one cpu vs dual cpu memory config

[ary3d]

I will have the same performance if I compare 1 cpu socket with 4 ram slot ( 4x8gb) to a dual cpu socket with 8 ram slot ( 8x4gb) both machines will had 32gb, is for multicore rendering task

thanks

David

 

[kanewolf]

Usually dual sockets will have more memory bandwidth. There are specific comparesons where single could be equal.

 

[ary3d]

thanks for you comment, I need to know if a single cpu with 32gb of ram will perfom equal to a dual socket with the same amount, let say, on render time I consume 28gb of ram, one processor will use all, but what about two processors doing the same render, ram is need it in equals amount for each prossesor to render properly?

 

[kanewolf]

thanks for you comment, I need to know if a single cpu with 32gb of ram will perfom equal to a dual socket with the same amount, let say, on render time I consume 28gb of ram, one processor will use all, but what about two processors doing the same render, ram is need it in equals amount for each prossesor to render properly?

It depends on the CPUs in the comparison. A single i7-6950K might outperform two E5603 processors. There is no BLANKET statement. If you pick specific CPUs you are trying to compare then a more specific answer can be given.

 

[ary3d]

for performance I only want to know about ram, let supouse that I have:

1 cpu 8c, 32gb of ram 4 slot, sticks of 8gb
vs
2 cpu 2x4c 32gb of ram 8 slot, sticks of 4gb

I guess I want to know about the dedicated slot for each cpu, this mean I have only 16gb of ram for each cpu? against 1 cpu having 32gb?

 

[alceryes]

Memory performance will depend on what you are doing. As @kanewolf said, there's no blanket statement here.
What application do you want the best performance in?

 

[ary3d]

3d rendering, full multicore, raytrace calculations ( maya, max, lightwave, cinema 4d, blender, etc)

 

[kanewolf]

for performance I only want to know about ram, let supouse that I have:

1 cpu 8c, 32gb of ram 4 slot, sticks of 8gb
vs
2 cpu 2x4c 32gb of ram 8 slot, sticks of 4gb

I guess I want to know about the dedicated slot for each cpu, this mean I have only 16gb of ram for each cpu? against 1 cpu having 32gb?

The example I gave you with an i7 vs to Xeon E5xxx CPUs probably has the i7 winning. It has faster RAM and faster clock speed. An E5-2xxx V5 would be about the same. Your generic statements don't provide any additional info compared to what you stated in your first post.

 

[ary3d]

I only wanted to know if there is a penalty for distribute the same amount of memory on two cpu, I don't want to make a accurate comparison, since dual socket board has dedicated memory slot for each procesor, so I got the idea if it was the same to give 16gb for each cpu, than 32gb for a single cpu

Thanks for all the answers!

 

[kanewolf]

Dual sockets can have a memory access penanlty if data is physically in DIMMs associated with socket 2 is needed by socket 1 then the data has to be retreived by socket 2 and transferred over the dedicated bus between the two cpus. This is slower than data directly from socket 1. There are techniques used in high performance computing to "pin" the data near to a set of cores. In VERY large memory computers (multiple TB RAM) the delays associated with "bad" memory layout can be signicant.

 

[ary3d]

thanks for the knowledge Kanewolf, that was the type of answer I was looking for!