Combining latency across dual channels.
Combining latency across dual channels.
Hey, so this is for the RAM upgrade for my friend's Mac Pro from 2013. It has a small opening bay for the ram slots which seems completely impossible because it's Apple, right, user-friendly? Apple? Anyway, i t's old and all I know is it has 8Gb of DDR3 RAM at 1600Mhz. So he plays Minecraft, a CPU and memory crunching game. It already has 2x4Gb and can still carry 2 other modules. Options are to take 1x8Gb, 1x4Gb, 2x2Gb or 2x4Gb. I know DualChannel is better, especially on older computers. Now here is a tricky question, so we have the existing 2x4Gb DualChannel at 1600Mhz of which I don't know the Cas latency. Now, because we want to make a second DualChannel thing, can we take any frequency and timings and will it affect the other DualChannel (the already existing one) like lowering the frequency or getting the timings to rise or will the 2 DualChannel run at their given speeds? Oh and also, is a 8gb dump to 16 worth or should he take only 4 to get 12gb?
It's not designed for upgrades, so the outcome when mismatched SPD profiles appear isn't clear. However, you might find the codes on the label of your current memory modules helpful. Consider adding 8GB; with just 4GB it would likely be dual channel at 8GB or single channel at 4GB, facing similar uncertainties about CAS latency.
You've had some time with this setup and haven't encountered any problems. The details you shared suggest a stable performance over six years, especially since you didn't adjust the original RAM's clock speed. Others might have different results depending on their configurations.