Basically I want to know whether or not having one type of ram in pair and then a different, newer model in pair alongside it would impact the overall system. I can easily purchase a new set of 4x4 or 2x8 and stash the old sticks. Of course, having all the ram a better performing model would be better, but would like to know how this works. Thanks.
More about :ram 2x4 sticks sold anymore buying 2x4 make specs impact system
It is likely that adding two newer versions with different specs will work - just not optimally. If they are nearly compatible - just different CAS speeds and such - it may be that the faster ram will slow down to meet the slower chips.
It may also turn out that they are not compatible at all. I would suggest - if this is an option - that you buy the 2x4GB you want - and add it to your system If it works - great - check the timings and see what the situation is.
If it doesn't work - ok - take out the slow old RAM - use the faster ram for the time - and buy more sticks in line with the new RAM. Sell the old stuff on e-bay.
Avarice has hit the nail on the head. Best Answer material for sure.
Yes, it will function. As long as they are both standard DDR3 (or 2 if that's what you have) they should function at the settings of whichever one has the loosest (slowest) defaults. However, if you want to get the most extreme possible performance, there are reasons that memory is sold in kits of 4 instead of picking up 4 individual pieces. One of those reasons is the advertising power, of course. But running 4 modules in dual channel config calls for some slack and some modules are designed to run that way.