Choosing memory

[Mathew Schau]

Alright. So I am planning on buying an i5 6600k with a z-170 motherboard. My question is what specs on the RAM actually matter for compatibility. Obviously there are ddr3 and ddr4, but what about the other numbers like the 2400 and the 3000 after the it. Do I have to buy a certain type in order for it to be compatible, or is it simply rating the speed? I also noticed that the motherboard has 4 DIMM slots on it however intel's index say that the 6600k can only support dual channel set ups. Lastly, when it says it supports dual memory configuration does that mean I can't just put one stick in. Please help, I am thoroughly confused. 

[SLAYR]

Ddr# only fits only in a ddr# socket.

 

The number behind that is the frequency that the ram runs at.

 

Dual channel doesn't mean that you can't use one stick, just that if you use two/four sticks they will run faster, but is not noticible for most tasks.

 

I would suggest some ddr4-2133, or 2400 ram.

[Vitalius]

In most cases, the only thing that matters is the generation. Generation is DDR3 or DDR4.

Memory speed in Megahertz is the number after that, i.e. 2400, 3000, wtv. That matters only if you buy higher speed RAM. Some motherboards don't support higher speeds. In most cases, higher speeds are pointless.

Then there is timings. That's usually displayed as 7-7-7-21 or something similar. These also generally don't matter and only matter when overclocking (essentially). 

Then there is voltages. There is low voltage RAM and regular voltage RAM. Low voltage only works in some motherboards IIRC. Again, it only matters if you intend to overclock or found some nice deal on low voltage RAM.

Lastly, there is RAM capacity. Only some motherboards support higher capacities, but all motherboards support capacities the average user or gamer would need like 8-16GB. Usually capacities higher than that are unnecessary for most people and some motherboards only support 32GB instead of 64GB or 128GB (more than most people need at this time).

There is dual channel vs quad channel. Dual means it is essentially able to access two RAM sticks at once. Thus, doubling their speed (like RAID 0). Quad means it can do the same, but for four sticks, so quadrupling (4x) their speed. Generally, most people won't notice the difference. RAM sticks aren't sold as compatible for different channel types though so it doesn't really matter when considering RAM choices. 

[Mike Soda]

7 minutes ago, Mathew Schau said:

Alright. So I am planning on buying an i5 6600k with a z-170 motherboard. My question is what specs on the RAM actually matter for compatibility. Obviously there are ddr3 and ddr4, but what about the other numbers like the 2400 and the 3000 after the it. Do I have to buy a certain type in order for it to be compatible, or is it simply rating the speed? I also noticed that the motherboard has 4 DIMM slots on it however intel's index say that the 6600k can only support dual channel set ups. Lastly, when it says it supports dual memory configuration does that mean I can't just put one stick in. Please help, I am thoroughly confused. 

Since others here pretty much answered everything else I'll just add one quick tip. Figure out how much RAM you want then pick the DIM(s) with the highest speed but also lowest latency. An 8GB stick of DDR4 2133 at 12 latency would be better than a 2400 at 15, but if some DDR4 2666 has 13 latency then that's probably worth the sacrifice.

[Mathew Schau]

Sounds goods, thanks for the clarification.

[FlushaDev]

Hope this helps