same frequency

Hey everyone, I've had 2x8 CMU16GX4M2C3200C16R, which worked just fine, both XMP and DOCP (switched from Intel to AMD recently). I decided to get another pair of same RAM sticks (2x8). I received them today, installed them and noticed that although they have same number, they don't work good...

I have have a 980ti hytbrid 6gb card. which iv been told is fine for 4k gaming not at ultra but good. so i bought a 4k montior Asus 28inch 1ms 60 hz monitor. I plugged it into the gpu with HDMI and it was super laggy with the mouse and overall not smooth like 1080. Called asus and they said to...