diff --git a/csrc/CMakeLists.txt b/csrc/CMakeLists.txt
index 005607a..3f51c27 100644
--- a/csrc/CMakeLists.txt
+++ b/csrc/CMakeLists.txt
@@ -6,6 +6,7 @@ set(CMAKE_VERBOSE_MAKEFILE ON)
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3 -fPIC")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O3 -fPIC")
 set(CUDA_SEPARABLE_COMPILATION ON)
+list(APPEND CUDA_NVCC_FLAGS "-DENABLE_FAST_DEBUG")
 list(APPEND CUDA_NVCC_FLAGS "-O3")
 list(APPEND CUDA_NVCC_FLAGS "--ptxas-options=--verbose,--register-usage-level=10,--warn-on-local-memory-usage")
 
diff --git a/csrc/kernels/configs.cuh b/csrc/kernels/configs.cuh
index 8893b79..12a0c26 100644
--- a/csrc/kernels/configs.cuh
+++ b/csrc/kernels/configs.cuh
@@ -7,9 +7,14 @@
 #define NUM_BUFFER_ALIGNMENT_BYTES 128
 
 #define FINISHED_SUM_TAG 1024
+#define NUM_WAIT_NANOSECONDS 500
+#ifndef ENABLE_FAST_DEBUG
 #define NUM_CPU_TIMEOUT_SECS 100
 #define NUM_TIMEOUT_CYCLES 200000000000ull // 200G cycles ~= 100s
-#define NUM_WAIT_NANOSECONDS 500
+#else
+#define NUM_CPU_TIMEOUT_SECS 10
+#define NUM_TIMEOUT_CYCLES 20000000000ull // 20G cycles ~= 10s
+#endif
 
 #define LOW_LATENCY_SEND_PHASE 1
 #define LOW_LATENCY_RECV_PHASE 2
diff --git a/csrc/kernels/launch.cuh b/csrc/kernels/launch.cuh
index 92f3295..7fd2815 100644
--- a/csrc/kernels/launch.cuh
+++ b/csrc/kernels/launch.cuh
@@ -58,12 +58,9 @@ cfg.dynamicSmemBytes = smem_size;
 #define SWITCH_RDMA_RANKS(case_macro) \
     switch (num_ranks / NUM_MAX_NVL_PEERS) { \
         case 2: case_macro(2); \
-        case 3: case_macro(3); \
         case 4: case_macro(4); \
         case 8: case_macro(8); \
         case 16: case_macro(16); \
-        case 18: case_macro(18); \
-        case 20: case_macro(20); \
         default: EP_HOST_ASSERT(false and "Unsupported RDMA ranks"); \
     } while (false)