Adding 384MiB of SDRAM to a 1997 Quake PC cut framerates 25% because the 430FX chipset stops L2-caching memory above ~64MB.
Key Takeaways
The Intel 430FX chipset and similar 1990s chipsets only L2-cache up to 64MB; RAM above that threshold runs fully uncached, wrecking performance.
Windows 95 and NT load from the top of RAM down, so any OS load on an overfilled machine hits the uncached region first.
The XA100 motherboard (1998) advertised 512MiB cache support but only cached roughly 128MiB in practice, leaving the rest unaccelerated.
Removing RAM was the fix: stripping back to one SDRAM module restored Quake benchmarks from 33 fps to 44 fps on a Pentium MMX 233MHz.
384MiB of 1997 SDRAM was purchased for $60 in 2025; the article claims its original retail value was roughly $40,000.
Hacker News Comment Review
The cache ceiling problem is not purely retro: AM5 systems today may lose EXPO/XMP profiles with four DIMM slots populated versus two, the gap just less dramatic.
Around 2000, a Linux kernel patch handled the same 430FX limitation by treating memory above 64MB as a fast RAM disk used as swap, keeping hot pages in cached space.
The claimed $40,000 historical retail value for 384MiB drew skepticism; period pricing records of $7-10/MB put the figure closer to $3,840.
Notable Comments
@Iflal: “we traded the ‘Mo RAM’ for ‘Mo Layers’” – modern services OOM-ing in 2GB containers mirror the same failure to reason about what hardware is actually doing.
@krige: Amiga 600/1200 shows the same class of tradeoff: adding more than 4MB disables the PCMCIA slot due to addressing conflicts; the A1208 expansion includes a physical jumper to explicitly cap RAM at 4MB.
