plugging in the module to just after the fingers grab and no further. Lo and behold, the module works.

I tested and there is a definite performance gain vs the async module and it is confirmed to be PB by a DOS utility (so not a case of the module not plugged in enough so the machine boots as if there were nothing there.)

So then I take the original HP module that did not work and tried the same trick. It also worked. However, when i tried seating the module a little deeper in the slot (bottoming out) the computer NEVER boots. The weird thing is, the ASYNC module it came with WILL work when bottomed out completely, but neither of the PB modules will.

So now I am happily running the HP COAST module since it matches the mobo color and will throw the new COAST module on ebay.

CONCLUSION:
If your board won't boot with a PB COAST module installed, back it out of the slot a bit. In my case I see about a half millimeter of the pins when looking at the module from the the side. It is deep enough to be retained securely, but also work.

Bonus:
Small performance bump as expected. From 31 to 36fps in Quake and from 24 to 29 FPS on DN3D rooftop in 640. As the article posted above states, I measured a drop in mem bandwidth with the ASYNC module vs either no or the PB module. But oddly the ASYNC was still faster in games vs no module at all.