OMEN 870-120st memory configuration can you have 2 pairs of 2 of different sized memory modules

[MikeUX]

I have  purchased a HP OMEN 870-120st CTO with 16GB RAM, and want to add memory. 

A really nice thing is there are 2 pairs (4 slots) of Dual Channel Memory slots.  I understand that you cannot mix memory, they must be paired the same.  I am assuming that this means the memory slot pairs need to be the same?

I have ordered this installed memory configuration, hoping that I would be able to purchase additional memory at a later date -

• 16 GB DDR4-2133 SDRAM (2 x 8 GB)

Can I mix pairs of memory?      

              Example:  16 GB DDR4-2133 SDRAM (2 x 8 GB)       +      32 GB DDR4-2133 SDRAM (2x16 GB)

Can I install 2 memory slots of - 32 GB DDR4-2133 SDRAM (2 x 16 GB) and keep the current 2 memory slots - 16 GB (2x8 GB) installed, and have a Total of48 GB of RAM? 

OR    do all memory modules need to match, same configuration example:  all must be  32 GB DDR4-2133 SDRAM(4x 8 GB) ?

Also, do all the memory modules need to be the same Brand and Part number for the memory sets If I were to just add 16 GB of additional memory for a total of 32 GB RAM?

Motherboard Description -

• Manufacturer name: Pegatron
• HP/Compaq name: Thimphu
• SSID: 2B4B

Memory Upgrade Information -

• Dual channel memory architecture
• Four DDR4 DIMM (288-pin) sockets
• Supports PC4-17000 (DDR4-2133)
• Supports 2 GB, 4 GB, 8 GB, and 16 GB DDR4 DIMMs
• Supports up to 4 GB on 32-bit systems

   note:

  32-bit systems cannot address a full 4.0 GB of memory.

• Supports up to 64 GB (unbuffered) on 64-bit computers

   note:

  Maximum memory shown reflects the capability of the hardware and can be limited further in the operating system.

[old_geekster]

@MikeUX, welcome to the forum.

It is always best to use the same brand of memory whenever possible because it will eliminate possible compatibility problems.  However, if you use the same brand in matched pairs, I don't believe you will have any problems.

Q: Can I mix pairs of memory?      
              Example:  16 GB DDR4-2133 SDRAM (2 x 8 GB)       +      32 GB DDR4-2133 SDRAM (2x16 GB)

Can I install 2 memory slots of - 32 GB DDR4-2133 SDRAM (2 x 16 GB) and keep the current 2 memory slots - 16 GB (2x8 GB) installed, and have a Total of48 GB of RAM?  

I couldn't find any information on how you should popultate the slots.  I do believe that as long as you install 2 x 8 and 2 x 16 it should be fine.

Please click the Thumbs up + button if I have helped you and click Accept as Solution if your problem is solved.

[MikeUX]

Thank you for your reply.  I had searched for answers that could be backed up by HP.   I do not feel comfortable purchasing memory, that might not work, or sortof work, sortof not work.  I had hoped that a HP employee would respong to my questions, or someone who has successfully done what I am looking to do.

I have purchased HP Products for some time now.  All of my Pc's, this OMEN, that ships 11/20 something,  and my HP Envy i7 Laptop, and printers have all been HP.  I am a Enterprise Systems Administrator, where I work, and all of my servers are HP (BL860c i4's, BL460c, and Proliant).  I believe that HP products are the best.   My hope is that a HP employee would respond to my questions.

What if I leave the HP memory that ships with the OMEN 16 GB (2x8) and then add -> 32 GB (2x16) Ripjaw RAM for a total of 24 GB RAM?  Or add -> 16 GB (2x8) Ripjaw RAM?

Thank you for your reply.  

[old_geekster · Accepted solution]

You are welcome.  Thank you for the additional information, @MikeUX.

This is a peer to peer help forum. The only presence that HP has on it are the Admins and the Mods. Otherwise, none of us works for HP.  With that said, I am comfortable telling you that I would not try to combine the gaming Ripjaw memory with the OEM memory.  Here is the memory that is recommended by Crucial Memory.  Their Ballistix memory has received good reviews.  You could contact their Tech Support to see if it would work if you combine it with the OEM memory.

If you want to increase the performance even more, you should consider adding a SSD.

[MikeUX]

Thanks for your answer, old_geekster.  I will take your advice and concider this Solved.  I appreciate your assistance.

[old_geekster]

You are welcome, @MikeUX.  I would be interested in hearing what you decided to do and how it worked.

[MikeUX]

I will do that old_geekster.  Thank you again.

[old_geekster]

You are welcome, @MikeUX.