SDRAM memory

[ALAIN DAVELUY]

Hell
I have an old PC Siemens Fujitsu 166 MMX with 128 Mo SDRAM 100v Mhz (2 X
64Mo, one 222-622 , one 333-622)
Can I take an 128 Mo memory in place of one 64Mo to ahve 192 MO
The chipset is an intel 82493TX 430TX
Thanks !

[Paul]

I tracked this down, using the document number I already had on file.
You may not be able to find this on the Intel site any more.

http://www.clannad.co.uk/datasheets/chipsets/29055901.pdf

PDF page 55

Table 13. Minimum (Upgradeable) and Maximum Memory Size for each configuration (SDRAM)

SS DS Addressing Row Col Min Max
x64 x64 1 row 6 row <=== not sure how six rows is possible???
8M 8 8M 16M Asymmetric 14 9 64 MB 256 MB <=== 256MB is four rows, sufficient signals
8Mx8 exist for four rows.
chip

Check the details of your cache configuration, before adding too
much RAM (uncached RAM is slow). There is a 430TX article here.

"430TX" August 1, 1997

https://www.anandtech.com/show/72/6

"The 256MB maximum memory limit of the TX chipset is blurred by
its meager 64MB cacheable memory area which takes us back to
the old days of the FX chipset."

Device does not extent past 256MB of address space
for the DRAM controller.

It is 2x128MB max.

The controller is four bank, according to the datasheet.

A sampling of two motherboard manuals, showed they only
had two SDRAM DIMM slots.

The smaller DIMM (64MB) would go nearest to the processor.
There was some superstition at the time, that DIMMs should
be installed in order of size. Whether that is true or not,
I really can't be sure. On a two slot design, that gives
better SI on the bus, to put the "heavy" DIMM last.

In the past, designs were really limited on gate count, and
decoding logic was pretty crusty. That's why they did not
have an "anything goes" design style on RAM population. It
was only much later, there was both time and a wealth of
gates, to do better decoder design inside the chip.

You should not mix memory types. The sample motherboards
I could find, had both SIMM slots and DIMM slots. I would
not use both.

If a four bank memory controller is used with a motherboard
with three SDRAM slots, then the second and third slots share
decode signals, and SS DIMMs go in each. You can do "DS DS --"
or you can do "DS SS SS" if there were three DIMM slots.
Intel was doing that in some later designs. It's possible
430TX boards did not ship that way.

Considering the botched L2 cache, I would test with just
the single 128MB installed and benchmark it. Compare 64MB
speed to 128MB speed, before installing all 192MB.

You can use memtest for this, which has a bandwidth indicator
on the main screen. My 440BX would do about 300MB/sec or so
(because it wasn't overclocked).

Paul

[Bob F]

Why did I get a bunch of headers from 2005-6 showing up in several
groups today?

[Paul]

Yeah, I didn't notice the date.

There were some from 2017 that showed up today too.
Just not in this group.

There are also current messages which are arriving late.
That has been going on for at least a month or so.

Paul

[Marco Moock]

It seems to affect eternal-september only. I also use it (like you) and
I also got old articles an many groups.