🚀 go-pugleaf

In article: <oKMISAAuP+cxEwZ2@mwb.u-net.com>  Marcus Bainbridge <marcus@mwb.u-net.com> writes:
> John Naismith <John@naismith.demon.co.uk> wrote:
> 
> >I've just checked & these chips have 128 pins on each. Seems a little excessive 
> >for 64 bit cache ? 
> >
> >64 bit data + 32 bit address + ?
> >
> >Anyone know what the hell they are?
> 
> Well, if you have a part number... :->
> 
> With QFP and similar devices, they come in standard pin arrays, so there
> could be a lot of power pins (ISTR something about quad cache having a
> particular problem with routing power around the silicon..?)
> 
> But if they are cache controllers, then then have to access 64-bit data
> and 20-bit cache address (say), plus chip selects, interfaces with main
> memory (could be on a different bus and multiplexed by the cache
> controller, so call it another 64-bit data and 32-bit DRAM address).
> All adds up...
> 
> If I could find the manual for my motherboard (never trust a woman to
> tidy up - you'll never find anything ever again...), I could find out a
> bit more about the Triton chipset.  Maybe it's on the Intel CDs at
> work..?
I have two motherboards here, both using the same chips. One uses just
two chips, Intel Partno:S82438fFX. This board has a COAST socket, and these
_are_ the cache interface chips from the PCIset. The other has four, all
the same size package, and in this case, the extra two, are the memory.
It appears that machines implementing pipeline burst mode cache, have
these larger cache controller chips. The Triton chipset, uses them on such
machines.
Adding to the above comment, about the number of pins needed, you also
have to add the memory control bits, from both sides, and the tag data. It
uses a lot of pins. Machines without P/B cache, seem to use a single
larger chip for the cache control, but the layout described, is common, in
a lot of motherboards. The puzzling/worrying part, is the addition of the
strange labelling as 'write-back', and the strange utilisation of the pins.
Given the recent spate of stories about fakes, the only real solution, is
to use a diagnostic, that tells you what you have actually got, and stop
worrying about how the particular manufacturer has implemented it.

Best Wishes

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