Memory question- 2.5G @ 333Mhz or 2G @ 400MHz

Just upgraded the memory in my Dell 4600. Had 512Megs of memorry, and added two 1G chips. However, the older memory chips were 333Mhz chips, so now they are all operating at 333MHz.

Would I see better performance if I just pulled the two older 333Mhz chips out and ran just 2G at 400Mhz?

Thanks.