P4P800 Dual DDR Issue [Revised Question]

J

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 275MHz fsb, using a
4:5 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.


In summary:
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)

PS freq's in brackets beside ratios are what the mobo lists the ratio as. ie
i choose 266mhz for 2:3.

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
 
J

Jesse

Hi, another quick revision... --

where i said:
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)

250 * 12 = 3072MHz (3:2 mem, stable - why am i stuck at this?)
should read:
250 * 12 = 3072MHz (4:5 dual ddr mem, stable - why am i stuck at this?)

-Jesse
 

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