What happens if you don't install RAM sticks in pairs?

Question

Iron

When buying a memory stick for a laptop, they began to convince me that for stable operation (and indeed it is necessary) to install and buy sticks in pairs. That is, if there are 2 slots, then you must have 1x1, 2x2, 4x4, 8x8, but 4x8 is impossible, for example.
Now they are 4x8, while the flight is normal. Is this a relic of the old days or is there really something? Help to understand, please.

Answer 1

briefly so
complete - look at all the pictures
people.overclockers.ru/_NooB_/15035/Testirovanie_o...
www.ixbt.com/cpu/intel-ci7-3770k-mem.shtml
PS still yes, if not in slot 0, but there is in slot 1 - it may not start, but this, of course, is an easily fixable case

Answer 2

Many here wrote about two channels, that's right, the speed should be greater.
Why write that there is no special gain? Because there a number of factors must be in order to realize the potential.
The memory works in conjunction with the processor, through the motherboard's bus, because:
1. The processor has a max bus frequency, in the specifications they write which memory is optimal for this processor. Even if you set the memory to 1800, and the percentage works max at 1666, then only 1666 out of 1800 will actually work. The same is true for growth due to two or more channels.
2. The same for the tire of the motherboard, the tire is the road between the process and the memory, if the road is narrow and in traffic jams, then no sports car will help you move along it faster.
3. The channels of the memory \ processor \ motherboard must be multiple, since the processor cannot process information with halves, thirds and other fractional numbers.
and a bunch of other factors that are just too lazy to describe, but in general it’s never superfluous to put in two channels, maybe a couple of factors will coincide anyway.

Answer 3

There is some truth, but it's not all necessary. In this case, the sellers tried to breed for the purchase of an extra module.