🚀 go-pugleaf

 >> David Longley <David@longley.demon.co.uk> wrote:
> >> 
> >> >I have a curious problem which I need a definitive technical solution to.
> >> >
> >> >Motherboard:  VL (one slot, est ISA)
> >> >CPU        :  i486-66DX2
> >> >Cache      :  256K
> >> >RAM        :  4 x 80ns + 4 x 100ns parity
> >> >BIOS       :  AMIBIOS 1991
> >> >
> >> >Problem..
> >> >
> >
> >I had a similar problem when I upgraded from an Intel 486dx33 
> >chip to an Intel 486dx4/100.  I had flaky problem when I would 
> >do certain things, random system lockups, weird display 
> >problems etc.  It would work fine when I disabled my L2 cache.  
> >But when my cache was enabled, my computer was much slower (as 
> >measured by Norton System Information).  With the cache enabled 
> >I was just a little above a 486dx33, with it disabled I was 
> >almost 3x faster than a 486dx33.  
> >     I called Intel and they told me to disable my L2 cache....  
> >Everything seems to work ok now, but it bothers me that I have 
> >this cache sitting on my MB not being used.  Anybody have any 
> >suggestions?
> >
> >        486dx33 -> 486dx4/100
> >        256K - 20ns cache (currently disabled)
> >        AMI Bios 1992
> >
> >Maybe I need faster cache or something.  Please let me know if 
> >you get your problem fixed.
> 

I have a similar (if not same) problem as we speak.  I just
upgraded my L2 cache to 128k (my system uses 5 32kx8 SRAMs).
The manual states that the TAG SRAM (between the CPU and the
other four SRAMs) should be 20ns and the other four should be
25ns.  I purchased five 20ns SRAMs and installed them... Suddenly,
memory reads were much, much SLOWER than normal.  When the L2
cache is disabled, everything runs smoothly.

I contacted the technical support department for my system,
and they dug and dug until they found a long-forgotten technical
bulletin that stated the tag SRAM chip had to be FASTER than the
others... That is why the manual stated to use one 20ns and four
25ns chips... The tech said four 20ns and one 15ns would work, so
I have the new 15ns on order... Plan to install it Friday March 22nd.
I will post my results if I am successful.

Anyway, your situation looked familiar... Thought I'd add my
two-cents-worth...