Question 8GB DDR4 HyperX 2666 doesn't work but a 4GB DDR4 HyperX 2666 works?

[chef_francishd]

8GB DDR4 HyperX 2666 doesn't work but a 4GB DDR4 HyperX 2666 works?

Build specs:

Intel Core i3-8100
MSI H310M PRO-VDH PLUS
8GB DDR4 HyperX @ 2666 (Supposedly), Single Stick
GPU is TBD
1TB Seagate Barracuda

Recently while I was working on a new build after so long. I ran into a problem I've never encountered ever. When I tried to boot up the system, the debug light on the motherboard lights up telling me that there's a problem with the RAM and so I was stumped because it says on the mobo specs that it could support up to 2666. I didn't know what else to do. Until I bought and tried a DDR4 4GB HyperX Memory still @ 2666 and it worked. Computer booted up and I managed to set up Windows 10. If anyone can help me with this problem, I would be very thankful because I need at least 8GB of Memory.

 

[Calvin7]

2666 MHz for I7 and I5 processors only.

Memory modules sold as Single modules have no guarantee to be compatible if used in multiples.

I suggest using a kit of two 2400MHz modules.
https://www.amazon.com/dp/B016A29ETY/ref=psdc_172500_t1_B075RLKL4L

 

[chef_francishd]

I mean the Single-stick 4GB 2666 works but should I just stick up to 2400 for a Core i3 build then? Also, because I'm from a 3rd-world country which makes it more expensive to buy these parts, what do you think of a single stick 8GB HyperX @ 2400? Can it work? I can't really experiment with it since experimenting comes with a big price. Because I plan to buy it another 8GB HyperX sometime soon. Thank you.