It really depends on what the memory controller/chipset can use. Some boards won't take 512MB DIMMs, early ones might not like 256MB DIMMs. Chip density is a factor as well. RAM is not interleaved so using 1 2 or 3 DIMMs won't make any difference in speeds.

If you want an amount under 512MB but over 256MB, you sort of gravitate towards 384MB. You can do that with 3x 128MB or 1x 256MB and 1x 128MB. It shouldn't really make much difference in terms of performance. If you want to overclock significantly, keeping the memory bus load down can help, so use single-sided DIMMs. If not, just go for CL2 stuff and keep it at stock.

However for more specific info, as stated above you need to tell us which chipset you're using, and what FSB your CPU uses.

dionb wrote:

If you want an amount under 512MB but over 256MB, you sort of gravitate towards 384MB. You can do that with 3x 128MB or 1x 256MB and 1x 128MB. It shouldn't really make much difference in terms of performance. If you want to overclock significantly, keeping the memory bus load down can help, so use single-sided DIMMs. If not, just go for CL2 stuff and keep it at stock.

However for more specific info, as stated above you need to tell us which chipset you're using, and what FSB your CPU uses.

intel 440bx chipset motherboards will be asus p2b-vm/asus p2b/ga-6bxc rev 1.7 i will be going for 133mhz fsb so the cpus i will be using all support it. lets just focus on the p2b-vm(im sure i will be able to do the others once i figure this one out). i just took out 2 256mb pc100 sticks when i achieved 105mhz fsb, was going to try some 133 sticks but some say 133u and some 133 some dont say anything.. 🤣
is there a program i could use to display ram stick specs?

dionb wrote:

If you want an amount under 512MB but over 256MB, you sort of gravitate towards 384MB. You can do that with 3x 128MB or 1x 256MB and 1x 128MB. It shouldn't really make much difference in terms of performance. If you want to overclock significantly, keeping the memory bus load down can help, so use single-sided DIMMs. If not, just go for CL2 stuff and keep it at stock.

However for more specific info, as stated above you need to tell us which chipset you're using, and what FSB your CPU uses.

i meant 512 or under 256 or over sorry should of stated more clearly. but good to know ty

Arbys Guy wrote:

But, i would simply like to know with these 3 DIMM or even 2 DIMM slot boards, whats better using 3 sticks , 2, or 1? im happy with any amount under 512 but over 256MB

i have alot of ram so i should be able to do what ever you guys throw at me.

There is no simple answer for this, but there are definitely some rules of thumb that you can use.

First thing is to basically always firstly check which modules are supported and in which configurations. This is usually in the manual, though the manual may exclude some of the relevant information.
Slot 1 has several different chipsets which can follow different rules.

BX is a popular one as it's very stable and not as finnicky as a lot of the other chipsets from that era.
I'm pretty sure that by now you know the BX basic limitations, so I'll get to it now.

What I always tend to do, is first decide what I want the modules to run at (100MHz cl2 or 66MHz cl3 or whatever you want), then go through my stash of memory modules to see what I have matching up or is close to what I want.
I prefer to use modules which are similar, so same chip density, chips from the same manufacturer (preferably identical memory modules if I happen to have some). With BX I'd often end up with something like 1*128MB (16 chips, 8 on each side) and 2*64MB (8 chips, 8 on one side) as this is a nice way to make use of some of the smaller modules I have laying around.

Usually putting the maximum amount of memory and run this at the maximum available frequency, may result in instability.

But generally speaking, iirc it had to do with how many banks of memory you run on a board and at what speed (in mhz and in cas latencies). The fewer memory banks and the lower speed the memory is run at, the higher your chances are that this won't cause any stability issues.

Mixing all kinds of different memory modules together (say putting a 32MB (16 chips), then 256MB (8 chips) and then 128MB (16 chips)) may increase your chances of stability issues, so I try to prevent doing this since I have loads of memory modules to pick from anyway and I'm in a way a perfectionist.

