Hello, a quick question for the experts.
I have a used ROG zenith extreme that I bought used, no warranty, but super cheap. A gamble basically. It works almost perfectly, and is overkill for my uses, but I love it.
However Through trial and error, I have found that memory bank C (both slots) will not work, and neither will the nearest slot in to the CPU in bank D. Bank A and Bank B both seem to work just fine.
This limitation is not a major downfall for me, and I compute just fine with two sticks of ram.
My question, because I am a constant tinkerer on my computer, is: Are there any drawbacks from having a triple channel set up? I could get one more stick of ram and have 48 GB of ram. Not that I need it, but it would scratch that itch I have. But only if that isn’t the stupidest idea on the planet. The one thing I could even hypothesize as a negative was that maybe one set of cores that interfaced directly with one bank and the other set interfacing directly with the other bank might cause some problems having different amounts of capacity or throughput?
Thanks in advance.
I would think no, just that you are limiting the memory bandwidth due to not using the native 4 channel memory support.
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CPUs can’t swtich so dynamically the memory channels. If a CPU has quad-channel memoery support, if you don’t have access to 1/4 of the slots you’ll run some sticks in dual-channel and some in single-channel mode.
With that cleared out the consideration you made about memory is valid because only 2 dies out of the four max available in a Threadripper CPU are connected directly to memory. So you’ll have one DIE connected to dual-channel memory and one connected to single-channel memory. I don’t know the impact of an unbalanced memory configuration on Threadripper, but I don’t think it would hurt your performance that much. But I’d be really cautious with those kind of memory configurations. In general I’ve only seen and had issues running RAM sticks not in pairs. I don’t know if a Threadripper chip that’s using two dual-channel controllers would fair better on the long run, but I don’t suggest you doing it.
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Yeah, at the time I built the system I knew only running 2 sticks would limit my bandwidth. But then I realized that the system I was using only had two channels also. So at the time that was a push. and the Mobo was at such a great price, even the gamble was worth it. I kind of was hoping that the only thing wrong was that whoever had it last just didn’t update the bios or something.
Anyhow, I have chosen to get the 3rd stick of ram, and Memtest86 shows I have more bandwidth now. We shall see if I encounter any hickups.
The one thing I think doesn’t matter is that the threadripper is 4 separate channels so each stick, if I use 1, 2, 3, or 4 has a full channel. But I am no expert.
I do think you are correct that having on die set run on dual, and one die set on single channel could potentially cause problems though.
I have elected to get the 3rd stick, and we shall see if there are any problems. I do thank you for your input though.
ON TO EXPERIMENTATION and TESTING!
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