Optimizing Hashrate
Once you get Avermore stable, there are a few things you can try to increase your hashrate. The best way to tune your system is by trial and error. Start from a stable configuration, and add these settings one by one; if at any point your system becomes unstable (or the setting doesn't help your hashrate), then revert to the previous best config.
Keep on mind that the hashrate of x16r varies a lot based on the particular algo order of the current block. In order to mitigate this effect when tuning your settings, you can add the --benchmark flag to your Avermore arguments. This will tell Avermore to use a fixed hash order (running each algo once) so that hashrates are more consistent. This is very useful for tuning settings to optimize your hashrate. Keep in mind that shares submitted in benchmark mode are invalid, so remove this flag once you're done tuning and are ready to mine.
The very first setting you should try tuning is the xIntensity. You can do so by changing the -X 256 argument in the sgminer line of your .bat or .sh file. Typically, you want to increment the intensity slowly (by multiples of 64) until your hashrate no longer increases. Typically, the optimal intensity will be in the 128-1024 range. You can tell when the xIntensity is too high when the hashrate starts to fluctuate quickly even when in --benchmark mode.
Adding -g 2 to the sgminer line will tell Avermore to use two CPU threads per GPU. This may increase your hashrate since it allows two CPU threads to queue kernels in parallel. You may need to lower the xIntensity to get this setting to work. Note that Avermore does not currently support more than 13 mining threads, so if you have more than 6 GPUs you can individually choose add up to 13 threads manually using e.g. -g 2,2,2,2,2,1,1,1 if you have 8 cards.
Typically, setting worksize to be 64 is best (-w 64). However, you can try setting higher worksizes like -w 128 or -w 256, which might work better for older cards.
x16r and x16s use core a lot more than memory (i.e. opposite of ETH). Thus, if you've previously flashed an ETH BIOS tweak to your AMD card, you will want to revert to stock BIOS settings.
x16r/x16s/xevan uses more core than memory. Thus, you can consider increasing core speed, while leaving memory at stock.
Some people have reported getting better hashrates on the August 23 Blockchain drivers over the regular gaming/video-optimized drivers. Consider testing them out if you haven't already.