How much RAM for dual Xeon e5-2670 v3

jmax2

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Dec 4, 2015
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At work we have render server with dual e5-2670 v3 and only 16GB (2*8) RAM, I've read on the internet that is recommended at least 2GB RAM per core so that means 48GB since this processor has 12 physical cores. The average usage of ram when rendering is 5GB so do we really need 48GB, Im asking this because in some cases the rendering seems slow so maybe there is a some kind of bottleneck with the ram.

I need to know how the multiple cores use the memory, do they have to wait a lot to get access to memory, since one cpu with 12 cores only has one ram stick with 8GB.
 

kanewolf

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If you have two CPU sockets, you should install RAM in the slots for each socket. The E5-2xxx V3 CPUs have quad channel memory controllers, they are most efficient with multiples of 4 DIMMs / socket. For maximum performance you should install ram in multiples of 8. So 8 x 4GB or 32GB is the minimum recommended configuration to use all the available performance the architecture has.

Each of those CPU sockets has 12 cores and hyperthreading. You could have 48 threads executing.
 

jmax2

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I've run some benchmarks for the memory and it only uses half the bandwidth around 32GB/s. Would it make a lot of difference in real tests if it was using the whole bandwidth?