the 440bx officially supports:
100fsb
sdram density up to 16mb per chip(so each dimm size is limited to 256mb with 16 chips, and 128mb with 8 chips)
1gb total ram size(only in 4 dimms with 16 chips each)

and since you are using a 512mb dimm, no doubt you are going out of spec and its very likely to go wrong, although the outcome is not predictable for me.

nwsw wrote on 2020-08-02, 12:37:

@dionb, thanks for the input. Here's my exact RAM purchase:
https://www.ebay.com/itm/153188692778

As for the why, I shouldn't have to explain that on this site. (Because I can!) 😀

Er, except on this chipset: you can't 😜

i440BX has more than earned its legendary reputation, but it remains a 1998 chipset with limitations that prevent it using 2001-era DIMMs fully. Slightly dubious ad btw, no mention of DIMM or chip vendor and exact chip codes you're getting. Fortunately that's usually not a problem with BX though.

Have you tried loosening timings and upping VDIMM yet?

noshutdown wrote on 2020-08-02, 15:18:

the 440bx officially supports: 100fsb sdram density up to 16mb per chip(so each dimm size is limited to 256mb with 16 chips, and […]
Show full quote

the 440bx officially supports:
100fsb
sdram density up to 16mb per chip(so each dimm size is limited to 256mb with 16 chips, and 128mb with 8 chips)
1gb total ram size(only in 4 dimms with 16 chips each)

and since you are using a 512mb dimm, no doubt you are going out of spec and its very likely to go wrong, although the outcome is not predictable for me.

Regarding the too-big DIMMs it's perfectly predictable as explained in the link darry posted:
https://web.archive.org/web/20180103032407/ht … ram_bx_faq.html

If you go over 128Mb per chip, only the first 128Mb will be used, and 16x128Mb=256MB.

It's been a long time since I read Intel's specs on the 440BX, but from what I remember it only specifies up to 4 "rows" of unbuffered memory. The limit goes up to 8 "rows" if the memory is registered. I'm calling them "rows" because that's the terminology that appears in Award BIOS POST screens.
A double sided 256MB module with 16-18 (16Mx8) RAM ICs on it is 2 rows. These are the largest modules that can be used by the 440BX.

If you stick to Intel's guidelines, the max memory is 2x256MB unbuffered = 512MB total of unbuffered memory at 100MHz FSB.
If you use registered memory, you can go up to 4x256MB = 1GB registered.
It's so easy to break the 440BX's official limits that it becomes easy to forget what the limits are supposed to be.

My experience (mostly Asus boards, but I've had some other brands of 4-DIMM boards I might have tried it on also) has been that you can go up to a full 1GB of unbuffered memory if you stay at 100MHz. If you overclock to 133MHz, that's when pushing the unbuffered memory limit gets questionable.

Several years ago I had several Asus P2B-F and P3B-F boards. I cherrypicked 2 of them (both were P2B-Fs) and sold off the rest. Both of those boards ran long term with 4x 256MB unbuffered memory at PC133 CL2 timings with overclocked P3s at 800/133FSB and an AGP card at 89MHz. Both setups were initially stress tested at 140MHz FSB and still passed Prime95/Memtest86 like that.
Breaking a lot of rules, but their 133FSB stability was excellent, *except* for the bootup. That was the one hitch - I had trouble getting them to POST the full amount of memory.
Whenever I booted the machine it would report some random amount of memory in the range from 600MB-1GB. I'd have to hit reset once or twice until it showed the full 1GB at POST. Once it did that, I'd let it continue booting and it was perfectly stable in actual operation. It was just the bootup that was temperamental.

Thanks all! I have tried messing with the timings and VDIMM. Since I don't have registered memory, I'll just stick with the 1GB at 100mhz. It's plenty powerful for what I need. (Late 90s/Early 2000s)

BX chipset supports up to 256MB per module (16 chips), typically either 2 or 3 dimm slots. 8 chip 256MB modules and 512MB per modules are not supported on BX chipset. 815 chipset is moot and is limited to 512MB max total.

You need to order OEM brands like Micron, Hynix, Samsung, Elpida, and buy 256MB with 16 chips modules, PC100 or PC133, and windows 98 will only support 512MB and don't exceed that for stability.

combinations:
128MB x 2 and 256MB x 1 for 512MB or 256MB x 2 for 512MB.