Phil used over 256MB RAM and these days there isn't much reason to go with less anyway, but I have run a Celeron 400 with 192MB RAM and WinME just fine basically.
So suppose you have 2 memory slots. Seek out 2*128MB modules PC-133 with 8 chips each side, since you mention wanting to go to 133MHz FSB. Use identical modules or as close as you can find them, preferably of the same manufacturer.

But of course you can also just grab a single stick of 256MB PC-133 that is compatible with your chipset, leave all other slots empty and be done with it 😜

Most times I just grab whatever sticks and put them into whatever memory slots. Avoid silly things like mixing tiny memory sticks with big ones, PC66 memory on a PC133 board.

Set memory timings reasonably fast, CL2 and such. 9 out of 10 times, it will work great like that. I then test with memtest to make sure it is stable.

Updating motherboard BIOS can often help with memory compatability as well, so don't forget to do that.

thanks for the responses, very useful information! i updated the bios to the latest for the asus p2b-vm and ga-6bxc, been trying different fsb configs with the p2b-vm, cant get 133mhz working stable with 2 Infineon 128,sync,133,cl3 sticks(identical/double sided 8 on each side) would ram or cpu prevent 133mhz even if they are rated for it? or would this be the motherboard(gonna try and find supported ram)

diddnt have as much memory as i thought only really have matching doubles pc133, alot of matching 66/100 though. might have to take some more computers apart 🤣 think i have a few more untouched.

btw is cl2 better than 3?(whats the diff?) not sure what the SYNC or chip density means either or to find out if it has it.
also would i be changing the memory timing in bios? or are you talking about what outcome i get from different sticks, i can see the timings in cpu z

and lastly when the computer boots the memory test keeps restarting over and over with all the ram i have tried so far any reason for this? when i hit escape it runs just fine after.

CL2 ram is better than CL3. Often CL3 ram will run fine at CL2 speeds, sometimes not. Not a major performance difference.

Running your memory at 100mhz on a 133mhz system isn't the end of the world. Certainly not like the difference between say a Geforce 4 TI and Geforce 4 MX. Would be barely noticeable.

canthearu wrote:

CL2 ram is better than CL3. Often CL3 ram will run fine at CL2 speeds, sometimes not. Not a major performance difference.

Running your memory at 100mhz on a 133mhz system isn't the end of the world. Certainly not like the difference between say a Geforce 4 TI and Geforce 4 MX. Would be barely noticeable.

ha ha nice! i wouldn't know much about those cards i have a few MX cards i assume they are the worse ones because good things don't come in bundles 🤣 (at least for me so far!) i think i got a really good find 486 era in a tower loaded with cards!only 10$ looks like its for gaming(my knowledge of this era is crap but i think ill stick to 1 task at a time 🤣).
but i did find some more pc133 ram! 1 512mb133 to i think this might be the ticket if it works.
3 same brand/labels/size but 1 has a slightly taller board and different labeled chips infineon/malaysia XR-DIMM168/128SD-133 no cl marking,i tried them first it says this in cpu z with a 112fsb

so they are at cl 3 how would i get them to 2?
also is everything on the memory page better if its a lower number, well besides frequency.

Edit, when using the two sticks with the same chips(malaysia) i got this outcome! and passed the memory test at boot,

i also got the same result when adding some random infeon 256/133/cl2 stick in there. but failed the memory test(loop glitch)

not sure which one i want to go with now )=, do you think the memory test loop matters? maybe i should just stick with the 2 128 mb sticks ive heard 256mb vs 512mb wont boost windows 98 games and ms dos supported games.
i quickly just tried the 512mb card, it is posting the same and passing the memory test

LMAO.. so i guess the memory test passes after a few times... either way ..which setup would you guys recommend?

CL2 would be one of the memory settings in the BIOS (CAS to RAS timing typically) Should find it in CHIPSET SETTINGS or similarly named page.

You should also carefully check for leaking/damaged capacitors. These can create stability problems on these older motherboards ... If they are bulging or leaking, that means they need replacement.

