set `srided_index = true` as default

Change the default for strided index. Th euser feedback shows that strided_index = true will give a view hashes more per second.

doc/tuning.md

@@ -86,4 +86,4 @@ export GPU_SINGLE_ALLOC_PERCENT=99
 ### Scratchpad Indexing
 
 The layout of the hash scratchpad memory can be changed for each GPU with the option `strided_index` in `amd.txt`.
-Try to change the value from the default `false` to `true`.
+Try to change the value from the default `true` to `false`.

xmrstak/backend/amd/autoAdjust.hpp

@@ -123,7 +123,7 @@ private:
 			// set 8 threads per block (this is a good value for the most gpus)
 			conf += std::string("  { \"index\" : ") + std::to_string(ctx.deviceIdx) + ",\n" +
 				"    \"intensity\" : " + std::to_string(intensity) + ", \"worksize\" : " + std::to_string(8) + ",\n" +
-				"    \"affine_to_cpu\" : false, \"strided_index\" : false\n"
+				"    \"affine_to_cpu\" : false, \"strided_index\" : true\n"
 				"  },\n";
 			++i;
 		}

xmrstak/backend/amd/config.tpl

@@ -6,11 +6,11 @@ R"===(
  *   worksize    - Number of local GPU threads (nothing to do with CPU threads)
  * affine_to_cpu - This will affine the thread to a CPU. This can make a GPU miner play along nicer with a CPU miner.
  * strided_index - switch memory pattern used for the scratch pad memory
- *                 false = use a contiguous block of memory per thread
  *                 true  = use 16byte contiguous memory per thread, the next memory block has offset of intensity blocks
+ *                 false = use a contiguous block of memory per thread
  * "gpu_threads_conf" :
  * [
- *	{ "index" : 0, "intensity" : 1000, "worksize" : 8, "affine_to_cpu" : false, "strided_index" : false },
+ *	{ "index" : 0, "intensity" : 1000, "worksize" : 8, "affine_to_cpu" : false, "strided_index" : true },
  * ],
  */