the option of "--cuda-sheduler 2" is not an option too thought for nvidia in windows, yesterday I was testing it in different rigs, both 4, 6 and 8 cards.
as I in manual I have everything very optimized, that option only gave me 1 more mhs, but leaves the computer fried. DA equals 4 that 8 cards, and imcluso with a card, it goes to 100% all the time the cpu, and does not deserve to have a RIG that is at 34% of cpu giving me 121mhs, that is always 100% cpu and get 122 mhs.
Reading a lot of information on that option, it is quite used in Linux rigs, but it is not used in Windows.
Also once you activate the rig becomes unstable, does not turn off or freezes, but becomes unstable even if you turn off the miner, you have to restart to leave the rig again well.
You who search according to say the greater stability has added an option that is the opposite of what you are looking for. If you want more performance, do not make the computer suffer by having one thread per card, because when I want to show it is not optimal or better.
Sorry, but you are mistaken. Cuda-Scheduler works on both Windows and Linux. Klaust added it to the Windows version of his miner in 8.21 and it was in Tpruvot before that. On a rig where the CPU has more processor cores than there are video cards, it can boost GPU performance because it reduces the amount of time that the miner process has to wait for a thread on either operating system. You can read more about Cuda Scheduler here:
https://stackoverflow.com/questions/11953722/how-to-reduce-cuda-synchronize-latency-delay.
As you mentioned, it can overburden the CPU if a rig has more GPUs than CPU cores or the CPU itself is under-powered. That is why the option is off by default. Users can choose to enable it when it makes sense on their system and they do not have to enable it for every card (which is another benefit of using a separate mining process for each GPU - you can tune the miner for each GPU instead of applying the same settings to all cards).
Most of the miners use a minimum of 6 graphics cards and a celeron, pentium g4400 and some like me up to i3, and it always takes 100% of the CPU, I get more HASH if I have it unmarked. You should warn by selecting it the same thing you do when activating the OC, a good warning. Because many can give you a bad experience and have a wrong idea about your program.
You can also see how many cores the processor has and how many cards there are in the rig, and to allow it to be selected or not, that would be optimal.
I in 4 different rigs, in the 4 I had problems. In other words, the vast majority do not need them, warn them well of the problems they can give or only allow them to select it if they have more cores than cards.
I do not even a serious miner spend $ 300 on a micro, when with a micro $ 80 intel g4400 you have left to mine.
THE option has its function, and will serve especially those that only have 1 card and a lot of CPU, for example a gamer that wants to enter the cryptos. But the more appropriate it is for everyone, including the group that most interests you, the medium and large miners, the more useful it will be and the more it will gain.
I'm not saying that the option is bad, only that it should better warn or control the number of nuclei to allow it to be used or not, so it will be much easier for newcomers or new people in the Soft.
I've introduced another CPU-related optimization in 1.8.4 that is automatically disabled based on the number of CPU cores. However, the CUDA Scheduler is device-specific, so even a user with a low-powered CPU could still enable it for certain cards and not others. For example, someone with a 1080 and a 1060 powered by a i3 CPU could enable the CPU Cuda Scheduler for just the 1080 and not have a considerable CPU usage penalty. I also disagree about your assertions about the impact that this feature has on CPU usage. On my development machine, which is an i7, I often code, mine on a 1070ti and a 1080 with the CPU Cuda Scheduler feature turned on and run BOINC on several CPU cores and do not exceed 70% CPU utilization. I also use the CPU Cuda Scheduler on my rigs that have more GPUs and Ryzen 5 CPUs and their CPU usage is still low enough to also run Folding@Home on those systems. The only reason reason why this feature fully utilized your CPU is because you decided to enable it for all of your GPUs at one time on a CPU that doesn't have many cores.
I understand that some people who spend considerable money on GPUs want to save a little money on the CPU. However, whether or not they are mining with all GPUs as a single process or as individual processes, any miner (such as CCMiner) that validates results on the CPU before sending it to the pool will have to block the mining thread while that work is being done. The slower the CPU, the longer the time it takes for that work to be done, holding back the other GPUs from submitting their work. CPUs with more cores can also process results for more GPUs simultaneously. For really under-powered CPUs that only have a couple of processing cores, it is best to use an operating system like Linux that has lower latency and less greedy background processes than Windows 10.
That is why, despite your numerous pleas, I am not going to be rewriting my software to group devices into a single miner process. I made an informed design decision to assign each GPU to its own miner process because it offers lower CPU latency, better customization of the individual devices and miners, the ability to select different algorithms on rigs with different types of GPUs and has a higher fault-tolerance since a failure with one device/miner won't affect other devices. As with every design decision, it is compromise between multiple factors and there may be some cases where it is not the optimal implementation for a given algorithm on a specific hardware configuration. However, no single piece of software can ever be the ideal solution in every situation. There are no upfront costs to trying my software and it offers a variety of configuration options so that users can tune it to fit their hardware. Most reasonable users can make a rational decision as to which mining software works best in their situation.