Cheers,

Hi All,
I wanted to give an update on my progress. Thanks for the feedback and the support from the wiki, it's been helpful.

I ended up finding an Asus P3V4X complete in box, so I went ahead and replaced the Abit BX-6. I'm now rocking my PIII 933mhz at proper 133mhz FSB along with 1.5 GB SD133 RAM. (512, 512, 256, 256). I know that's lot of sticks, but I've run it through the various tests and it's working absolutely fine.

I've got one SD card for Windows 98 and one for Windows XP. The only trick that I found is it only has 1 ISA slot, so I can't use my ISA SB16 and ISA HardMPU-401 cards at the same time. I'm just going to use an external USB sound card for now and keep the HardMPU-401 installed so I can use General MIDI with my SC-55.

I'm now happily playing Morrwind and Asheron's Call at proper framerates and the PC can run everything from 386 up to Morrowind with a few simple BIOS switches and a swap of the SD Card. 😀

How are you limiting the visible ram to windows 98se so only see 512MB? Critical to stability and switches used when launching windows 98se not allowed.

Cheers,

if I use larger chips on the 440bx some software will detect the full capacity but the memory controller will never use it (uses half), just trust whatever the board on bootup reads AFAIK.

pentiumspeed wrote on 2020-08-19, 00:23:

How are you limiting the visible ram to windows 98se so only see 512MB? Critical to stability and switches used when launching windows 98se not allowed.

Cheers,

I'm using PATCHMEM. (RIP RLoew).

This is one of these that can break the compatibility and stability issues using this?

Cheers,

pentiumspeed wrote on 2020-08-19, 04:50:

This is one of these that can break the compatibility and stability issues using this?

Cheers,

Is that a question or a comment? If it's a question, personally I haven't experienced any instability issues.

nwsw wrote on 2020-08-18, 21:41:

I've got one SD card for Windows 98 and one for Windows XP. The only trick that I found is it only has 1 ISA slot, so I can't use my ISA SB16 and ISA HardMPU-401 cards at the same time. I'm just going to use an external USB sound card for now and keep the HardMPU-401 installed so I can use General MIDI with my SC-55.

This suggests you aren't using DOS, so wouldn't it be easier to just use a PCI card suitable for Win98 such as a Sound Blaster Live?

Oetker wrote on 2020-08-19, 06:16:

nwsw wrote on 2020-08-18, 21:41:

I've got one SD card for Windows 98 and one for Windows XP. The only trick that I found is it only has 1 ISA slot, so I can't use my ISA SB16 and ISA HardMPU-401 cards at the same time. I'm just going to use an external USB sound card for now and keep the HardMPU-401 installed so I can use General MIDI with my SC-55.

This suggests you aren't using DOS, so wouldn't it be easier to just use a PCI card suitable for Win98 such as a Sound Blaster Live?

I'll pick one up once I head to RE-PC but for now it works and I can play most DOS games through Windows 98. I can pick up stacks of PCI/ISA sound cards there on the dollar, so might as well save money.

I was playing Betrayal of Krondor and Doom earlier in Windows 98 and I was able to use the USB sound card for sound effects and the HardMPU for General MIDI. No issues.

FYI, mods can probably close this thread at this point since I have replaced the motherboard and it has the necessary info.

Cannot close. Vogons is very vital knowledge so these is kept open as related replies get added to this.

Cheers,

Warlord wrote on 2020-08-02, 07:05:

very few very late 440bx boards had proper AGP/PCI dividers. So if your board doesn't have that, or you don't bother to set it […]
Show full quote

very few very late 440bx boards had proper AGP/PCI dividers. So if your board doesn't have that, or you don't bother to set it correctly you are effectively overclocking the AGP and PCI bus by running the memory at 133 mhz. poor stability is one thing. Frying expansion cards is another, or frying your board because the cards fry. It's not that 440bx cannot handle 133 mhz, its that majority of the boards don't have dividers, like you see on good Pentium 4 boards.

You need to take into account also the more sticks of ram you slot the more stress that is putting on the VRM.
Like as if most 440bx actually have what in modern times is considered a VRM.
Add a power hungry GPU a fe expansion cards and decide to run your fans off the motherboard headers, it's a recipe for disaster.

