xIntensity works by being a shader multiplier for the thread intensity. It gives you finer control over thread intensity than just using regular Intensity settings of I1-20 which use a standard 2^x = thread intensity (where x is the intensity setting). You need to specify the number of shaders your card has in your config file to get this, or raw intensity to work properly because, again, xIntensity is a shader multiplier. I’ve used both xIntensity and rawintensity settings before, and let me just say that they are great features, but don’t expect a miraculous 100% increase in hash rate. Using these settings may or may not give you better hash rate, and to be honest, you will be spending a lot more time tweaking your config if you use xIntensity or rawintensity. rawintensity isn’t a multiplier. It’s a method of directly controlling the thread intensity. So going off of the traditional intensity 2^x = thread intensity (where x is intensity setting), you are simply entering the total number of thread intensity rather than using an equation or a shader multiplier. xIntensity and rawintensity settings also require extensive tweaking of the thread-concurrency as well, so traditional values of TC that worked while using standard intensity I1-20 will most likely require different TC settings for every single adjustment you make to xIntensity or rawintensity. So, HW errors are being caused because majsta hasn’t posted the number of shaders, nor have they posted the TC setting, which again is very important for using xIntensity and rawintensity. Here’s a good place to start for learning about xIntensity in particular:
https://github.com/sgminer-dev/sgminer/commit/7aeae40af22e6108aab8b68a229eea25a639d650
xIntensity Example: r9 280x has 2048 shaders
I15 = 2^15 = 32768 thread intensity
I16 = 2^16 = 65536 thread intensity
xIntensity setting 16 = 16 * 2048 = 32768 thread intensity
xIntensity setting 17 = 17 * 2048 = 34816 thread intensity
So using regular I1-20, there’s a huge, exponential jump in the number of thread intensity even at increment +1 (from I15-I16 it’s about a 2x increase in thread intensity). Using xIntensity, there’s a very small increase in thread intensity from xintensity16 to xintensity17, which again, may or may not give you better, or worse, hash rates.