I have at least half a dozen Geforce 4 MX cards ... they are like cockroaches and come with half of everything I get. Most are the really terrible MX-SE varients, with awful memory/core performance. The higher end non-SE variants are actually not all that bad, as long as you are not asking for more than DX7 from them.

i have been checking for bad caps but everything seems fine, ive only come across a few boards with leaking caps, mainly dells lmao, and 1 with a two number digital counter i kept, for a learning how to soldering project in the future., btw edited my earlier post i wasn't fast enough for ya! and ill stay away from those mx cards unless there is nothing else or worse 🤣.
btw i didn't change anything in the bios to achieve those results is there anything else you would recommend i do in the bios regarding memory? and which sticks to use. thank you again! seriously i would be so many steps behind if it wasn't for the awesome help on this site and phils computer lab videos!!!

Arbys Guy wrote:

intel 440bx chipset motherboards will be asus p2b-vm/asus p2b/ga-6bxc rev 1.7 i will be going for 133mhz fsb so the cpus i will be using all support it. lets just focus on the p2b-vm(im sure i will be able to do the others once i figure this one out)

Going for 133MHz on BX is overclocking, both the chipset and the AGP port and possibly the PCI bus too. General rule when pushing the limits is keeping it simple. The P2B-VM has onboard PCI VGA. Assuming it has a 1/4 PCI divider that shouldn't theoretically cause issues, but in practice it adds an extra point of failure. I hit something similar with my MSI MS-6168 rev.2.0 with Voodoo3 onboard - CPU and RAM are solid at 133MHz, late revision BX should be too, but I just couldn't get it stable above 124MHz. So it might be better to focus on the GA-6BXC as there's less to go long. That said, you can always try on the P2B-VM and fall back on the GA-6BXC if you hit problems.

Note that PCI overclocking is frequently the most sensitive. It's entirely possible that 133MHz FSB (with 133MHz RAM, 88MHz AGP but only 33MHz PCI due to 1/4 divider) is more stable than say 112MHz (with 112MHz RAM, 75MHz AGP but 37.5MHz PCI).

. i just took out 2 256mb pc100 sticks when i achieved 105mhz fsb, was going to try some 133 sticks but some say 133u and some 133 some dont say anything.. 🤣
is there a program i could use to display ram stick specs?

None that I would trust. The DIMMs have SPD EEPROMs that contain setting & timing info, which various tools can read out - but certainly in the early SDRAM period, SPDs were notoriously unreliable and sometimes even entirely absent. Don't trust them.

Instead, look at the chips. Assuming the info on them is correct (yes, re-marking chips was and is a thing, but much rarer than dodgy SPDs - and if you have lots to choose from, you can afford to ignore dubious stuff), they can tell you both compatibility and performance info. To keep it simple:
- i440BX accepts max 128Mb chips. As an unregistered DIMM supports max 16 chips, your max DIMM size is 128Mb*16/8=256MB, and only 256MB DIMMs with 16 chips will work at full capacitiy. If you use DIMMs with 256Mb chips, only half will be detected/used.
- for speed, look at the last digit of the chip model number, usually preceded by a dash ("-"). That gives the shortest access times in ns. That corresponds to these speed settings:

7 or lower: 133MHz CL2
7.5: 133MHz CL3
8.5: 100MHz CL2
9 or higher 100MHz CL3

Lower latencies also translates to better overclockability, but with PC133 SDRAM and an i440BX, it's highly unlikely the RAM will be the bottleneck. Still, if you have the option, take 7ns or faster chips.

dionb wrote:

i440BX accepts max 128Mb chips. As an unregistered DIMM supports max 16 chips, your max DIMM size is 128Mb*16/8=256MB, and only […]
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i440BX accepts max 128Mb chips. As an unregistered DIMM supports max 16 chips, your max DIMM size is 128Mb*16/8=256MB, and only 256MB DIMMs with 16 chips will work at full capacitiy. If you use DIMMs with 256Mb chips, only half will be detected/used.
- for speed, look at the last digit of the chip model number, usually preceded by a dash ("-"). That gives the shortest access times in ns. That corresponds to these speed settings:

7 or lower: 133MHz CL2
7.5: 133MHz CL3
8.5: 100MHz CL2
9 or higher 100MHz CL3

Lower latencies also translates to better overclockability, but with PC133 SDRAM and an i440BX, it's highly unlikely the RAM will be the bottleneck. Still, if you have the option, take 7ns or faster chips.

