>I'm going to upgrade to a mboard with PCI, and I'm wondering if I should
>get a 586 (ahem, pentium) mboard since I've heard they have wider memory
>access buses.  Is this true, and does it make a significant performance
>impact?

Yes, the Pentium has a 64-bit data bus (internally from the cache, 128
bits, if I'm not mistaken).  486-class chips have an external 32-bit
data bus (not familiar with the internal width).  The extra width
helps keep the processor from stalling -- it burst fills the internal
cache pre-fetch queue much faster.  This is important with
clock-doubled (and more-tupled) internal vs. external speeds.  You
could think of doubling the bus width as, in a way, doubling the
bandwidth of a 32-bit bus, thereby making back the speed lost by
doubling the internal speed vs. external speed of the CPU.

-----------------------------------------------------------------------------
  Michael L. VanLoon                                 michaelv@HeadCandy.com
       --<  Free your mind and your machine -- NetBSD free un*x  >--
     NetBSD working ports: 386+PC, Mac 68k, Amiga, HP300, Sun3, Sun4,
                           DEC PMAX (MIPS), DEC Alpha, PC532
     NetBSD ports in progress: VAX, Atari 68k, others...
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