qcmadness

you still need some backing benchmarks to prove that adding more memory channels does help

qcmadness

http://www.anandtech.com/show/45 ... ing-the-best-ddr3/8

引用:

I think we confirmed what we pretty much knew all along: Sandy Bridge's improved memory controller has all but eliminated the need for extreme memory bandwidth, at least for this architecture. It's only when you get down to DDR3-1333 that you see a minor performance penalty. The sweet spot appears to be at DDR3-1600, where you will see a minor performance increase over DDR3-1333 with only a slight increase in cost. The performance increase gained by going up to DDR3-1866 or DDR3-2133 isn't nearly as pronounced.

SB nowhere requires another 20GB/s memory bandwidth when ~20GB/s is enough.

qcmadness

引用:

原帖由 Henry 於 2011-8-17 04:48 發表

I have already read the review long time ago.
As I said, depends on arch, OPs performance, cores, also the tasks.
If CPU cannot feed the RAM bandwidth, CPU is the bottleneck.
If CPU need to wait for  ...

1. you still have not shown any tasks which scales well with memory bandwidth
2. SB-E for desktop only 4 and 6 oores. 8 cores is your IMAGINARY product
3. http://www.anandtech.com/bench/P ... 5&i=221.222.223 is this clear enough?

qcmadness

引用:

原帖由 Henry 於 2011-8-17 05:39 發表

1. I am sorry I cannot show this moment, but does not scale well =/= does not scale. (Something similar should be the first test in your link 3)
2. 8 core is still available in LGA2011 form, and I ca ...

1. of course it scales, but is the scaling meaningful is another question
2. i don't think so, server socket for 4 qpi connections is different
3. decompression / compression is particularly bandwidth sensitive

qcmadness

Edit: both server and desktop versions of SB-E have LGA 2011
but compatibility is unknown and only 2 QPI lanes are available...