RAM Compatability with Core i7 8700 Coffee Lake

[daonlynamenottaken]

I am still in the process of selecting parts for the computer I am building, I won't play any games on it but am going to day trade every day. Anyways, I read that most games are able to be played well with only 16 GB of RAM, so I decided to cut down from 32 to 16.

The question: Under the "specifications" tab for the coffee lake it says "memory: DDR4 2666", does this mean that any ram over 2666 won't be used to its full extent? Also I will have 2 extra memory slots, if I want to insert 2 more RAM cards later that are a different number/speed, will it harm the motherboard or something? Thank you!

 

[geofelt]

Your first consideration is how much ram you need.
You want sufficient to keep all of your active apps in ram to avoid accessing the page file.
I can't say if 16gb is enough.
But, if you are thinking about adding more ram later; don't.

Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards can be very sensitive to this.
This is more difficult when more sticks are involved.
That is why ram vendors will NOT support ram that is not bought in one kit.
It is safer to get what you need in one kit.
But, it is a bit more expensive because of the added matching of all the sticks to insure compatibility.

Since 8700K is dual channel only, you can do better with a 2 x 16gb ram kit.

The spec 2666 says at what speed the cpu/motherboard will boot at, not the maximum speed.
All ram starts at 2133/2400/2666 so you can boot into bios and set a higher speed.
This is done via accessing the XMP profile.
XMP specs are imbedded in faster ram and are used to set a higher speed(technically overclocking by setting a higher than stock 1.2v)

The higher the ram speed, the higher the latency(CAS) which tends to take away some of the effectiveness of higher speed.
Intel ram controller is very good, so high speed ram is not essential.
I might suggest 3200-3600 speed would be appropriate.

You want documented ram compatibility. If you should ever have a problem, you want supported ram.
Otherwise, you risk a finger pointing battle between the ram and motherboard support sites, claiming "not my problem".
One place to check is your motherboards web site.
Look for the ram QVL list. It lists all of the ram kits that have been tested with that particular motherboard.
Sometimes the QVL list is not updated after the motherboard is released.
For more current info, go to a ram vendor's web site and access their ram selection configurator.
Enter your motherboard, and you will get a list of compatible ram kits.
While today's motherboards are more tolerant of different ram, it makes sense to buy ram that is known to work and is supported.

Lastly, there is no need for fancy heat spreaders. They are all about marketing and can be a negative if they conflict with the cpu cooler. Low profile is best.

You might list the rest of your specs for a check.