Do they really exist , is there a private miners that we don't know about it pulling 2 to 3x what is public miners doing on the same gpus.
I can see on the pools some miners with crazy speeds i can't imagine that they are using such amount of hardware to get this speed , it seems also that the cards are not really loaded when i run any of the public miners like claymore or sgminer .....just asking if there is really something like that..
Public miners made by non-professionals for non-professionals.
Most of them yes. But look at claymore for example. His miners are way on top of other ones and he proved that it can be quite profitable even for him (when he publicly release them and not sell it to a few people)
If i was one of them i wont make it public or sell it, i will just get my hardware and enjoy my 1 month roi .
Well I don't think it's that good. You need pretty high speeds in order to make one month ROI with any GPU. Private miners mostly have 10-20% improvement over public ones. You may say well 10% is not much but it is for people with large farms
This public miners are not really using the hardware at it's max , those gpus can do alot work and you can see it if you have gpu loading monitor even with the fastest claymore my gpu usage can reach 0% and 10% loading for a while like seconds or so and never reachs 100% , 10-20% i can get it easly with some OC or just switching to linux , those hardcore miner are getting at least 2-3x what is a public miner will and thats why i am sure they use there own hardware.
Other guys here explained you why core utilization is low. In fact for ETH what you want to do is lower the core clock and boost memory clock. Claymore is great developer and he is doing best he can. There are always myths that there are this "private miners" (I mean there are but they are not what everyone thinks) that will boost your hashing speed 10 times. Every now and then there is thread on btctalk and instead of opening new one you could've just searched for answer. Of course maybe we are all wrong here and you know that there is miner that will boost your speed 2-3 times ? (yeah right...)
Ok, assume i am wrong go a head, heatup your gpus ,OC them, exhuast them on public miners do big farms and you won't even touch those miners i am talking about ,becuase they are pro.programers can make thier own miners for thier own hardware.