A7A266: Problems with 1GB DDR Memory?

[Paul Moloney]

I currently have 2 sticks of 256MB DDR memory
in my A7A266 with no problems (I've seen
many reports of others who have problems).

Since my system is fine, should I assume I'm able
to use 2 512MB memory sticks without a problem?
And can I mix sticks of different sizes -
could I have 512MB DDR + 256MB DDR for a total
of 768MB?

Thanks,

P.

 

[Paul]

I currently have 2 sticks of 256MB DDR memory
in my A7A266 with no problems (I've seen
many reports of others who have problems).

Since my system is fine, should I assume I'm able
to use 2 512MB memory sticks without a problem?
And can I mix sticks of different sizes -
could I have 512MB DDR + 256MB DDR for a total
of 768MB?

Thanks,

P.

If you go to Crucial.com or Kingston.com, and use
the search engine, you can get a feel for what size
modules work.

The 256MB module could have 8 or 16 chips on it,
depending on how old it is. The 512MB module is likely
to have 16 chips on it.

If your old module had 16 chips, then there is every
reason to expect a new module with 16 chips will work
as well. Modules with 32 chips, a popular but illegal
configuration for generic 1GB double sided modules,
won't work, in all but a few exceptional cases.

So, in conclusion:

1) Generally, if your motherboard manual says you have
support at the 512MB level, then those modules will
work. 512MB modules are hardly ever made in illegal
configurations. 1GB modules are frequently made in
illegal, bus overloading form, and should only be
bought from a name brand supplier (they generally
religiously follow the JEDEC standards). Single sided
eight chip modules are easier for the Northbridge to
drive, but not usually worth the price premium.
2) You can mix them, a 512MB with a 256MB. The programming
per slot on the memory controller is independent. It is
easier to guarantee a good result, if the characteristics
of the two modules match, because if they don't, then
you have to rely on the BIOS to figure out which module
is slower, and the BIOS uses the slowest timing of all
modules, to set up the memory. Some motherboards that
still have their original BIOS, will require you to swap
slots until they work (as the first release BIOS code
generally isn't too clever about that - some first release
BIOS cannot even read the SPD chip!).

If you found evidence in Google, that your chipset design is
flaky, then it could be that some brands work and others
don't, based on perhaps Tsu/Th differences or capacitive
loading differences of the modules. Try to pick a vendor with
good customer support, if you think that is going to be the
case. An online retailer from the Pricewatch list is not
likely to fit that description. A memory should come with a
lifetime warranty, as I found out the hard way, that cheap
memory with a 1 year warranty is not enough. And, an easy
returns policy.

HTH,
Paul

 

[billh]

I currently have 2 sticks of 256MB DDR memory
in my A7A266 with no problems (I've seen
many reports of others who have problems).

Since my system is fine, should I assume I'm able
to use 2 512MB memory sticks without a problem?
And can I mix sticks of different sizes -
could I have 512MB DDR + 256MB DDR for a total
of 768MB?

Thanks,

P.

As you say, you've seen many reports of others who have problems. The A7A266
isn't a particularly tolerant board for DDR memory but I also have had a
rock stable configuration with 512MB of Crucial memory. Don't forget there
is an undocumented (undocumented on the older boards anyway) jumper near the
AGP slot which will put an extra 0.1V onto the DDR memory for better
stability if needed.
Billh

 

[Jari Nieminen]

"Paul Moloney" <[email protected]> kirjoitti viestissä

I have 1GB on my A7A266-E. And it is very stable.
Used DDR-ram is Kingston KVR266X64C25/512 ValueRAM.

 

[Paul Moloney]

As you say, you've seen many reports of others who have problems. The A7A266
isn't a particularly tolerant board for DDR memory but I also have had a
rock stable configuration with 512MB of Crucial memory. Don't forget there
is an undocumented (undocumented on the older boards anyway) jumper near the
AGP slot which will put an extra 0.1V onto the DDR memory for better
stability if needed.

Thanks; I read about that jumper already. I must check my motherboard;
it's possible this was already set (I bought my PC off-the-shelf).
I've seen some
512 MB sticks of Nanya memory which I'll try.

Thanks,

P.