It depends. Sometimes you have to use so called "low density" ram sticks. For example older chipsets (BX) doesn't support 512 MB sticks at all, and regarding 256MB ones you have to choose carefully (those with more chips works better).

For newer chipsets (i845, KT133, etc.) I would choose the smallest possible number of memory sticks.

BTW. In fact, dual channel mode appeared in the days of DDR memory, except maybe ALI Aladdin 7 chipset (SDRAM socket 7).
So there is no performance gain.

My board supports the 512 ram sticks. So its better to stick to this one? Anything i should be aware?

1) yes
2) no

😀

atom1kk wrote on 2022-09-07, 12:58:

My board supports the 512 ram sticks. So its better to stick to this one? Anything i should be aware?

You should be aware that even though the board is reporting the 512mb stick correctly it will only ever use half of the stick as the BX memory controller doesnt support the number of ICs on a 512mb stick.

I have a Asus P2B-D 1.06 (440BX) and it too reports all PC133 512mb sticks correctly but refuses to actually use the full stick in tests, once it hits the limits of the memory controller it starts throwing memory errors for the 256mb of memory it cant actually access.

For 440BX its better to stick with 256mb sticks to retain full compatibility with the 440BX memory controller.

I have the VIA 694X Chipset (VIa 133A)

zyga64 wrote on 2022-09-07, 12:34:

BTW. In fact, dual channel mode appeared in the days of DDR memory

this! On SDR motherboards all DIMM sockets are in parallel. Thats because CPUs of the time were single core with narrow instruction decoders and very low instruction level parallelism (https://en.wikipedia.org/wiki/Instruction-level_parallelism), they didnt know how to utilize more BW.

atom1kk wrote on 2022-09-07, 12:07:

Hi, I know since DDR RAM it is mostly better to run the RAM in dual channel mode, it means to have to equal RAM sticks. But how is it with SD? I have know 2 x 128 MB. and I want tu upgrade to 512. so is it better to buy 2 x 256 or 1 x 512? I want to stick to 512 as a max, since it is enough for me and do not get in any issues with win98

It depends on the board (or more specifically, the chipset).
If it's a BX then you'll need 2x256MB PC-100 (or PC-133 which can downclock, I'd recommend just getting PC-133 if you can) with 8 memory chips on both sides of the module.
256MB sticks with 8 memory chips in total will have only half the memory recognized at best.

Personally I find 256MB (with 16 chips total, 8 each side) PC-133 the most compatible memory modules whilst retaining large memory size (still won't fully work with 430VX, same problem only part will be recognized but imho this is but a relatively minor issue since smaller SDRAMs are abundant). 512MB (and 256MB with 8 or 9 chips max) have fewer motherboards that are fully compatible with it.

I'll use a single stick if it fits my agenda, there's few reasons to use more but smaller sticks of memory except perhaps if you have an excess of the smaller stick sizes.

In cases of mixing memory (especially if you have a large amounts of varying different memory modules from multiple sources) I prefer to at least use SDRAMs using identical memory density (so for instance I'd mix a 256MB module with 16 chips with a 128MB module with 8 memory chips, preferably using chips of the same manufacturer or at least as similar to each other as possible.
Some older boards can be a bit ehh....temperamental when it comes to installing memory modules 😋

Serverworks has a few dual sdr-sdram chipset offerings. It provides the exact same bandwith of DDR-Sdram.

ALI, VIA and SIS had DDR chipsets for the PIII as well, offering equal bandwith. But the PIII, even the Tualatins, do not profit hugely from the doubled width. A well configured 694X can offer great performance, but your mileage will vary more than when you use a i815e based mainboard or even the overclocked 440BX.
If you like things out of the ordinary, have a look at i820 or i840 based Rdram boards. No extra performance safe for the bragging rights of owning a contemporary stupidly expensive system.

Im pretty happy with my via board since it has an isa slot and adjustable fsb. This is mostly what i need. So i can use the p3 800 with a gf2 for bit newer games and the plan is to get a Voodoo 1 and underclock than tje cpu for early 3dfx games. I just wanted to max out my ram for win98 and want to know if there might be some issues or what i have to look for.

The ram i have an offer for is a 512 apacer pc133 cl3 stick with 16 chips on it.

If it's a 694, I can safely say you can stick a 512MB in there. I have had two Infineon branded sticks (plus a random 256 I had on hand to fill the third slot) run ~1.2GB worth of SDRAM on a Epox 3VCM running Server 2003.

IIRC the limit on 694 was 1.5GB (or 2Gb, I don't really remember but it was around these values) worth of SDRAM so unless you have 3x512MB you probably won't be close to hitting that limit.