Too late to edit - I just saw that the Vaio in fact had the 430TX chipset, not the 430FX. Both were artificially capped at 64MB of fast RAM, as they were late Pentium chipsets, and Intel rather wanted to sell the then-new Pentium II chips and chipsets if you wanted to have more memory.

In the modern era we'd probably repurpose NUMA support if this issue came up again, so that tasks would prioritize the fast portion of memory but the remainder would be fully usable as RAM (with fewer of the extra copies you'd have from "swap" use).