I know I'm replying to a 2020 post but... Can it actually fry a card ?
I'm running at 120MHz AGP (Evil Kyro II, board is EP-BX7+100). It works but I had no idea it can fry it. To me the risk was just that the card can't communicate properly with the system.
The card isn't overclocked most of the time, sometimes by 10% or so but that's it. AGP voltage is stock.

JustJulião wrote on 2022-11-04, 09:56:

I know I'm replying to a 2020 post but... Can it actually fry a card ? I'm running at 120MHz AGP (Evil Kyro II, board is EP-BX […]
Show full quote

Warlord wrote on 2020-08-02, 07:05:

very few very late 440bx boards had proper AGP/PCI dividers. So if your board doesn't have that, or you don't bother to set it […]
Show full quote

very few very late 440bx boards had proper AGP/PCI dividers. So if your board doesn't have that, or you don't bother to set it correctly you are effectively overclocking the AGP and PCI bus by running the memory at 133 mhz. poor stability is one thing. Frying expansion cards is another, or frying your board because the cards fry. It's not that 440bx cannot handle 133 mhz, its that majority of the boards don't have dividers, like you see on good Pentium 4 boards.

You need to take into account also the more sticks of ram you slot the more stress that is putting on the VRM.
Like as if most 440bx actually have what in modern times is considered a VRM.
Add a power hungry GPU a fe expansion cards and decide to run your fans off the motherboard headers, it's a recipe for disaster.

I know I'm replying to a 2020 post but... Can it actually fry a card ?
I'm running at 120MHz AGP (Evil Kyro II, board is EP-BX7+100). It works but I had no idea it can fry it. To me the risk was just that the card can't communicate properly with the system.
The card isn't overclocked most of the time, sometimes by 10% or so but that's it. AGP voltage is stock.

AGP cards no, they can run at 66Mhz just fine and many will tolerate even higher speeds, PCI cards running out of spec will generally cause a lot of stability issues but that does depend on the card itself. Some PCI cards are designed to run on a 66Mhz PCI bus and so an out of spec 33Mhz PCI bus doesn't cause them issues but early PCI cards and cheap poorly designed/built ones will very likely crash the PC and possibly can damage the card but that is exceedingly rare. Damaging the motherboard is also highly unlikely as the stability issues will restart the PC before any damage might occur.

Still if you can avoid running the PCI/ISA buses out of spec with BIOS switches then its recommended to do so, exceeding 100 FSB is also not recommended but some late model BX boards can handle and have the right switches to keep the AGP/PCI bus in spec. Its always best to do testing when setting up the PC to determine if your board is fine when running out of spec, your Kryo II card is a great card so having its AGP out of spec is fine and its not worth fiddling with it if its running stable.

Long thread. Short on time.

Usually if a mobo will only count to 768 it means that max supported memory is 512mb. Or that you installed memory that is too dense. Being a PII mobo, I suspect that you installed memory that is too dense. Try loading it up with double sided 128 or double sided 256 sticks. Don’t stop at one type, try several different chip types.

TrashPanda wrote on 2022-11-04, 12:28:

JustJulião wrote on 2022-11-04, 09:56:

I know I'm replying to a 2020 post but... Can it actually fry a card ? I'm running at 120MHz AGP (Evil Kyro II, board is EP-BX […]
Show full quote

Warlord wrote on 2020-08-02, 07:05:

very few very late 440bx boards had proper AGP/PCI dividers. So if your board doesn't have that, or you don't bother to set it […]
Show full quote

very few very late 440bx boards had proper AGP/PCI dividers. So if your board doesn't have that, or you don't bother to set it correctly you are effectively overclocking the AGP and PCI bus by running the memory at 133 mhz. poor stability is one thing. Frying expansion cards is another, or frying your board because the cards fry. It's not that 440bx cannot handle 133 mhz, its that majority of the boards don't have dividers, like you see on good Pentium 4 boards.

You need to take into account also the more sticks of ram you slot the more stress that is putting on the VRM.
Like as if most 440bx actually have what in modern times is considered a VRM.
Add a power hungry GPU a fe expansion cards and decide to run your fans off the motherboard headers, it's a recipe for disaster.

I know I'm replying to a 2020 post but... Can it actually fry a card ?
I'm running at 120MHz AGP (Evil Kyro II, board is EP-BX7+100). It works but I had no idea it can fry it. To me the risk was just that the card can't communicate properly with the system.
The card isn't overclocked most of the time, sometimes by 10% or so but that's it. AGP voltage is stock.

