noob question concerning fsb/ddr ratio

athlon xp 2500+ barton (333MHz)
kingston valueram pc3200 256MB x2 (400MHz)

what is known to perform faster with that setup: 333/400MHz or 333/333MHz? Am I right assuming that 333/333MHz is sync mode and the other isn't?
And if I rather set the mobo to read RAM specs in the SPD, will the setup choose to run it in sync mode (333MHz), or 400MHz instead?
This is not an overclocked pc.
Thanks a lot!

..if anyone uses Asus AMD mainboards please have a look of my other thread.

my understanding with the amd stuff is to run everything 1-1. intel is better at running async ratios..

bump

Dont run it out of sync. 333/333 would be faster than 333/400.