I replaced my laptop from 2 RAM bars with Singel RAM today?

Is it really bad if i have 1x 8 GB instead of 2x 4GB + 2GB in my laptop?

Both are with 1.5 volts per slot. = 3 volts?

then a DDR 3 RAM bar with 8GB 1 slot is occupied. But better than if both slots are occupied? (have no idea)

Dual channel. 3 volts consumption? Single channel 1.5 volts? That can't be worse for the processor, can it? Can anyone tell me the pros and cons?

Dual Channel does not need 3v, they are connected in parallel, not in series.

And actually rather 1.2V at ddr3L

2 modules are really better than one. You can only pack in modules of a certain size.

Of course, you use a little more electricity with 2 bars. But that is rather small and is usually neglected.

Dual-channel almost doubles the read / write speed of the memory. This makes itself felt in memory-intensive programs and games. Effectively only in the range of 5-10% for games, but for video editing etc. It can be a good 20%.

Does that mean I slow down my laptop if I only occupy 1 slot? There are more ram chips being powered, right? If two eaters eat from 1 plate, you only get half full?

Laptop has dual core 1900 MHz. SDD hard disk 500 GB. Now 1x 8 GB RAM. Before that 2 from Samsung. 4GB and 2GB. Have now seen 2 GB more but only 1 slot. Can it be that 2 ram bars mutually unite more than single RAM? Because there's more electricity and more circuit board?

Yes, with 1 latch your laptop will slow down.

Your mistake is that you assume that all food from the plate is needed. In your example, all the chips will be full. The RAM slot can supply far more energy than manufacturers calculate when manufacturing their bars, or a RAM bar usually never uses the maximum capacity of electricity that the slot could deliver.

As kelry says.
Your motherboard and CPU easily have enough power for both RAM bars.

But, the question is 2 * 4gb + 2gb, that's 3 RAM bars and 10gb.

So how is that actually?

First RAM 4GB has 16 chips. Second RAM. 8 chips. Together 24 chips each 256 MB.

the new one has 16 chips of 512 MB each. = 8 GB. When fewer chips are supplied with electricity and processed. Less volt voltage flows. Is that better for the processor?

No, that's not better.

Volt and voltage do not flow. Different amounts of electricity flow. But it doesn't matter, that's what the processor is designed for

Waste heat can also be higher with two bars. Can, need not. 2x single-ranked RAM produces as much heat as 1x dual-ranked RAM. However, there's more space around the RAM bar so that the heat can go away.

The typical heat build-up in the CPU and GPU are in laptops. If something cooks first, it is there before you have to worry about RAM temperatures.