"DB" said:
er no I didnt.....how do I do that Charles, previously I has 256 but now
shows 512
Dave - thanks
He is talking about the CLRTC jumper. In your manual, go to section
1.11 "Jumpers". Item #3 in that section tells you how to clear the
CMOS. Clearing the CMOS will likely cause the onboard clock to be
reset, and you'll have to re-enter BIOS settings. The most important
part of the procedure, is to unplug the computer, to protect the
ORing diode in the standby power circuit.
If you can boot the computer, I would start with a copy of CPUZ from
www.cpuid.com . I believe CPUZ has the ability to dump the contents
of the SPD chip on the DIMM. Perhaps it will tell you something about
the design of the DIMM.
I would also test the new DIMM by itself, removing the old memory
DIMM. That might make it easier to figure out what the computer
sees or doesn't see.
Your manual says you may use 3*1GB DIMMs (with some restrictions
on memory clock rate, as three double sided DIMMs is a heavy
capacitive load to drive). The KT400 will have some number of
memory address bits, and a certain number of row and column
address bits are needed to address the whole memory.
When a chipset says it is limited to a 1GB stick, that might
mean it could only deal with 64Mx8 chips. It might only have
enough memory address bits to do that. If the DIMM had 128Mx4
chips on it, that might mean the DIMM needs one more memory
address bit than the chipset has to offer. The consequence of
using (16) 128Mx4 chips, might be that only 512MB can be seen.
A construction more likely to work is (16) 64Mx8 chips, which
logically is two "ranks" of memory. Those DIMMs tend to be
more expensive than other potential constructions.
So, have a look at the SPD info from the DIMM, or if your
memory vendor had a shred of honesty, there might have
been some info suitable for warning you of the potential
for problems.
For example, here is an advert from Pricewatch, "coded" to
indicate the potential for trouble. When a vendor starts
naming "compatible" chipsets, it implies something funny
about the RAM.
http://www.pricewatch.com/prc.aspx?i=33&a=5025
"MemoryPRO - D400-1284-1G
MemoryPRO High Density 1GB DDR PC3200 DDR400 184-Pin DIMM
Memory for KT400 KT600 & SIS 645 648 648FX 746FX Chipsets
& more."
The "high density" implies the deeper addressing RAM chips,
of 128M by 4 bits wide memory chips ("high density" is not
a precise term, so I treat this as a hint). Their part number
also hints at that. The naming of the chipsets means at the
least, that the DIMM places more capacitive load than normal
on the memory bus, and that list of chipsets can probably
drive at least one DIMM. You might not be able to drive 3
of these, at full speed. Since datasheets for the above named
chipsets are not likely to be available, it is hard to say
more about whether the row/column addressing bits are
sufficient to address 128 million locations on a single DIMM
rank. (If the product support 2GB DIMMs, then the answer would
be yes.)
See if you can swap for a 16 chip 64Mx8 chip type DIMM. Your
vendor will need more cash for the transaction. It
will have normal bus loading, and might be fully
addressable by your KT400 Northbridge.
You can see the difference in price here. At one time, vendors
like this gave no warning whatsoever, about the fitness of
their products, and I guess a stready stream of returns
and fights about restocking fees, is improving the quality of
the adverts.
http://www.portatech.com/catalog/memory.asp?ID=285
Just some guesses,
Paul
