Why won't these 3 identical memory sticks run at 400mhz?

Computer Forum CPU, Motherboards and Memory
1

Part number on all the sticks is VS512MB400. For some reason, #2 has a second timing table but they all have a compatible one for 400mhz… but I can’t make it boot showing higher than 333mhz.

Board is an Asus K8N with an AMD Athlon XP 64 3100+

Ive tried configuring the memory to auto in BIOS, and it goes to 200mhz. When I set the clock, CAS# Latency, RAS# to CAS# and RAS# precharge to 200mhz, 2.5, 3, 3, 8 respectively, it only shows 333. Why is that?

Heres the weird part: Without the third stick in there it will do 400mhz

http://web.triggz.org/~triggz/cpuz.jpg

2

Have you got four slots?
Try and run only two in slots 1 and 3.
Then try and run two in slots 1 and 2.

Maybe the whole thing has something to do with the Dual Channel operation?

3

Big B

There’s a known issue with the Athlon64 design where you can have some trouble running 4 sticks at 400MHz. You may be able to go into BIOS and set it up at DDR400 speeds manually. Just keep that in mind as you might have trouble booting or with stability, which can happen when forcing the option.

Source

although i’ve not hear of any problems with 3 stick @ 400Mhz

4

For some reason, sticks 1 &2 will operate in any DIMM at 400mhz. Sticks 1 & 3 or 2 & 3 will clock down to 333 though. Something about the third stick somehow, even though its identical to #1.

I have another stick of Kingston KVR400 512mb, and a stick of Adata 400mhz 512mb and I can not combine any of the 3 to get 400mhz.

These is all single channel memory DDR400

5

[QUOTE=sabashuali]
Maybe the whole thing has something to do with the Dual Channel operation?
[/QUOTE]

multiple single channel RAM automatically becomes dual channel when they are installed with other single channel RAM in a mobo that supports dual channel RAM

BTW: sorry, i should have added that onto my previous post