This is not the point.
The point is the other posters are saying is, needs low density DIMMs for BX chipset. Anything more than 128MB per 8 chips is not supported, beyond that is considered high density.
In other word, you can have: 128MB DIMM with 8 chips that is on one side, or 256MB with 16 chips total (that covers both sides of DIMM) is supported for BX. You need to be careful buying and insist on checking auction pictures of same 256MB stick to see that both sides of chips are present. Micron, Hynix, Samsung, Infineon and Crucial are good brands. PC100 or PC133 are fine, but on BX, will run at PC100, no problem.
Expect to pay little more. Never from Chinese seller.
Example:
https://www.ebay.ca/itm/164858713327?hash=ite … EsAAOSw~g1gmUqU
Cheers,
Great Northern aka Canada.