2x gigabyte 1070ti strix gaming keep failing

green-artichoke

Prominent
Jan 7, 2018
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510
hi,this is my first ever thread

so,i have worked this all night long. i had 6x amd gpus (rx470 and rx580) worked perfectly and later i upgraded into gigabyte 1070ti strix gaming. i tried to put one on,it worked perfectly. but when i put on the second one,both gpus were suddenly undetected. i have tried both one by one,each gpu will work fine if it works alone. any thoughts?

things i tried:
-re install windows along with nvidia driver clean installation
-change between pcie slot
-change gpu power cable and sata power
-try each card one by one
-update latest bios version
-enable 4g decoding
-set my virtual memory to 16gb

brief specifiaction of my rig:
-motherboard asus b250h strix
-8gb ram
-processor intel G4400
-power supply corsair hx1000i

any help would be greatly appreciated. thank you