It has logic. Cryptonight uses 2MB L3 cache per core. So if your CPU has 16MB, that means it can utilize 8 cores. The rest of the cores can be used for something else. From what I have seen ROI does not care how much L3 cache you have, as longs as your clock speed is good. But I highly doubt that power usage iwll remain the same. Will try it out myself soon.
You would be shocked. I have my rig on a power tracker and power don't go up any. However thread setting is the key. I found leaving 2mb free the best way. So XMR is only using 14mb. Also the affinity is a big player to get the most. Shocking for me was XMR got more when running on the HT and not the core when duel mining.
I have now got it working nice.
Set your Roi miner to main cores and xmr stak change that to the HT of each core. And only use 7 threads for xmr not 8.
My ROI earnings are only just lower than what they was befor adding xmr on to the cpu. But I have seen that the miners hash rate reports less even though roi.supernova round earnings are not much less. And now the added bonus of XMR for the win. Also tests on the mining with GPU and cpu are all good. GPU is as it was.
Again cores 0,2,4,6,8,10,12,14 on ROI and HT on XMR.
Hear is my XMR Stack CPU conf.
"cpu_threads_conf" :
[
{ "low_power_mode" : false, "no_prefetch" : true, "affine_to_cpu" : 3 },
{ "low_power_mode" : false, "no_prefetch" : true, "affine_to_cpu" : 5 },
{ "low_power_mode" : false, "no_prefetch" : true, "affine_to_cpu" : 7 },
{ "low_power_mode" : false, "no_prefetch" : true, "affine_to_cpu" : 9 },
{ "low_power_mode" : false, "no_prefetch" : true, "affine_to_cpu" : 11 },
{ "low_power_mode" : false, "no_prefetch" : true, "affine_to_cpu" : 13 },
{ "low_power_mode" : false, "no_prefetch" : true, "affine_to_cpu" : 15 },
],
as you can see I have left the 1st thread off. This lets the CPU breath abit. If you use all of the threads she bottles. I found XMR and roi to be slower mining on the cores with xmr. Again maybe this is down to the 1800X cpu. It may well not be the same on others so playing is the key.
Also playing with the cores/threads have been done. I found this to be the best setup giving me over 440hs on XMR. So cant complain.
Again I would like to point out that this DUEL mining would be best for someone who mines XMR and is looking to fill there cpu to get the most from there rig. Roi miners can also get a nice bit of XMR if they have a big cpu such as a xeon or ryzen to max the profits.
If you are on a laptop mining Roi its not going to go so well on xmr. EG... My Laptop is a 3mb i5 2 core 4 thread. Mines ROI nice getting me around 80 to 100 coins a day. But XMR it would be lucky to hit 10hs.
Later in the week I will upload a vid to the ROI youtube and you can see my rig doing its thing.