PA-2013 Bios settings for Crucial 256MB 133Mhz CL2

I was sucessessfully running three (3) Crucial 256MB, 168 Dimm, Sdram
PC133, 32Meg x 64, Unbuffered, Non-parity, 7.5ns, 3,3V, CL=3 sticks in
my FIC PA=2013 Rev. 2 E-O036, K6=3/450, MB. I purchased the same as
above, but CL=2, and I can only get two sticks in the first two slots
to run successfully. I have tried all 3 sticks in the first two slots
and system runs fine. But when I try putting the 3 sticks (Crucial#
CT32M64S4D7E.16LT )in together (in all 3 slots), I either don't get a
good memory count, or if it does (just once) I can't get the complete
Bios bootup (it stops) - I don't get to where it searches HD for
Windows 98SE. Question: Why will 3 CL=3's work and not 3 CL=2's (only
two will work at one time)? Perhaps my BIOS memory settings are wrong
for CL=2. But why do two work but not three?
Thanks for any help. Gibby

"Gibby" <> wrote in message news: m...
> I was sucessessfully running three (3) Crucial 256MB, 168 Dimm, Sdram
> PC133, 32Meg x 64, Unbuffered, Non-parity, 7.5ns, 3,3V, CL=3 sticks
> in my FIC PA=2013 Rev. 2 E-O036, K6=3/450, MB. I purchased the
> same as above, but CL=2, and I can only get two sticks in the first two
> slots to run successfully. I have tried all 3 sticks in the first two slots
> and system runs fine. But when I try putting the 3 sticks (Crucial#
> CT32M64S4D7E.16LT )in together (in all 3 slots), I either don't get a
> good memory count, or if it does (just once) I can't get the complete
> Bios bootup (it stops) - I don't get to where it searches HD for
> Windows 98SE. Question: Why will 3 CL=3's work and not 3 CL=2's
> (only two will work at one time)? Perhaps my BIOS memory settings
> are wrong for CL=2. But why do two work but not three?
> Thanks for any help. Gibby
>
Timing is tighter for CL=2. There's probably too much capacitance
in the circuit board traces and the signal rise times get sloppy with
three sticks just because there are more traces to drive.

"L David Matheny" <> wrote in message
news:bqguqc$22scpj$...
| "Gibby" <> wrote in message
news: m...
| > I was sucessessfully running three (3) Crucial 256MB, 168 Dimm,
Sdram
| > PC133, 32Meg x 64, Unbuffered, Non-parity, 7.5ns, 3,3V, CL=3
sticks
| > in my FIC PA=2013 Rev. 2 E-O036, K6=3/450, MB. I purchased the
| > same as above, but CL=2, and I can only get two sticks in the
first two
| > slots to run successfully. I have tried all 3 sticks in the first
two slots
| > and system runs fine. But when I try putting the 3 sticks
(Crucial#
| > CT32M64S4D7E.16LT )in together (in all 3 slots), I either don't
get a
| > good memory count, or if it does (just once) I can't get the
complete
| > Bios bootup (it stops) - I don't get to where it searches HD for
| > Windows 98SE. Question: Why will 3 CL=3's work and not 3 CL=2's
| > (only two will work at one time)? Perhaps my BIOS memory settings
| > are wrong for CL=2. But why do two work but not three?
| > Thanks for any help. Gibby
| >
| Timing is tighter for CL=2. There's probably too much capacitance
| in the circuit board traces and the signal rise times get sloppy
with
| three sticks just because there are more traces to drive.
|


I think you are warm with this analysis. It might be better said that
the sdram device output loading on the memory interface and sdram
circuits is higher with 3 versus 2 unbuffered output sdram sticks.
The capacitance loading is probably substantially the same, as the
capacitance (residual) is attributable to the mobo runners or traces
layout. All of the mobo memory traces get driven no matter how many
sticks you are using.

--
Best regards,
Kyle

"Kyle Brant" <> wrote in message news:bqhhq1$21fmjr$...
> "L David Matheny" <> wrote in message
> news:bqguqc$22scpj$...
> | "Gibby" <> wrote in message
> | news: m...
> | > I was sucessessfully running three (3) Crucial 256MB, 168 Dimm,
> | > Sdram PC133, 32Meg x 64, Unbuffered, Non-parity, 7.5ns,
> | > 3,3V, CL=3 sticks in my FIC PA=2013 Rev. 2 E-O036,
> | > K6=3/450, MB. I purchased the same as above, but CL=2,
> | > and I can only get two sticks in the first two slots to run
> | > successfully. I have tried all 3 sticks in the first two slots
> | > and system runs fine. But when I try putting the 3 sticks
> | > (Crucial# CT32M64S4D7E.16LT )in together (in all 3
> | > slots), I either don't get a good memory count, or if it does
> | > (just once) I can't get the complete Bios bootup (it stops) -
> | > I don't get to where it searches HD for Windows 98SE.
> | > Question: Why will 3 CL=3's work and not 3 CL=2's
> | > (only two will work at one time)? Perhaps my BIOS
> | > memory settings are wrong for CL=2. But why do two
> | > work but not three?
> | > Thanks for any help. Gibby
> | >
> | Timing is tighter for CL=2. There's probably too much
> | capacitance in the circuit board traces and the signal rise
> | times get sloppy with three sticks just because there are
> | more traces to drive.
> |
> I think you are warm with this analysis. It might be better said
> that the sdram device output loading on the memory interface
> and sdram circuits is higher with 3 versus 2 unbuffered output
> sdram sticks. The capacitance loading is probably substantially
> the same, as the capacitance (residual) is attributable to the
> mobo runners or traces layout. All of the mobo memory
> traces get driven no matter how many sticks you are using.
>
Yes, it's overall loading on the memory interface drive circuitry
that causes the timing problems, but surely the SDRAM circuit
board traces have some capacitance, too.

Can I take from this thread that CL=3 is recommended if using all
three slots, (3x256) and would using even one stick of CL=2 be a
bad idea on the PA-2013 if filling all slots.

Den

That's how I would take it. CL=2 memory will run just fine at CL=3,
though, so just set the BIOS to run all the memory at CL=3.

--Alex


Den wrote:

> Can I take from this thread that CL=3 is recommended if using all
> three slots, (3x256) and would using even one stick of CL=2 be a
> bad idea on the PA-2013 if filling all slots.
>
> Den

"Alex Zorrilla" <> wrote in message news:...
> That's how I would take it. CL=2 memory will run just fine at CL=3,
> though, so just set the BIOS to run all the memory at CL=3.
>
Thanks will try this if (taps foot while waiting for Crucial to repeat
their last good offer, but I think I have missed the last boat).

Den