P4P800 Dual DDR Issue

  • Thread starter Thread starter Jesse
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Jesse

Hi, I'm trying to use 2 x 256mb twinmos dimms with ch-5 winbond chips in
dual ddr mode on my asus p4p800 motherboard. However whenever the dimms are
in a dual ddr configuration the machine refuses to boot with a 2:3 (266mhz)
memory divider. I can use the (333mhz) 4:5 divider but my fsb max's out at
only ~256mhz -- even to maintain that mem has to be at 2.85v with relaxed
latency's, lowering the voltage or mem lat's makes the machine do weird
things like try an easyrecovery on boot or the display corrupts/locks in
bios...

With a 1:1 (400mhz) ratio in dual ddr mode things seem as they should be --
fsb (mem also) can be pushed to 244Mhz+ which is what this ram should be
able to do. In single channel mode it's 100% stable at 175MHz fsb, using a
2:3 mem ratio, 2.75v and low memory lats of 2:2:2:5.

I paid quite a bit for those dimms with high dual ddr fsb's in mind, my old
transend ddr333 can almost do as well! Any help or suggestions on the matter
would be appreciated.

Thanks, Jesse

CPU: P4 2.4C
RAM: 2 x 256mb twinmos dimms with ch-5 winbond chips
M/B: Asus P4P800 rev 1.02 w/1008 bios
 
Hi, I'm trying to use 2 x 256mb twinmos dimms with ch-5 winbond chips in
dual ddr mode on my asus p4p800 motherboard. However whenever the dimms are
in a dual ddr configuration the machine refuses to boot with a 2:3 (266mhz)
memory divider. I can use the (333mhz) 4:5 divider but my fsb max's out at
only ~256mhz -- even to maintain that mem has to be at 2.85v with relaxed
latency's, lowering the voltage or mem lat's makes the machine do weird
things like try an easyrecovery on boot or the display corrupts/locks in
bios...

With a 1:1 (400mhz) ratio in dual ddr mode things seem as they should be --
fsb (mem also) can be pushed to 244Mhz+ which is what this ram should be
able to do. In single channel mode it's 100% stable at 175MHz fsb, using a
2:3 mem ratio, 2.75v and low memory lats of 2:2:2:5.

I paid quite a bit for those dimms with high dual ddr fsb's in mind, my old
transend ddr333 can almost do as well! Any help or suggestions on the matter
would be appreciated.
Click to expand...

I don't understand the problem. 244 MHz on the RAM is an ungodly
overclock, be happy with it. Why do you want to run it slower? I'm
guessing you're just interpreting the dividers wrong, for any fsb over
200(800) you should be using the 320 setting. And 256 on the fsb is
probably about as high as a 2.4C will go.
 
Hey - Sorry, if i wasn't very clear on that.

I have essentially established is that the memory can run at up to 244MHz
while in dual ddr mode and the cpu can boot and run stable at a 275MHz fsb.

What i would like to do is put the 2 together -- use a 275MHz fsb with a 4:5
mem ratio in dual ddr mode (mem would be @ only 220Mhz).

244 * 12 = 2928MHz (amazing 1:1 ram freq)

250 * 12 = 3072MHz (3:2 mem, stable - why am i stuck at this?)

275 * 12 = 3300MHz (where i want to be but cant boot at in dual ddr mode)

It's all a bit random and hard to explain... Not being able to boot with the
2:3 divider at all with this ram (i could with my old ddr333) just adds to
the confusion and suggests an incompatability to me.

Hopefully you can see what i'm getting at now?

Check out this link to see what the ram is capable of!

http://www.vr-zone.com/reviews/TwinMOS/PC3700-3200/page4.htm

Also if you look at some P4 2.4 reviews you will find that most ppl can at
least get it to boot past 3.2 (in dual ddr mode i assume).

Thanks, Jesse
 
Woops

In single channel mode it's 100% stable at 175MHz fsb, using a
2:3 mem ratio, 2.75v and low memory lats of 2:2:2:5.

should read '275MHz fsb' (still not used to these crasy fsb's :-P)

-Jesse
 
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