It seems you didn't read the previous posts very carefully. π
@GuitarGwrote (about modules DDR3 2133 MHz):
"They are more rare than 100$ laying on ground, though. You can use cheaper 1866 mhz, those are easier to find. They work out of box."
Yes, the respected TC has modules 2133 MHz, but it is much more realistic to find modules 1866 MHz (there are even new ones!). So, first, look for HyperX HX321LS11IB2/8, and then, if you donβt find anything, look for HyperX HX318LS11IB/8 (you need two or four identical modules for 16 or 32 Gb of RAM).