[rescue] Re: Vesa Local Bus video cards

Tim H. lists at pellucidar.net
Tue Apr 1 09:45:03 CST 2003

On Tue, 01 Apr 2003 15:52:58 +1200
Gavin Hubbard <ghub005 at xtra.co.nz> wrote:

> Incidentally I've seen early Pentium systems (60 & 66MHz) with VLB but
> no PCI. I've seen early Pentium motherboards with both VLB and PCI.
> I've even seen some 486 motherboards with PCI. No hard & fast rules it
> seems.
> Regards,
> Gavin

Actually, the PCI/VLB boards tended to be slower than either one alone,
it was an attempt at bet hedging when the winner of the local bus vs.
PCI was not yet clear.  Just think where we would be if local busses had
won, and video and IO were still running at processor speed on PCs (or
for that matter, if memory were still running at processor speed). At
one point I had a VLB board with an Intel 486DX50, the one that actually
attempted to run the isa bus at 50MHz, unfortunately I couldn't get a
stable set of cards at 50MHz, and had to underclock to 40 to get it to
be stable.  That was the fastest 486 ever for IO, if you could find
cards that would run with it.  For practical purposes the AMD 486DX4/120
(clock tripled 40 MHz) was the fastest, because it ran the bus within
spec.  The fastest desktop machine I ever saw (subjective click to
application time) was a 486DX2/66 running WfW, That thing would sit you
back in your chair.


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