Use the specified slots for each RAM kit as indicated by your motherboard or system requirements.
Use the specified slots for each RAM kit as indicated by your motherboard or system requirements.
I have an AM4 system that had 16GB (2x8) of RAM, and I want to upgrade it to 32GB. Because of RAM prices recently I decided to buy another 2x8 kit and use all 4 slots instead of 2x16. And what I'm wondering now is, should the kits go in slots 1+3 and 2+4 or 1+2 and 3+4? From what I understand, the reason why 2 sticks are usually put in slots 2+4 is to use separate channels for performance. But when there are 4 sticks, would it be more stable if the same kit is completely on the same channel (i.e. 1+2 and 3+4), or if the kits are split between channels (i.e. 1+3 and 2+4)? For context, the old kit is 3600 CL16 and the new one 3866 CL18, so I'm hoping I could get them both to run at 3600 CL16 (dropping the clock on the new kit might be enough to allow me to tighten up the timings to match the old kit). And the PC is not actually mine, it's a friend's, so I'd like to improve the chances of success from the start, so that I don't have to talk him through memory tuning on the phone or fix his PC across multiple visits if he has stability issues.
Sticks from identical kits must reside in matching memory channels. However, the optimal solution is to prevent using separate memory sets for different memory groups.
For maximum reliability, use the kits together in matching memory lanes (1+2 and 3+4). This approach increases success odds, even though the gap on AMD systems is small in real-world use.
Here’s a clearer version of your message:
I understand what you’re saying. Back then, a 32GB DDR4 kit cost around 60 euros, and that would have been fine. However, AI changed things, and now I’m stuck answering these confusing questions about configurations I don’t fully grasp, even though I’ve built PCs for over ten years. It’s frustrating because it used to be easy.
I explored the topic and realized it isn't ideal for DDR4 setups. Each kit should stay within its designated range—A1-B1 or A2-B2. This advice comes from several guides, including the one you shared on XDA Developers. For DDR5, the recommendations differ, but mixed configurations remain risky.
Thank you for the piece. This was precisely what I aimed to prevent, as evaluating RAM stability isn't quick, and performing tests in both directions increases the overall time needed.
The article might be a bit confusing. Risky doesn’t capture the situation well—you won’t harm anything. In the worst scenario, you might not be able to start up at all and could need some manual adjustments. Most often it’s a normal situation where performance drops because you’re forcing your memory controller to work harder. It’s not necessarily a RAM problem but rather related to running two DIMMs per channel.