Difference between Singled and Double sided kingston ram?

Hi guys i have a kingston 512mb ddr1 doublesided 400mhz ram tiawan assembled and have just bought another 512mb ram but it is singlesided i.e it has chips only on one side and are of hinex company chinese assembled is there any difference in performance or will both give same performance? my shopkeeper also have ddr1 400mhz of kingston brand which has samsung chips double sided china assembled..