It has been surmised that I need to upgrade my memory to possibly alleviate some weird experiences I'm having with Sonar. So, I want to upgrade from 4 to 8 GB. However, the memory I installed originally is not available any more. I can find PC2 6400 RAM still, but not in the same timing as I currently have, which is 5-4-4. How important is it to have the exact same timing on the add on memory? Options I'm finding now are 4-4-4-15, 5-5-5-15, and 6-6-6-15. If it's OK to mix, which would be the best option? Thanks.

i reckon it will cause instability issues that, what about the voltages, are they different, if so, then give it a miss, could fry the lower voltage ram that

Found the voltage on the OCZ website. So, you're saying if the voltage is the same, I should be OK? The motherboard manual does indicate there can be two pairs of RAM installed with different capacity, brand, speed and chips per pair.  

Mark

do you know the brand and model of the ram in your computer, try these http://www.belarc.com/free_download.html http://www.crucial.com/uk/systemscanner/ scan might tell you without opening your machine up

Always use matched RAM. That means buy it at the same time and the same type and from the same maker. Never mix and match. 

Even using RAM from the same maker and type but bought at different times is risky. 

It is best to have the same manufacturer but you can safely have two different manufacturers if each set of ram is the same. Another words a pair of 4gb IBM and a pair of 4gb Kingston. The most important part is that they match. for example both are DDR3 SDRAM 1333 240-Pin Desktop Memory.
 
 
 
 

"for example both are DDR3 SDRAM 1333 240-Pin Desktop Memory. " if they both have different timings then there will be issues, same with voltage

I'm having difficulty finding anything with the same 2.1 voltage, much less the same timing. Might be a hopeless case for me, unless I just spring for all new 8GB of RAM, which I don't really want to do.

Mark

aye just get your self new ram, if you start mixing and matching, then have problems, you live and you learn

Mosvalve


It is best to have the same manufacturer but you can safely have two different manufacturers if each set of ram is the same. Another words a pair of 4gb IBM and a pair of 4gb Kingston. The most important part is that they match. for example both are DDR3 SDRAM 1333 240-Pin Desktop Memory.
 
 
 
 

Sorry, I don't agree. RAM timings are really in a range. They are not absolute. Thats why one ram module may over clock well and another wont with the same specs. Matched RAM gets by this because when bought together they very likely will have been made with the same run. Its highly unlikely RAM from two different makers will perform identically even with the same specs. Though they should but why take the chance?