390X ,cel 400 wont take pc-66 ram

[SaberX]

I have a 390X system here.It's running a celeron 400.
I thought wheres it's running a celeron 400Mhz i could use PC-66 ram.
But when i put in some pc-66 i get a message saying this system needs pc-100 ram inorder to run.

[pianowizard]

i get a message saying this system needs pc-100 ram inorder to run.

Yep, that's also what the Twbook says.

Some 400MHz Celeron processors actually have 100MHz bus speed. The 390X probably uses one of those.

[SaberX]

well i ran CPU-ID on it and it comes up Celeron 400Mhz , 66Mhz FSB.
So the system is running at 66Mhz bus.But still cant use the pc-66 ram.
Strange.