Is this speed ok or I can go higher?
Using 5X480s with 1500 straps
Ubuntu 16.04
amdgpu-pro 16.40
How did you get that speed, can you give me the sample of your bat file, I also using rx 480 8gb stock rom and only got 200-230hs
The fact that you said "bat file" says it all. The post you quoted is running linux, not Windows. Optiminer even says in his README that the best performance for the RX series is obtained on linux, because the Windows AMD driver doesn't provide some of the extensions he needs to get the best optimization, at this point. Claymore is in the same boat, although he isn't fond of linux, so ...
How do you change straps to 1500? On ubuntu 16.04 with amdgpu 16.50 I am getting 290 S/s with RX480-8G on stock cards.
First you need to extract the GPU BIOS and keep a back up file, I use atiwinflash but its a windows application, dunno in linux.
Then with a BIOS editor, you change straps and save save as name.rom, again the ones I use are windows base and not linux.
Once you are done you need to flash the new modified BIOS into the GPU and reboot.
Make sure you save the original bios tho