M6600 Memory Decision

I just bought an M6600 and have been studying my options for memory. Any of the processors can outrun memory access, so any increase in speed would matter.

Thoughts:
Memory options:
1. DDR3 PC3-10600 sodimm 16GB (2 x 8GB) CL=9 (1333 RAM)
2. DDR3 PC3-12800 sodimm 16GB (4 x 4GB) CL=9 (1600 RAM)
3. DDR3 PC3-12800 sodimm 16GB (2 x 8GB) CL=11 (1600 RAM)

- The difference in clock cycles is 20%
Going from 1 above to 2 above, would be ~20% improvement since they both have the same latency. (1600 / 1333) = 1.2 As long as you don't need over 16GB, this would be the fastest. There would not be a 20% real-world gain, but should be significant.

- For the 8GB 1600 sticks, the CL goes up to 11. That represents slightly more than a 20% loss. Thus, the 8GB 1600 CL=11 sticks should be a whisker slower than the 8GB 1333 CL=9 sticks. Therefore the 8GB 1600 sticks make no sense in any scenario.

What are your thoughts?

 

I am surprised to see that 1600mhz 8gb stick is available. Do you have any link? Cause as far as I am aware with the cpu architecture, it wont support 32gb at 1600mhz.

 

Oh Duh. I went to NewEgg to paste you the link, and couldn't find it. I'd bet I read it wrong. Looks like grounds for sending me out for a drug test.

 

i dont see any noticeable difference between 1333mhz and 1600mhz. Everything else would be a bottleneck. And the difference, will be minute at most.

Go for 16GB (2 x 8GB) for future upgradeability.

 

That has been my experience as well, although I've never worked with an M6600. I may do that.

Thanks

 

I found the link. 8GB 1600 Sticks It looks like a terrific stick with CAS 5, 6, 7, 8, 9. The only problem is the best price I've found on them is $215/stick. That would be $430 for 16GB and $860 for 32GB. If I could run at CAS 7, they would probably do as much good as a processor upgrade from my 2720QM to an XM, but it's also about the same price. LOL!

 

Thanks for the link. I am actually not surprised to see these. I think the precisions should be able to host them. Though I am not sure about any performance difference.

 

It's not a Precision problem. The chipset can handle the fastest laptop RAM available. The problem is how the mobile processor changes to handle RAM above 16 GB, and that is usually socket related. Memory limitations are always time limitations, not cycles, even though they are usually specified in cycles/CAS for clarity. Therefore, if you take 8GB sticks that can run at CAS 9 at 1600 or 1866, a profile with CAS 7 or CAS 5 at 1333 memory will deliver latencies equal to 1600 or 1866. The trick is, when you go from 4GB to 8GB sticks, things have to happen in half the time to maintain the same CAS, so 1600 8GB sticks are pricey, plus you need one that will accept profiles. I learned from Bokeh that he couldn't get away with mixing memory of slightly different models from Kingston, because when put together, they would ignore the profiles, and use the default.

 

Can't go wrong with Crucial.

http://www.crucial.com/store/listparts.aspx?model=Precision+M6600+(4+SODIMMs)