hey guys, I made a new PC 2 years ago and only got 2x2gb of ram because the price was double what it is now..... So now I was thinking that I should buy some more ram while the prices are low. I was just wondering if you can mix ram, like latency, brand etc...
You cannot mix ram, it will cause numerous issues as well as not run in dual channel mode. When you turn your PC off everything in RAM gets erased. So no, it will not effect anything to replace RAM.
It is best to buy the kits at the same time and not to try and add memory that is the supposed same brand/model because there could be tiny differences such as timing and voltage that may cause issues. It is recommended to get all tested kits.
There really is no issue theoretically with mixing RAM as long as it is of the same type. If you try and mix brands, DDR30133 w/ DDR3-1600 or CAS 7 w/ CAS 9, you generally going to have to run it at the lower speed to make it run .... even then you may have to relax timings just a bit w/ 4 modules.
In practice however, it's always best to use the exact same modules....if nothing else, it's going to make that tech support call a lot easier. If the same module is available, it's best to gran it. I have had success most of the times mixing brands but I try and avoid it as if you call TS, it's always going to be the other guy's fault.
I only but other brands when the existing RAM is no longer available..... most times I have gotten away with it. Could be just luck of the draw but the times I have been unsuccessful both involved adding new Gskill RAM to sit along side existing Corsair or Mushkin sets. When upgrading two machines, one with Corsair and one with Mushkin ..... both of which didn't make compatible modules anymore, I bought new Gskills for both boxes.....no success w/ either but I was able to marry the Mushkins and Corsairs in one box and stick the 4 Gskills in another.
I would not add the CXAS 7's to the CAS 9's as they would be forced to run at CAS 9 speeds. Since the original RAM modules are still available for purchase, I don't shy you wouldn't consider just buying another pair.
Keep in mind that when overclocking, it's harder to get those highest OC's w/ 4 modules than 2 modules.
I've never had a problem mixing various brands of ram so long as the CAS latency and memory speed are the same and I've done this on pretty much every PC I've ever owned. In my main PC I currently have 2.5GB of ram because I had 2x256MB sitting around so I stuck it in.
Even if you have different speeds and CAS latencies it could still work with a good motherboard that allows you to adjust memory settings, but the odds of it working are much lower.
There is really no reason to go to 1066 cas 7 when you previously had 1600 cas 9. I'd just buy more of the same for cheaper rather than throwing away what you already have.