[whywontitjustwork]

ok heres my latest issue, my computer had 512mb PC3200 CAS 3 ram which runs at 400mhz, so i went ant bought another 512 stick, but this one was cas 2.5 when i tried to run them both together it ran them both at 2.5 and lowered teh memry clock to 333! so i went out and got another stick of the exact same 2.5 pc3200 but it still runs at 333! whifh kills roghly 600mb/s of bandwith on the ram, which simply wont do! Oddly enough if i try to run just a single one of thoes sticks it runs at 400 with CAS 3, what is going on?? please help fast if this doesnt work i gotta return it tomorow!

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i would just rip out the whole RAM system and put in a new 4GB dual RAM

[wakedemons3]

i would just rip out the whole RAM system and put in a new 4GB dual RAM

[whywontitjustwork]

Well this bord only supports 2gigs, plus i dont have the money to buy a stick that size, anyways i dont know why it does this, why would it lower the memory clock to 333 when i put it up to a gig of CAS 2.5? and why does a single stick of it run at 400mhz CAS 3? it makes no sense, [bleep] thing should just work right

[Alex_Harris]

Have a look at the board specs. I have seen many times a board will support 400 Mhz ram if it is say less than a 1Gig, but as soon as you put a it 1Gig+ it will only support it at the slower speed.

[Verst]

Related issue: when MB set to BYSPD when i lower the frequency the latencies also get lower. Anybody know why?
Maybe that's the case here. Computer wants to run both sticks at CAS2.5 but can't achieve that at 400MHz so he automatically lowers the frequency. If it means that much try manually setting the frequency to 400...

[whywontitjustwork]

Yea thats what i think it is, it probably cant support CAS 2.5 @ 400mhz, ive looked through the bios but all i can do is limit the frequency not set it, so it still runs at what it wants too, oh well i guess i gotta go hunt down a stick of CAS 3 and try that out. Thanks for your help guys.

[Samm]

Do you have an Athlon 64 (socket 754) processor?

[whywontitjustwork]

Yep

[Doby]

What motherboard?

[Samm]

Athlon 64 & Athlon 64 FX processors have the memory controller built into them, unlike all other system where the memory controller is part of the motherboard.

The Athlon 64 (not the FX series) have a major restriction in that they cannot support 2 double sided RAM modules with a 200MHz clock (ie DDR400). They only support one DDR400 (double sided). To support more than one module, they have to be either single sided DDR400 modules (which are hard to get hold of) or double sided modules running at 333MHz max.

This problem doesn't exist with the 64FX series.