Dead memory slot and performance question

hi i have a core i7 920 sysytem with 3x2gb sticks of ram. the first two slots on the motherboard have somehow died iv tested all memory one by one ect. so here is my quistion

: if i have 2 sticks in 2 slots they'll run dual channle right, so with that, would it be better to leave the 3rd stick of ram out, or put it in the end slot making that stick only run in single channle mode. i cant afford another motherboard for awhile and no warranty so wich would be the better option for performance?

thanks
winter

Ususally slots that run in dual are numbered alternately,
ram in slots 1+3 or 2+4 will run at dual channel, any other way such as 1+2,1+4 etc will not give you the dual channel benefit,
post Mobo details and detail which two slots are defective,
P.S. a three stick kit will never run in dual channel anyway, its single or triple
Moto

its a X58 motherboard i know i will run in dual channle mode, somewheres theres even a chart from having 2 sticks and then 3stick double or tripple channle. but thats not my question my question was since 2 out of 6 memory slots are bad that leaves me working with the last 4 slots. 2 sticks are in there now so its running in dual channle mode. butif i ad a 3rd stick into the last slot that stick would run in single channle mode. will that slot the pc down or would it be good to put it in the last slot even though that stick would run in single channle mode

(rember the first 2 are dead so no tripple chanle)

they are 3x2gb sticks of gskill 1600mhz

bump, any ideas?

No i hav'nt run benchmarks yet but will probably switch to x64bit indows just to try it and bench it, but i was hoping to have an idea before hand. and Dadiggle the memory is GSkill cas 8 1600mhz ddr3