Memory recommendation for ASUS Z8NA-D6?

[hasu]

I am upgrading my server (ASUS Z8NA-D6, 2 x X5672/LGA1366 ) to 32GB ECC ram. Should I go for Registered or Unbuffered? I run many VMs on this host. Which one will have better compatibility with newer motherboards and CPU?

Thanks!

Edit: I found some very useful information here
http://en.community.dell.com/techcenter/high-performance-computing/w/wiki/2272

 

[CiPHER]

Socket1366 still has triple channel memory support. So install per 3 modules. Then the maximum is 24GiB not 32GiB for that you needed 2x4 instead of 2x3 slots.

The board can only go over 24GiB when using Registered memory. Unbuffered (= not registered) memory is usually better because of memory timings/latency. But you cannot populate the server with too much UDIMM. The latest boards support up to 64GiB UDIMM as far as i know, and require RDIMM above that. Check your motherboard's manual. This is what i found about yours:

Total Slots : 6 (3-channel per CPU, 3 DIMM per CPU)
Capacity : Maximum up to 96GB RDIMM/Maximum up to 24GB UDIMM
Memory Type :
DDR3 RDIMM*
DDR3 UDIMM*
Memory Size :
16GB, 8GB, 4GB, 2GB, 1GB RDIMM
4GB, 2GB, 1GB UDIMM

 

[hasu]

Socket1366 still has triple channel memory support. So install per 3 modules. Then the maximum is 24GiB not 32GiB for that you needed 2x4 instead of 2x3 slots.

The board can only go over 24GiB when using Registered memory. Unbuffered (= not registered) memory is usually better because of memory timings/latency. But you cannot populate the server with too much UDIMM. The latest boards support up to 64GiB UDIMM as far as i know, and require RDIMM above that. Check your motherboard's manual. This is what i found about yours:

Thanks for the reply!

I was thinking 4x8GB. 32GB should be sufficient for my application, but if triple channel makes good improvement then may be I should shoot for 6x8GB. I read that RDIMMs are needed if you have large amounts of memory, and was wondering what would be considered as large amount? Do I need RDIMM for more than 24GB or 32GB?

Edit: I just noticed in your reply that 8GB should be RDIMM

Does DDR3-RDIMM have compatibility with modern server systems (Post LGA1366)?

 

[CiPHER]

The manual page i quoted says it all. If you want UDIMM (Unbuffered) then maximum 4GiB modules can be used. 6*4=24GiB RAM. When using RDIMM (Registered) then the maximum goes up to 96GiB (6* 16GiB).