ok well that must explain why the Malaysia pc133(16chip) sticks ran at lower clocks in cpuz they dont display a - number i can find but, there is a "5264805ftt75" maybe the 75 at the end is an indicator of 7.5, the infineon pc133(16chip) does display a cl2 and a -7 marking on the chip and runs at lower clocks in cpu-z as indicated in the pics above.(aswell as the 512 stick which is currently in the machine but i cannot see any markigns because it has a heat sink that i cannot for the life of me get off without damaging it so i just left it alone 🤣)

i have not changed anything in the bios and am using the 512mb stick
in the bios i go to chipset features, the first option is
sdram configuration----SPD underneath which i cannot highlight to change are
CAS latency
RAS to CAS delay
SDRAM RAS Precharge Time
DRAM Idle Timer
but they change when changing through the options of sdram configuration
currently it is set to SPD but there are 7ns 143mhz/8ns125mhz/disabled as options, i assume i want to use 7ns with -7 cl 2(16chip) sticks?
as this provides lower numbers for the cas ras ect. If i am correct could this be a possible reason why i was not achieving 133mhz fsb? besides the pci/agp cards.
is it possible i could damage anything changing these values and fsb jumpers? imean ill probly try anyway lmao but its good to know.

Edit: btw there is another memory option right underneath the timing.
SDRAM MA wait state with 3 options slow/normal/fast its set to normal not sure what to use here.
actually heres a pic of the bios anything i need to change?

i ran it with the -7s option with the fsb set to 124mhz/pci 31mhz and it booted windows. gonma try 133/pci33mhz again.

I forgot to add one thing that may be important when following the guidelines as I written them down.
If you end up using several modules of the same make, but modules which for instance have slight differences in binning. If you make it a habit to have the slowest module in the first slot, you can prevent having odd errors down the road somewhere.

So I'd use a PC-100 cl3 module in the first slot and add similar modules in later slots, provided they were as fast or faster than the module I put in the first slot.
This can also help if you haven't used a system in a while and the BIOS gets reset for whatever reason, it will save you some frustration and maybe even a day of troubleshooting, and all you have to do is be mindful of which module you put in slot 1 (or slot 0 in some boards).

And that's basically one of the things I tend to do. If you have a choice and the effort in deciding a sequence is arbitrary, you might as well pick a sequence that has the least probability of giving you (or anyone else who might happen to work on your system later) extra trouble down the road.

If you want to see how fast your RAM can go, set timings loose (CL3, wait state slow etc), see how high you can go. Afterwards, enable the faster options one by one and if things get wonky, drop the speed till they're OK.

Well i ended up just re-installing windows messed something up.. went through all of my ram and re organized it by speed, not size.
I found a double sided 256mb -6 stick is this good?
where i am at now with the p2b-vm is a pentium III 450/100/512 @600mhz with a locked 4.5 multiplier 133FSB and x1 256mb dimm pc133 cl2 -7 and a radeon 7000(tried a riva tnt2 and i never thought that little card could push half-life so well in open-gl) in the bios i have it set to 7ns and a few things turned up, i followed this http://kpush.tripod.com/tweaking/id14.html the best i could, could not max it out unfortunately(Still the machine runs pretty well IMO).
pretty bad graphical glitches when i changed the 16/8 bit I/O Recovery Time, and i havnt tried to change Graphics Aperture Size and Video Memory Cache Mode.
now i just gotta throw in a 3dfx voodoo II Diamond Monster 8mb or voodoo II provieo 12mb, not enough room to sli them.
Also i found two other motherboards i thought were worse but ended up being alot better i think, they support coppermine cpus which i seem to have more of a selection anyways.
AOPEN AX63
ASUS P2-99B
i think im going to use these for the final 2 builds, LAN party before Christmas! 🤣
Thanks agian guys!

256MB 6ns double-sided is just about the perfect DIMM for an i440BX (or indeed any Sl1/So370) build. It should happily do CL2 at 133MHz and above.

Very nice to hear! ill be putting that in one of the copeprmines forsure then, i think they go to 150mhz