AGP cards no, they can run at 66Mhz just fine and many will tolerate even higher speeds, PCI cards running out of spec will generally cause a lot of stability issues but that does depend on the card itself. Some PCI cards are designed to run on a 66Mhz PCI bus and so an out of spec 33Mhz PCI bus doesn't cause them issues but early PCI cards and cheap poorly designed/built ones will very likely crash the PC and possibly can damage the card but that is exceedingly rare. Damaging the motherboard is also highly unlikely as the stability issues will restart the PC before any damage might occur.

Still if you can avoid running the PCI/ISA buses out of spec with BIOS switches then its recommended to do so, exceeding 100 FSB is also not recommended but some late model BX boards can handle and have the right switches to keep the AGP/PCI bus in spec. Its always best to do testing when setting up the PC to determine if your board is fine when running out of spec, your Kryo II card is a great card so having its AGP out of spec is fine and its not worth fiddling with it if its running stable.

Interestingly, the Hercules version can't handle more than 115MHz on AGP, while the Evil Kyro does (both are Kyro II of course). So yes it seems that build quality matters big time !
This is a 180MHz FSB, that's why the AGP is @120MHz.
I anticipated the PCI issues so I'm using a late PCI-X SCSI controller for storage and a very late and well designed audio card (Auzentech Pelude 7.1, the idea was also to unload the Tua's tasks as much as possible).
I'm glad to read that it should not damage it. For now I have no stability issues, the only problem I still have is RAM, the only sticks I could find to handle that FSB speed are newer single sided ones (I did accordingly to Voodooman's testings about SD-RAM OCing) but it only sees 512mb on four slots. It should be fine for Kyro II's era games anyways.

JustJulião wrote on 2022-11-04, 16:17:

Interestingly, the Hercules version can't handle more than 115MHz on AGP, while the Evil Kyro does (both are Kyro II of course). […]
Show full quote

TrashPanda wrote on 2022-11-04, 12:28:

JustJulião wrote on 2022-11-04, 09:56:

I know I'm replying to a 2020 post but... Can it actually fry a card ?
I'm running at 120MHz AGP (Evil Kyro II, board is EP-BX7+100). It works but I had no idea it can fry it. To me the risk was just that the card can't communicate properly with the system.
The card isn't overclocked most of the time, sometimes by 10% or so but that's it. AGP voltage is stock.

AGP cards no, they can run at 66Mhz just fine and many will tolerate even higher speeds, PCI cards running out of spec will generally cause a lot of stability issues but that does depend on the card itself. Some PCI cards are designed to run on a 66Mhz PCI bus and so an out of spec 33Mhz PCI bus doesn't cause them issues but early PCI cards and cheap poorly designed/built ones will very likely crash the PC and possibly can damage the card but that is exceedingly rare. Damaging the motherboard is also highly unlikely as the stability issues will restart the PC before any damage might occur.

Still if you can avoid running the PCI/ISA buses out of spec with BIOS switches then its recommended to do so, exceeding 100 FSB is also not recommended but some late model BX boards can handle and have the right switches to keep the AGP/PCI bus in spec. Its always best to do testing when setting up the PC to determine if your board is fine when running out of spec, your Kryo II card is a great card so having its AGP out of spec is fine and its not worth fiddling with it if its running stable.

Interestingly, the Hercules version can't handle more than 115MHz on AGP, while the Evil Kyro does (both are Kyro II of course). So yes it seems that build quality matters big time !
This is a 180MHz FSB, that's why the AGP is @120MHz.
I anticipated the PCI issues so I'm using a late PCI-X SCSI controller for storage and a very late and well designed audio card (Auzentech Pelude 7.1, the idea was also to unload the Tua's tasks as much as possible).
I'm glad to read that it should not damage it. For now I have no stability issues, the only problem I still have is RAM, the only sticks I could find to handle that FSB speed are newer single sided ones (I did accordingly to Voodooman's testings about SD-RAM OCing) but it only sees 512mb on four slots. It should be fine for Kyro II's era games anyways.

Ram on BX can be an interesting case of musical dimms till you find ones that are both compatible with the BX chipset and can run stable at the speed you want, but thats part of playing with retro gear and for me its one of the fun parts.