victormun wrote on 2023-11-24, 10:27:

This sums up to 1.5Gb of max RAM.

In theory. Not all combinations will be supported, plus there's the cache size and configuration (as well as particular chipset type) that might limit the amount of usable RAM.

As for DIMMs, keep in mind there are single and multi-rank modules. Chipset might not be capable of working with newer, higher capacity RAM chips - and only recognizes part of the available memory. Frankly I have been using 128MB and 256MB sticks on Socket7 mobos as 32 or 64MB because it's easier for me to find cheap 128MB 133MHz sticks than 32 or 64MB ones rated for 66 or 100MHz. As long as it works and passes memtest I'm happy.

512MB sticks were a problem for Athlon/Duron mobos, I remember that trying to upgrade RAM in these systems near the end of their useful life was a bit of a lottery. I don't have much experience with Slot1 mobos but I would assume these had similar issues.

Thanks for your insights!

I've been digging a bit more and have found that the Apollo Pro133 Chipset can only read a maximum of 128Mb per DIMM. I guess that kinda answers this question.

Sorry for double-posting but there is a question that comes to my mind: if 128mb is the actual max limit of this chipset... How come that the board manual talks about 256+ DIMM configurations? And what is more: it states that the maximum RAM is 1.5gb. This would be impossible to achieve if 128mb per DIMM is the limit.

It should work at least with dual-rank 256 Mb modules, i.e. 16 chips, excluding ECC.

Did you know that high density 256MB modules are not supported on this one?

What you need is low density 256MB modules for the 440BX chipset.

256MB low density is 16 chips total per module.

Cheers,

dionb goes into detail in this post: Computer only detects half the RAM

I hadn't realized that there was this limitation of the Apollo Pro 133 chipset, but realistically that's a Windows 9x platform so you can easily have well more than enough RAM.

VIA VT82C693A (Apollo Pro 133) is a poor choice for PIII due to its abysmal memory performance. It is partially fixable by wpcredit chipset register editor in Windows, but I would still highly recommend getting a 440BX board.