This should be an easy one for you platfrom gurus out there. Basically, I am wondering if I will have better overclocking bang for my buck on the X79 platform in general with 32GB ram if using 8x4GB DIMMS vs 4x8GB DIMMs?
Pros for 8x4GB: 8GB modules cost a premium to 4GB ones. Furthermore, the tighter timings and higher clock speeds seem to be harder to achieve with larger DIMMs, and therefore cost an even greater premium if even available.
Pros for 4x8GB: On the flip side, is it not easier on the CPU memory controller to only see 4 DIMMs (vs 8 ) and therefore would I not likely achieve higher clocks (albeit at the cost of lower FSB or equivalent)? Due to the quad channel memory interface, there does not seem to be much benefit in going with DDR3 faster than 1600mhz (PC3-12800)in real world applications and most benchmarks, so worrying about finding affordable high-speed 8GB DIMMs may not be such an issue (though 4GB DIMMs are still a bit cheaper, even those rated at somewhat higher speeds). Are timings (ie, CAS 9 vs CAS 10) also not worth worrying too much about? 8GB DIMMs also allow to upgrade to 64GB in future if going with an 8-module board - but I don't see that ever happening. The only reason I'm considering 32GB over 16GB is so that I can play around a bit with ram disk configs. And if I go with 8GB DIMMs, I can always save a few bucks up front by going with a cheaper 4 module board.
So, as a rule, do I go with 32 GB on X79, should I go 4x8GB or 8GBx4 to get the most overclockable/stable system?
BTW, I'm thinking of either going with an Asrock X79 Extreme4 (4 slots) or Extreme6 (8 slots), as these seem to be great overclocking boards and have a pretty decent feature set for the money. At least in the US. In Canada, for some reason, Asrock is just as expensive as Asus (as much as 50% more for the same board in Canada as in the US). This is bizarre as the price difference between countries for most computer components is negligible, but I digress...