walterg74 wrote:Guys, one more that just came up…
For one of the motherboards the seller included a cache module what was the benefit of this do I want it how much is it supposed to be in relation to the memory installed?
Depends entirely on exactly what it is, and what is on the board for starters.
How cache works is a topic to read up on, but basically it's a small amount of much faster memory that sits between the CPU and the main memory. Anything that the CPU can fetch from cache is ready to be used much faster than stuff it needs to get from regular RAM. If you have no cache, any cache is a huge improvement. More is almost always better, regardless of amount of RAM. in 486 days you're usually talking about 128kB or 256kB of L2 cache. The difference between none and 128kB is huge, the difference between 128kB and 256kB is measurable, but much, much smaller.
All architectures have a cacheable limit - i.e. the maximum amount of RAM that the cache can cover. Calculating it gets a bit esoteric, but bottom line is that if you have a *LOT* of RAM, on some systems it pays to have a lot of cache too. This gets pretty relevant if you're running Windows 98 on a late Socket 7 system (as the amount of memory you might want to install could easily exceed the cacheable limit), but just as with the 16MB 30p SIMMs - if you hit cacheable limits on a 486 you're building an insane system 😉 I'm not aware of any combination of RAM, cache and chipset that has a cacheable limit below 32MB. For any 486 that has 30p SIMMs, anything over 16MB is completely period-incorrect. Consider that, indexed for inflation, 16MB of RAM cost ~EUR 750 to 1000 in 1995, and no normal program would even come close to using that much. So just aim for that sort of memory and forget about cacheable limits until you start building 1998-era socket 7 stuff 😉