Adding to an older system - should i mix these?

[No-One]

My sisters old system is an Athlon XP system. The board has 3 memory slots. The system has 2 sticks of 256 meg Crucial DDR 333mhz cl2.5 pc 2700. I've just come into possesion of 2 sticks of Corsair 512meg 400mhz cl2 xms 3200. Would it be best to just put the 2 corsair sticks in and get rid of the older crucial ones?

 

[furnace]

I doubt it has Dual Channel, does it..? Even so though, I'd put in the two 512's and one 256. If it does have dual channel, make sure you put the two 512's in the dual channel slots.

 

[Cob]

Yeah some Socket A boards had dual-channel.

If you keep a PC2700 stick in then all the sticks will run at 333mhz and CAS 2.5.

I would still try it with a PC2700 stick and see how it runs.