Maximum and mixed RAM in Tyan Trinity 400 S1854?

My friends have a computer with a Tyan Trinity 400 S1854 motherboard
with one stick of Crucial 128MB PC100 RAM in it. It runs Windows XP, very
slow of course and they wanted to add memory.

I tried replacing the RAM with 3 sticks of pqi POWER Series 256MB 168-Pin
SDRAM PC 133 System Memory (Model MS3856UOE-P28) but there were constant
black screens and reboots.

When I put in the new memory I didn't change anything in the BIOS.
I didn't think I had to.

What's the most memory that motherboard can take? I've heard it's 1.5GB
but haven't seen any verification.

What's the cheapest 256MB or 512MB RAM that we can buy that'll work well
with it?
(The PQI RAM was about $26 a piece from Newegg but I see that Crucial
memory is about 3 times the price.)

Is it possible to mix-and-match PC100 and PC133 RAM?
Could we put in 2 sticks of 512MB along with the original 128MB stick?

Thanks for any assistance.

7h95g wrote:
>
> My friends have a computer with a Tyan Trinity 400 S1854 motherboard
> with one stick of Crucial 128MB PC100 RAM in it. It runs Windows XP, very
> slow of course and they wanted to add memory.
>
> I tried replacing the RAM with 3 sticks of pqi POWER Series 256MB 168-Pin
> SDRAM PC 133 System Memory (Model MS3856UOE-P28) but there were constant
> black screens and reboots.
>
> When I put in the new memory I didn't change anything in the BIOS.
> I didn't think I had to.
>
> What's the most memory that motherboard can take? I've heard it's 1.5GB
> but haven't seen any verification.
>
> What's the cheapest 256MB or 512MB RAM that we can buy that'll work well
> with it?
> (The PQI RAM was about $26 a piece from Newegg but I see that Crucial
> memory is about 3 times the price.)
>
> Is it possible to mix-and-match PC100 and PC133 RAM?
> Could we put in 2 sticks of 512MB along with the original 128MB stick?
>
> Thanks for any assistance.

I think I found one reference in Google to someone who had run
3 x 512MB SDRAM on the same chipset.

First, check that your OS can handle the memory. Win98 has a
trouble-free limit of 512MB total, and from 512MB to 1024MB if
you fiddle with the "Maxfilecache" option. If you multiboot Win98
and some other more capable OS, the "MaxPhysAddr" option is also
useful for preventing Win98 from seeing more memory (like if you
put 1536MB in it total).

If you got black screens, it is possible a stick was bad in the
new memory. You can test one new stick at a time with memtest86+
from memtest.org , and that will tell you if there are any really
bad spots in the memory. The Prime95 torture test (mersenne.org)
can be used once you boot into Windows (or Linux). It should be
able to run for hours error free if the memory is truly good stuff.
Prime95 will error out within seconds, if the memory is not good
stuff.

Testing is one thing that separates cheap memory from good
memory. When you buy the cheapest you can find, be prepared to
return some of it to your supplier. If you know you'll be returning
some of the sticks you buy, a supplier with a good customer service
reputation helps. So does a reasonable warranty. I've had a couple
batches of RAM go bad on me just past one year of use, but all the
Crucial I bought is still perfect. Caveat emptor - buyer beware.

Paul