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First post, by mzry

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Hi all,

I'm struggling to get RAM that is recognized fully by the motherboard. I understand it needs to be half density, but I'm struggling to find these details on eBay. Also the CUBX supports ECC, so ideally I'd really like 1GB of memory in ECC.

Can anyone point me in the right direction?
(located in the UK but can import if needed)

Much appreciated,

Cheers

Reply 1 of 6, by TrashPanda

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440bx doesn’t officially support 1gb of ram, 256mb modules are the highest density size supported.

So grab two 256mb pc 100 modules in ECC or non ECC.

If you are running XP or NT them you can go to three modules with little issue.

I say officially but I have yet to find a BX board that could run 1gb of ram.

Reply 2 of 6, by dionb

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half density

This sort of vague term has always done more harm than good....

A source should specifiy *which* density, rather than calling it "half" or "low" or indeed "high" or "double" or whatever - as what was "high" density in 1998 (when the i440BX came out) was "low" or "half" density by 2000 (when the CUBX was released) 😮

i440BX can support max 128Mb chips. That is the only correct statement about density. A regular unbuffered SDRAM DIMM can hold max 16 of those chips in a dual rank configuration. 16x128Mb=256MB.

So, you need 256MB DIMMs with 16 chips, and the chips need to be of the 16Mx8 (not 32Mx4, frequently marketed as 'Via only', not JEDEC compliant and usualy only from shady vendors). Find four identical 256MB DIMMs with 16 chips each from a reputable brand (Micron, Infineon, Nanya, Samsung, TwinMOS, Hynix etc) and you should be good to go.

Reply 3 of 6, by mzry

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dionb wrote on 2022-09-26, 18:46:
This sort of vague term has always done more harm than good.... […]
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half density

This sort of vague term has always done more harm than good....

A source should specifiy *which* density, rather than calling it "half" or "low" or indeed "high" or "double" or whatever - as what was "high" density in 1998 (when the i440BX came out) was "low" or "half" density by 2000 (when the CUBX was released) 😮

i440BX can support max 128Mb chips. That is the only correct statement about density. A regular unbuffered SDRAM DIMM can hold max 16 of those chips in a dual rank configuration. 16x128Mb=256MB.

So, you need 256MB DIMMs with 16 chips, and the chips need to be of the 16Mx8 (not 32Mx4, frequently marketed as 'Via only', not JEDEC compliant and usualy only from shady vendors). Find four identical 256MB DIMMs with 16 chips each from a reputable brand (Micron, Infineon, Nanya, Samsung, TwinMOS, Hynix etc) and you should be good to go.

Thanks for the info. Do you know why the following didn't work for me? The ram chips are named: k4s280432b which according to the datasheet is: 128Mbit SDRAM 8M x 4Bit x 4 Banks, but I don't know if the datasheet is correct for the ram sticks in question. The two extra 2x chips, one for each side is parity right? Being ECC and all.

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Reply 4 of 6, by TrashPanda

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Double sided sticks don’t play nice with 440BX, try to stick with single sided sticks.

The sticks above are they registered ECC ?

Registered ECC won’t work in many desktop boards unless they specifically support it.

The extra chips are likely parity and buffer if they are buffered ECC.

I’m on mobile sorry if my replies seem brief.

Reply 5 of 6, by pentiumspeed

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These sticks are registered ECC modules. Not compatible with BX chipset, which requires unbuffered SDRAM modules.

Cheers,

Great Northern aka Canada.

Reply 6 of 6, by dionb

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TrashPanda wrote on 2022-09-26, 19:17:

Double sided sticks don’t play nice with 440BX, try to stick with single sided sticks.

Eh? Only the 32M/16Mx4 DIMMs won't work on BX, and despite having chips on both sides, they are 'single sided' as in only 64b / single rank wide.

Some motherboards have limitation on how the DIMM slots are wired up, with the last two slots usually sharing lines so you can do two single sided DIMMs or one double-sided in either, but that's not unique to BX and not the case on the CUBX in any event.

The sticks above are they registered ECC ? […]
Show full quote

The sticks above are they registered ECC ?

Registered ECC won’t work in many desktop boards unless they specifically support it.

The extra chips are likely parity and buffer if they are buffered ECC.

I’m on mobile sorry if my replies seem brief.

Exactly, these aren't unbuffered DIMMs so won't work on this board. ECC isn't a problem, registered/buffered is.

You want 256MB DIMMs with 16 (or 18 if going for ECC) chips of the same size, no extra register/buffer chips.