Asrock b250M Pro4 + Single rank Ram

Solution
Your odds of success are less than 100%.

My suggestion is to buy a 2 x 8gb supported kit.
Then see if your existing 8gb stick works in addition.
If it does, you have 24gb; if it does not, sell the 8gb or keep it as a spare.
Your odds of success are less than 100%.

My suggestion is to buy a 2 x 8gb supported kit.
Then see if your existing 8gb stick works in addition.
If it does, you have 24gb; if it does not, sell the 8gb or keep it as a spare.
 
Solution

Gio_3_

Prominent
Mar 2, 2017
11
0
510
• Dual Channel DDR4 Memory Technology
• 4 x DDR4 DIMM Slots
• Supports DDR4 2400/2133 non-ECC, un-buffered memory*
* 7th Gen Intel® CPU supports DDR4 up to 2400; 6th Gen Intel®
CPU supports DDR4 up to 2133.
• Supports ECC UDIMM memory modules (operate in nonECC
mode)
• Max. capacity of system memory: 64GB
• Supports Intel® Extreme Memory Profile (XMP) 2.0
• 15μ Gold Contact in DIMM Slots

whats about this? this is written in my mobo manual
 

Gio_3_

Prominent
Mar 2, 2017
11
0
510


• Dual Channel DDR4 Memory Technology
• 4 x DDR4 DIMM Slots
• Supports DDR4 2400/2133 non-ECC, un-buffered memory*
* 7th Gen Intel® CPU supports DDR4 up to 2400; 6th Gen Intel®
CPU supports DDR4 up to 2133.
• Supports ECC UDIMM memory modules (operate in nonECC
mode)
• Max. capacity of system memory: 64GB
• Supports Intel® Extreme Memory Profile (XMP) 2.0
• 15μ Gold Contact in DIMM Slots
 
By supported kit, I mean to go to a ram web site, preferably the same as the ram you currently have.
In their ram selection app enter your motherboard and you will get a list of supported kits.
Pick one and install it.
If your old ram works along with it so much the better.