Power Supply
 
If anyone could help answer my questions, it would be greatly appreciated,

1) How do you calculate the number of watts needed for your GPUs?  In my case, I want to power two GPUs that require a total of 400 watts. So then do I buy a 500w power supply to cover my needs running at 80% efficiency.

2) If I build my rig with modularity in mind, would it be safe to assume that I need to purchase another 500w power supply to support another two 3060ti GPUs. So on and so forth with every two GPUs '

3) Should I only trust 80 Plus certified power supplies or can I cheap out for a Chinese model?

Hello Friends,

Be advised this is a longer post, I am very curious and as you can see for yourself in a few moments, very serious about mining. I want to learn more, I want to follow through with this. So if you don't have anything productive to say, please do not waste your time with this post.
Now, I’m new to this so if there is anything at all that my ignorance is not allowing me to see, please shine some light on it.

For the past 3 months, I have been trying to research and investigate crypto mining and I feel comfortable enough to attempt to build my very own rig.
After many long hours, I finally want to begin thinking about purchasing a few key components. However, I ran into a few problems and I am hoping I can find some solution here.

Key Aspects of my build
1) I want to build a rig that is modular so that I can expand when I am financially available
2) I want to begin with two 3060ti GPUs

Problem 1
Power Supply
 
- How do you calculate the number of watts needed for your GPUs?  In my case, I want to power two GPUs that require a total of 400 watts. So then do I buy a 500w power supply to cover my needs running at 80% efficiency.
- When do want to add more GPUs? Would it be correct to assume that I need to purchase another 500w power supply to support another two 2060ti GPUs
And if I have understood this correctly, should I just buy a 1000w power supply in the first place?
- Question; Should I only trust 80 Plus certified power supplies or can I cheap out for a Chinese model.


Problem 2
Motherboards 

- I did have a hard time understanding motherboards. So instead of asking, I am just going to tell you what I know.
- There are five types of PCI slots x1, x4, x6, x8, and x16
- There are different transfer data rates. 2.0, 3.0, 4.0. The higher the better. My question with this topic is, does it actually matter purchasing a 3.0 vs a 4.0. I understand that there is a speed difference, but more so I am asking if there is a noticeable difference.
- Risers and splitters give you the option to have your GPUs connected elsewhere on your rig
- Those are the main parts that I understood, now some questions that I have
- Question; how do you find or calculate the maximum amount of GPUs that a given motherboard is capable of running efficiently?
- Question; is it best to buy a motherboard that has a set number of PCI-e slots and only use what is available? Or can I buy a motherboard that has, say 4 PCI-e slots, and use four splitters giving a total of 16 PCI-e slots that are available to use efficiently.

Problem 3
Hardware

Now that I am here I might as well triple check the hardware that I need in order to have a fully operating Mining Rig using NiceHash
- Some sort of frame
- Motherboard
- CPU that fits the motherboard
- CPU cooling fan? (optional? Or is it highly recommended)
- Nvidia GPU(s)
- Powersupply
- Risers
- Splitters (if this route is available)
- M.2 (i have no idea what this is or how many I need) (is this an SSD)
- RAM (also do know how much I need, will 2x 8GB, 16GB total be enough? They perform better if they are from the same manufacturer or can use different manufacturers)
- Storage (I’ve read I don't need a lot, so I'm guessing 500GB. Is it worthwhile to purchase a 1TB) 

For those who stuck around until the very end, thank you, I truly appreciate it. For those willing to hand out guidance, I will be eternally grateful and in your debt.
 

Hello friends,

Another question, I've heard time and time again that CPU, RAM, and SSD/HDD does not affect mining.

I want to know the specifics as to why it does or does not. If anyone is able to break it down for me or lead me towards the right direction I would greatly appreciate it. 

Hello friends,

Does anyone know what percentage does NiceHash take from you when you mine?
Is there a coin minimum that you have to have before withdrawing?
And are there alternative places like NiceHash that are better to use to mine altcoins?

Hello friends,

I am seeking guidance from those who are well versed in GPU mining. Perhaps there is an individual(s) on this forum who are willing to spend a few minutes of their day to convince me that mining, after all, is a bad idea. Each time that I crunch the numbers factoring in initial investment, ROI, the unpredictability of the crypto market, and the amount of electricity used, I end up coming up negative. 

In addition, I do not have any knowledge of what to actually do once I have the physical mining rig set up right in front of me. Such as
- Mining software?
- Configuration of mining code?
- Optimal settings for GPUs by using drivers? 
- Which pools should I join?
- How to join a pool?
- What is my ignorance not allowing to me realize that is so obvious for someone that knows exactly what they are doing?
And other equivalent topics.

Nevertheless, mining is something that I truly want to follow through on, I believe there is a lot to learn and a lot to gain from mining when it is done right.

And that friends is my dilemma, how is it done, right. 
(any information provided will be taken into consideration and greatly appreciated. Cheers)