With quad channel memory, can I use two sets of different capacity (like 4x1 GB + 4x2 GB)?

Question

My motherboard has quad channel memory compatibility. There are 8 memory slots in all:

4 slots are black
the other 4 slots are white.

I currently have 4 memory modules of 1 GB each in the 4 white slots. That leaves me with 4 free memory slots.

My question is: can I put 4 memory modules of 2 GB each in the 4 remaining slots or do I have to use modules of 1 GB all over?

FYI here is the output of lshw:

alpha
    description: Ordinateur Tour
    produit: Precision WorkStation 690 
     *-cpu:0
          description: CPU
          produit: Intel(R) Xeon(R) CPU           X5355  @ 2.66GHz

     *-memory
          description: Mémoire Système
          identifiant matériel: 1000
          emplacement: Carte mère
          taille: 4GiB
        *-bank:0
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns)
             produit: HYMP512F72CP8N3-Y5
             fabriquant: Hynix Semiconductor (Hyundai Electronics)
             identifiant matériel: 0
             numéro de série: 56737501
             emplacement: DIMM 1
             taille: 1GiB
             bits: 64 bits
             horloge: 667MHz (1.5ns)
        *-bank:1
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns)
             produit: HYMP512F72CP8N3-Y5
             fabriquant: Hynix Semiconductor (Hyundai Electronics)
             identifiant matériel: 1
             numéro de série: 48115124
             emplacement: DIMM 2
             taille: 1GiB
             bits: 64 bits
             horloge: 667MHz (1.5ns)
        *-bank:2
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns)
             produit: HYMP512F72CP8N3-Y5
             fabriquant: Hynix Semiconductor (Hyundai Electronics)
             identifiant matériel: 2
             numéro de série: 48115523
             emplacement: DIMM 3
             taille: 1GiB
             bits: 64 bits
             horloge: 667MHz (1.5ns)
        *-bank:3
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns)
             produit: HYMP512F72CP8N3-Y5
             fabriquant: Hynix Semiconductor (Hyundai Electronics)
             identifiant matériel: 3
             numéro de série: 48115424
             emplacement: DIMM 4
             taille: 1GiB
             bits: 64 bits
             horloge: 667MHz (1.5ns)
        *-bank:4
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns) [vide]
             fabriquant: FFFFFFFFFFFF
             identifiant matériel: 4
             numéro de série: FFFFFFFF
             emplacement: DIMM 5
             bits: 64 bits
             horloge: 667MHz (1.5ns)
        *-bank:5
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns) [vide]
             fabriquant: FFFFFFFFFFFF
             identifiant matériel: 5
             numéro de série: FFFFFFFF
             emplacement: DIMM 6
             bits: 64 bits
             horloge: 667MHz (1.5ns)
        *-bank:6
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns) [vide]
             fabriquant: FFFFFFFFFFFF
             identifiant matériel: 6
             numéro de série: FFFFFFFF
             emplacement: DIMM 7
             bits: 64 bits
             horloge: 667MHz (1.5ns)
        *-bank:7
             description: FB-DIMM DDR2 FB-DIMM Synchrone 667 MHz (1,5 ns) [vide]
             fabriquant: FFFFFFFFFFFF
             identifiant matériel: 7
             numéro de série: FFFFFFFF
             emplacement: DIMM 8
             bits: 64 bits
             horloge: 667MHz (1.5ns)
     *-pci:0
          description: Host bridge
          produit: 5000X Chipset Memory Controller Hub
          fabriquant: Intel Corporation
          identifiant matériel: 100
          information bus: pci@0000:00:00.0
          version: 12
          bits: 32 bits
          horloge: 33MHz

score 1 · Answer 1 · answered Feb 24 '13 at 11:45

It was a bit tricky finding information since LSHW was in french. However the usermanual for the model seems to cover it

"For optimal performance fully buffered DIMMs (FBDs) should be installed in matched sets of four. This enables quad-channel operation and provides the highest memory bandwidth. The sets of four must be matched in size, rank, and organization. This information can normally be found on the FBD label. For example, the label of each FBD in a set of four might read: 1G 2R x8, in which 1G represents the size of the memory module, 2R represents the number of ranks, and x8 represents the organization."

This means you should be able to install a set of 4 memory modules of 2gb with no issue alongside your current ram. You can find the manuals here

With quad channel memory, can I use two sets of different capacity (like 4x1 GB + 4x2 GB)?

1 Answers1