I tried this configuration but after 2 hours, the rig crash and reboot.
Yet I obtained 33 MHz for 50 W !
Too bad 
After a few hours of mining with these new OC settings, my GPU 5 crashed and displayed the error message “GPU driver error, no time” so I set all my gpu with the VDD to 630 except GPU 5 and since all works well. My 6-card rig has been very stable for 24 hours with these OCs. If you know how to fix the problem I had with GPU 5 that would be great. Thank you.
If it dies you cant lower it more than this. But you can put 636 or 640 as voltage.
When I put 640, or 636 or 630 VDD on my GPU 5 it crash.
go 1135 on memory and see what that gives you.
try 700 for vdd, lower by 5 every few hours until crashes, then go back up.
Powercolor RX 6600 XT 8 GB Red Devil | 0.6-210@210918 | TeamRedMiner v0.8.5
Running for 12hrs+ with no rejected shares.
Very power efficient config if your card is stable at these settings.
(thanks to rkulov for the VDD 636 setting suggestion)
Lower the Memory clock in increments if it hangs.
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Thank you for sharing. I just changed the VDD to 640, on my 2 rigs (19 X Rx6600 XT sapphire). And I consume 104 less (without loss of performance), (vdd at 600 previously).
these cards can be further tweaked if you know the correct values to set the memory voltage and memory controller voltage.
I imagine. But I don’t know how to do it. The base, maximum, etc. 
probably you did, but lets give it a try…did you enabled csm support in your bios ? helped me on my asus b250 mining expert
my 2 x red devil’s are maxed out on 32 mh/s on Team red miner, tried a lot of different settings, sometimes they jump to 33mh
Hi There,
have a new Sapphire 6600XT that causes havoc on HiveOS 0.6-210@210920. Running a H110 Pro BTC+ ASRock mobo, driver version 20.40 (5.11.0701).
The mobo recognizes the card fine, but upon hiveos boot I get the following error:
amdgpu failed to init sos firmware
Then it all turns to crap. Tried riser swaps, slot swap, putting the card in a full pcie slot. Nothing helps. Below is a screenshot of error.
Tried reverting all the way back to 0.6-207 and no difference in result.
Nice, thx - works on 2 of my 3 cards. 3rd drops zu 28 mh and i think it would go lower if i let 
(I answer to myself). Correction, with 640/630 (core voltage), on all the cards of a rig. The Rig ended up crashing (the miner or hiveos), so I had to put 600 back in value (for all cards).
I had CSM disabled. Now I enabled it and can’t even get two 6600 XTs to work when I’ve had as many as 6 working previous on CSM disabled. These cards are a nightmare.
you will never run several cards on csm enabled … never …doesnt matter which cards
HI, I cant get my 6600XT to run stable. Keep getting GPU detected DEAD.
ANy idea how to solve it?
Thank you
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thanks for the OC recommendations on this thread. put together a rig of different flavors. 2 qick, 1 merc, 2 gigabyte, and 1 powercolor hellhound. having trouble with adding the hellhound. any OC recommendations for it?
I found after running my mixed rig using TeamRedMiner for around 2 weeks with no issues my Hellhound Gpu kept getting detected Dead and rig crashing. Ended up reflashing USB and changed settings
The wattage is now a lot higher but rig hasn’t crashed for last 3 days, but have now also received my 1st ever stale share from a different GPU.
Im going to just leave until the weekend when ill have some free time to play around with oc settings.
I have a mixed rig, too … didnt find any oc for hellhound yet. Most Cards are good in oc. Only Hellhound and Sapphire Pulse X - no idea …
I go one hellhound on 44 Watts with 30,5mh … thats what i can reach - with red devil i reach 32,5 on 44 watts This lottery breaks my heart
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