Is dual-channel RAM operation independent for each bank?
- by user553702
For dual-channel usage of DDR3 SDRAM, what happens if one bank has DIMMs in both channels but the other bank has only one DIMM in one channel? Will the bank with the paired DIMMs operate at the dual-channel rate while the bank with the unpaired DIMM operates at the single-channel rate? Or does having a bank with an unpaired DIMM force all of the RAM to operate as single-channel?
For example, if I initially have only one bank populated with paired 4GB sticks operating as dual-channel, what happens if I then add a single 8GB stick to the other channel leaving the last DIMM slot empty? Will this stop the 4GB sticks from being dual-channel?
In addition, what happens if each bank has DIMMs of different clock speeds? Does each dual-channel bank operate at an independent speed, or does all of the RAM operate at the slowest DIMM's speed?
For example, in the above scenario, what would happen if the 8GB stick I added is slower than the original 4GB sticks in the other bank? Will the (paired) 4GB sticks then operate at a slower speed than before?