Question Is it O.K. to use 2 diff. sizes of RAM sticks?

ringtail

Golden Member
Mar 10, 2012
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Recieved an old Dell Inspiron with mismatched RAM stick sizes:
Slot 'DIMM_B' has 4096 MB
Slot 'DIMM_A' has 8192 MB.

Is having mismatched sizes like that O.K.?
Unless mismatched RAM sizes causes problems then I'd rather not buy old RAM for such an old slow computer.
 

VirtualLarry

No Lifer
Aug 25, 2001
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Ever since the Intel i865G / i865PE chipset for Pentium IV that utilized DDR memory in dual-channel, Intel has supported something that they call "Flex Memory Access", which means that each DIMM channel can be filled with un-even / non-matching RAM capacities per DIMM. Although one should defer to the mobo manual to determine which DIMM per channel to populate first, due to the DRAM bus wiring topology of the mobo.
 
Jul 27, 2020
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igor_kavinski
What can be concluded from this result of the test you suggested?
Bandwidth seems to be half of what it should be. If you want to upgrade the RAM, you may want to get a 16GB RAM kit so both sticks are identical. Can't say for sure if that will increase speed. Could be the CPU's memory controller. Try running the test with the laptop plugged in with the power adapter and power plan set to High Performance.