Mo RAM, Mo Problems (2025)(fabiensanglard.net) |
Mo RAM, Mo Problems (2025)(fabiensanglard.net) |
There was a kernel patch for this chipset back then, which treated all memory above the lower 64MB as a RAM disk, which could then be used as swap space.
This prioritized the faster portion of RAM while still having very fast swapping.
Intel being Intel, back then and now.
It was only a few weeks ago that I found out the original BeBOX computers would switch off L2 cache when running in dual CPU mode. It was just a limitation of the memory controller. Again, the thinking of, if you need the extra compute over memory bus it would be a worth while trade off.
The idea was that nobody in their right mind would at the time populate that particular consumer motherboard/chipset with hundreds of megabytes of RAM because it would be hilariously expensive. If you needed that kind of RAM, you were purchasing a much more expensive workstation anyhow.
By the time 384MB was a merely expensive amount of RAM, nobody would be interested in installing it in a Pentium. Those were the days when Moore's Law was still a very big deal. For that reason the firmware probably never received an update to fix the problem, even if that were possible.
The docs on that motherboard sort of suggest that the motherboard could cache up to 512MB. This motherboard uses the new pipelined burst cache technology with 512K size and the memory cacheable size from 64MB to 512MB. I can't imagine they ever actually tested that.
Besides web sources, logic dictates this as well: Since dual-cpu was its selling point, it wouldn't make sense to ship a disabled L2 implementaton on the mobo at extra cost. There was no single-cpu model.
https://www.corsair.com/us/en/explorer/diy-builder/memory/2-...
We traded the 'Mo RAM' for 'Mo Layers,' and in the process, we lost the ability to reason about what the hardware is actually doing. Sanglard’s breakdowns are always a sobering cold shower for those of us pampered by modern GC and JITs
There are workarounds, of course. For instance, the A1208 expansion has a jumper that limits added memory from 8MB to 4MB explicitly so that PCMCIA can be used.
And just disabling the upper memory in order to be able to use the PCMCIA slot is a really lazy solution. Kinda typical for Commodore, though. 3rd party vendors offered better designs for their memory expansions.
Imagine young would-become engineers at the time finding that adding that second stick to their laptop did in fact, not make their systems magically faster.
>128MB DIMM: May 1997 $300. July 1998 $150. July 1999 $99. September 1999 Jiji earthquake happens. September-December 1999 $300. May 2000 $89.
>Then overproduction combined with dot-com boom liquidations started flooding the market and Feb 2001 $59, by Aug 2001 _256MB_ module was $49. Feb 2002 256MB $34. Finally April 2003 hit the absolute bottom with $39 _512MB_ DIMMs
In 1999 512MB could cost $400, but it could also cost $1200 :)
It looks like Anandtech listed 128Mb for $300 (not inflation adjusted) in 1997. It fell to $150 in 1998 and by 1999 you could buy it for $100.
So 512Mb RAM by the end of 1999 for ~$200 was plausible.
So yes, even when your cpu could address similar size of ram, possible it don't have enough page cache for your application.