You may be able to use the ram you have but it's very unlikely it will run at XMP speed of 2800mhz with the Xeons you have listed. I used an E7 8890 v4 (ES) and was limited to around 2400mhz. I could however tighten the timings a bit. I used 2 x 8Gb Corsair Vengeance 2400C12. Using a E5-1680v3 Xeon and I can clock memory to much higher speeds.