I also try this syntax
-k x16r -o stratum+tcp://rvn.suprnova.cc:6667 -u user.worker -p workerpass --gpu-platform 0
I found description for --gpu-platform 0:
gpu-platform 1 This is an option field to indicate to sgminer which video platform to use. Using 1 as in the example is only needed if you have a built-in video such as with some Intel based motherboards.
As with all things computers, the platforms start with 0, meaning 0 is for the built-in graphics, so we want to use 1 or the AMD graphics cards. If you get an error on startup about finding no platform, it means sgminer cannot find a compatible graphics platform on which to run, this means your probably do not have built-in video or is is not activated. In either case you can change the one to zero, or even eliminate this entry completely. In my example I do not need this option, so I just removed it.
Their example
sgminer.exe -k x16r -o stratum+tcp://miningpanda.site:3636 -u RGvCLDzUAYPoryFBxd8zwUjJCi4bckQZgg -p c=RVN -I 19 --gpu-platform 1 -L log.txt
Ater that I get this error...
GPU2:
Memory state 2 clock: 2000 -gt; 2222.
DPM state 3 core clock: 1145 -gt; 1155.
Voltage table index 3: 65284 -gt; 925.
GPU3:
Memory state 2 clock: 2000 -gt; 2222.
DPM state 3 core clock: 1145 -gt; 1155.
Voltage table index 3: 65284 -gt; 925.
GPU4:
Memory state 2 clock: 2000 -gt; 2210.
DPM state 3 core clock: 1145 -gt; 1153.
Voltage table index 3: 65284 -gt; 925.
============ Starting Miner ===============
[19:46:07] Started sgminer
[19:46:07] * using Jansson 2.7
============ Starting Miner ===============
[19:46:07] Started sgminer
[19:46:07] * using Jansson 2.7
[19:46:07] Started sgminer
[19:46:07] * using Jansson 2.7
[19:46:07] Probing for an alive pool
[19:46:07] rvn.suprnova.cc difficulty changed to 8
[19:46:09] Startup GPU initialization... Using settings from pool rvn.suprnova.cc.
[19:46:09] Startup Pool No = 0
[19:46:10] Building binary x16rEllesmeregw256l8ku0big4.bin
[19:47:10] GPUs did not become initialized in 60 seconds...
[19:47:10] GPUs did not become initialized in 60 seconds.../root/xminer.sh: line 76: 3103 Illegal instruction $MINER_PATH $MINER_OPTIONS
Miner ended/crashed. Restarting miner in 10 seconds --------------