Hi,

I used my H110 for a very long time with 13 mixed GPUS. Eventually, I bought a second H110 and 13 rx 5700 xt graphics cards. I thought everything will be the same straight forward, but I faced a very strange issue. My rig does not boot (post) if I add more than 8 the same model GPUS, i.e. once add 9 rx 5700 xt, click power button there is just nothing comes up.

For example,
8x rx 5700 xt = boots fine
8x rx 5700 xt + 3 rx 570 8gb = boots fine
9x rx 5700 xt = fails to boot

I did try all the suggestions in a similar topic
http://forum.asrock.com/forum_posts.asp?TID=6589&PN=2&title=h110-pro-btc-cannot-boot-with-more-than-9-gpu

added more rams
configured GPU as Parsec in the topic above suggested
my CPU supports 32 PCIe lanes
I did try changing all cables, risers
I have 3x850W power supplies which provides more than enough power for 9 gpu

Setup:
H110 pro BTC+
Intel G3930 CPU
4GB Ram
500GB Sata SSD
13x RX 5700 XT
3 x Corsair RM850X PSUs (850 Watts each).

Any ideas why the rig works perfectly fine and stable using 13 mixed cards or 8 same and 5 other brand cards, but it does not work once I add 9 same model cards?

I've tried that already, sorry didn't mention this earlier. So basically every time I try to increase memory clock and/or decrease clock speed, my hash rate slightly drops. Not sure whether its due to changes I've made or there is actually something changes. I've tried 1200/2000, 1250/2150 etc, but in any case hash rate just drops.

Afterburner works perfectly fine on my gtx 1070 and increase hash rate significantly but does not have any positive effect on my rx570

Thanks for your reply. As I've mentioned previously, I've already modified my bios replacing 1750 to 2000 using polaris app and ran atikmdag-patcher. That's how I've increased my hashrate from 18 to 24 Mhs

Hi, I have the same problem. My out of the box rx 570 sapphire nitro + 8gb has only 18.** Mh/s hash rate only.

My GPU has Hynix memory with Bus width 256 Bit.

GPU  I've modified bios copying strip 1750 to 2000, using the latest blockchain drivers 17.30.1029, Afterburner 4.4.0 beta 16 and manage to increase my hash rate to 24.** Mh/s. Any ideas how can I push hashrate to at least 29 Mh/s?