I can only think of that no-caching disadvantage

I would only stick one of those SIMMs in and call it a day.

None at all - unless you're planning to run an old fashioned server/BBS or install Windows NT 3.51.

For DOS / Win3.x - very little - I recall one Windows program that was HUGE, and needed extra RAM.
For Win9x ... throw memory at it.
If trying to run a GUI Linux on 486 (not recommended), then throw memory at it - maybe you'd get away an XFCE or LXDE environment

So basically 32MB is enough. I guess I'll be better off with using that RAM in a socket 7 build.

Windows 98 or especially 2000. It needs gobs of RAM.

And no 32 MB is not really enough for a high end 486. I wouldn't go lower than 64

You could always throw XMSDISK at it and make a huge RAM Drive I suppose.

bragging rights.

Realistically 8MB is all you need in a 486, unless you're doing something that really requires a Pentium.

Anonymous Coward wrote:

bragging rights.

Realistically 8MB is all you need in a 486, unless you're doing something that really requires a Pentium.

Not true at ALL. Many later 486s shipped with more than 8MB from the factory. The only reason it didn't ship with more is because ram used to be expensive.
Even Windows 3.1 is tight in 8 MB

By the same logic, you could say all you need now is 1 GB of RAM. Sure you might be able to get by with it but RAM is dirt cheap so why
not use the headroom?

RAM is dirt cheap? Maybe we're living in different dimensions but around here the prices of DDR3 RAM are almost twice as high as they used to be in the beginning of 2012.

Half-Saint wrote:

RAM is dirt cheap? Maybe we're living in different dimensions but around here the prices of DDR3 RAM are almost twice as high as they used to be in the beginning of 2012.

Yes it has gone up but compared to the 1990s it is dirt cheap.

Since that wasn't mentioned, you can obviously use it for disk caching (smartdrv). This is especially useful if you use a period correct HD.

Half-Saint wrote:

I found two more 32MB 72-pin SIMMs in my stash and I'm wondering, what the advantages of having 128MB in a 486 system would be? Back in the day, I only had 8MB in my 486DX-40 and it worked rather well.

You are quite right. I remember my 386SX-16 was acceptably happy with 5MBs of RAM in Windows 3.1 (1992-1994). I also remember my 486DX-33 was acceptably happy with 4-6MB RAM in Windows 3.1 (1994) and with 8MB RAM in Windows 95 (1995).

In 1994, having 64MB of RAM in a machine (we had some special purpose machines at the institute) was almost tripling the price of any given 486. At that time, 8MB was common for over-average machines.

By the time over average standard was 16-32MB, most of the new purchases was Pentiums already.

So in short, there is no real benefit, since almost any software available at that time, and supposed to run on a 486, was happy with 8-16MB RAM at the highest.

Aside from all these, if you are guy like me, and like maxing out the upgrade limit of any given hardware and/or getting special pleasure from creating "ultra mega dream machines of the past", you can just go ahead and put them in, of course... 🤣

My personal preferences in the subject, based on nothing scientific, are; 32/64MB for late-386 and 486 builds, 128/256MB for Socket 7 bulds, and 256/512MB for PII/PIII (non XP) machines.

Anonymous Coward wrote:

bragging rights.

Realistically 8MB is all you need in a 486, unless you're doing something that really requires a Pentium.

Correction 16MB is al you need in a 486. I knew that back in the day most machine came with 8MB stock, those where mostly upgraded to 16MB of ram.. Because some games / programs actually needs more.
But sometimes 16MB is really the edge if you also running memory making programs, so 20MB is really really save. Really not more needed then 20MB..

Half-Saint wrote:

I found two more 32MB 72-pin SIMMs in my stash and I'm wondering, what the advantages of having 128MB in a 486 system would be? Back in the day, I only had 8MB in my 486DX-40 and it worked rather well.

Are these FPM or EDO? As not many 486 chipsets would support EDO.

Mind the cacheable limit. For SIS 496/497 it's 64MB for 512kWB or 256kWT, 32MB for 256kWB or 128kWT, if I recall it correctly. 128MB of RAM is only useful if you have a whooping 1MB of L2.

kixs wrote:

Half-Saint wrote:

I found two more 32MB 72-pin SIMMs in my stash and I'm wondering, what the advantages of having 128MB in a 486 system would be? Back in the day, I only had 8MB in my 486DX-40 and it worked rather well.

Are these FPM or EDO? As not many 486 chipsets would support EDO.

I have no idea, only know that they work 😀

RacoonRider wrote:

Mind the cacheable limit. For SIS 496/497 it's 64MB for 512kWB or 256kWT, 32MB for 256kWB or 128kWT, if I recall it correctly. 128MB of RAM is only useful if you have a whooping 1MB of L2.

It write through mode, I am 99% sure it is 4KB of cache is needed per megabyte of RAM

The most I've ever had in a 486 is 64MB. It helps if for some reason you have desires to do things beyond what a 486/5x86 can really do well anyway. 😀

32MB was certainly sitting pretty when these machines were in their heyday. I didn't have 128MB until like 1999 in a Pentium 3.

swaaye wrote:

The most I've ever had in a 486 is 64MB. It helps if for some reason you have desires to do things beyond what a 486/5x86 can really do well anyway. 😀

Or if you run OS/2, which, as I remember, needs more RAM than Windows 9x. I run 64Mb because a) I use OS/2 b) I have 512K cache to run it all cacheable in WB mode. Other than that, the only reason I see for anything more than 32Mb is playing games like Ultima VII with RAMdisk. 128MB is enough for a middle-end PII, why bother with 128MB on 486? It reduces the speed a lot as you have to go WT or run it uncached or find a board that supports 1024k modules and the modules themselves, when it's already a challenge to get 8 512k modules and a motherboard to fit them in. One hell of a job if you ask me, and for what?