When you talk about data (memory), it's 1024
When in general, Kilo is 1000. So, 10Kbps is 10*103 bps
@Arjun sir, what I think is, when it comes to storing the data then it should be 1024 Bytes(OS), and when it comes to Transfering of data from disk(DMA questions), Bandwidth (CN) then it is 1000 Bytes. Just observation.