On 19 Feb 98 at 16:35, `bob boyd wrote:

> I currently have 2 ultra ide drives and 64mb edo simms. I was getting ready
> to order 2 10ns 64mb DIMMS. I'm looking for a improvement in Photo Shop
> performance and less swap file utilization. Can someone expand a bit on
> this 64mb max thing. Am I stuck with 64 unless I get a new board?

  So here's the deal:

  The onboard cache contains (a) cached data, and (b) tags describing
where the cached data comes from.  The tag data (b) is, on the TX
chipset, only big enough to identify items in the first 64MB of
memory.  Installing more than 64MB runs the risk of confusing the
cache; the simple way to avoid this is for the chipset to disable the
L2 cache in that case.

  Installing more RAM *is* likely to reduce your swap file I/O (which
isn't quite the same as "utilization", but it's more relevant when
talking performance[*]).  For big apps like PhotoShop, this might be
enough to more than offset the disabled cache.


[*]  Win95 allocates space in the swap file when an application asks
for memory, so it counts immediately against "swap file in use".  If
you really have enough RAM for the job at hand, it may never actually
swap any of the app's memory out to its reserved space in the swap
file.


David G