I apologize in advance for the long post.

Short version for the lazy:

At stock clocks, the RX 470 and RX 480 both get hash rates close to 1450 kh/s when mining Boolberry. (If they have slighly OC'd 2000 mhz memory.) You might be able to squeeze out another 300 kh/s with a modded BIOS, however.

Long version:

The RX 480, even with a modded BIOS, does not seem to perform better than an RX 470. According to http://1stminingrig.com/how-to-mine-boolberry-bbr-with-amd-nvidia-gpu/, an RX 470 can do 1450 kh/s easily. Even with the significantly higher core clock speed (1338mhz), my factory OC'd XFX RX 480 pulls almost exactly 1450kh/s at stock speeds. They both pull 1450kh/s at their stock speeds and they both have slightly higher memory clocks of 2000mhz. Only overclocking the memory seems to have any real effect. That probably isn't just a coincidence. It looks like memory is a more serious bottleneck for Boolberry mining than it is for other coins.

The only way to get any more performance is to use a modified BIOS like mine. My modded BIOS with faster memory timings and a 2150mhz memory clock speed gives me another 300 kh/s or so on my RX 480. I wouldn't be surprised if an RX 470 could get very similar performance to my card if you used the same memory timings and clocks. Just don't blame me if you try this and your RX 470 turns into a paperweight!  

Here's my modded bios: https://www.dropbox.com/s/l8mvq99rc17g7ne/xfx-rx-480-8gb-boolberry.rom?dl=0 Just keep in mind that it's made for the specific model of the card I'm using (RX-480P8DBA6). Flashing it on another one could be... bad. I'm sure you could use the Polaris BIOS editor to copy the memory timings, clocks, and voltages from this BIOS over to one from another model of the RX 480 if you wanted. It's more or less standard procedure for a modified RX 480 BIOS.

Here are some screenshots of the miner running on my RX 480:

Stock bios: 1450 kh/s


Modded bios: 1750 kh/s

I just realized I had this miner confused with another! Just ignore the issue I mentioned a couple posts ago. Sorry about that!

Hey, would anyone here happen to know why the silent  army version of this miner always crashes on my RX 480? The normal version works just fine, but a little slower. I'm using the default settings if that helps. I appreciate any help I can get.

Would anyone here happen to know how well the GTX 1080 performs with Claymore's miner on Windows 10 with the right driver version? I personally do not own one, but I know someone who does. Just trying to figure out if he can get decent Ethereum performance out of it.