samsung ssd 850 evo 500gb help migration slow ?

[Abdul_6]

i have i7 6700k
16gb ram
1tb sata hdd
motherboard z170m plus
it has 6gbs port

https://www.asus.com/uk/Motherboards/Z170M-PLUS/

please help why is it taking time to clone my sata drive , my sata drive used 300gb out of 1tb
so please tell me what am i doing wrong , have i connected anything wrong

 

[Abdul_6]

its done 13% now i think its going fast now , just about an hour ago i had 300gb per second transfer speed it cloned 300xgb under 20 seconds , and now i restarted pc and tried to clone again to se the speed of clone its gone slow.

the samsung migration tool shows 20hrs , befoe it cloned under 20 seconds.

am now using Reflect macrium its doing it slow but it will finish within 30min or 1 hour 300xx gb better then waiting 20hrs