diff --git a/runtime/Makefile b/runtime/Makefile
index ef5ce64..af244da 100644
--- a/runtime/Makefile
+++ b/runtime/Makefile
@@ -10,10 +10,10 @@ PAGE_SIZE := $(shell getconf PAGESIZE)
 
 # Compiler Settings
 CC=clang
-#CC_OPTIONS = -O3 -flto -g -pthread -D_GNU_SOURCE
+CC_OPTIONS = -O3 -flto -g -pthread -D_GNU_SOURCE
 
 # CC_OPTIONS for Debugging
-CC_OPTIONS = -O0 -g -pthread -D_GNU_SOURCE
+#CC_OPTIONS = -O0 -g -pthread -D_GNU_SOURCE
 
 # CFI Sanitizer
 # CC_OPTIONS = -O0 -g -pthread -D_GNU_SOURCE -flto -fvisibility=default -fsanitize=cfi 
diff --git a/runtime/include/sandbox_functions.h b/runtime/include/sandbox_functions.h
index ebe32c8..2d39d8a 100644
--- a/runtime/include/sandbox_functions.h
+++ b/runtime/include/sandbox_functions.h
@@ -166,8 +166,6 @@ sandbox_print_perf(struct sandbox *sandbox)
 	if (runtime_sandbox_perf_log == NULL) return;
 
 	uint32_t total_time_us = sandbox->total_time / runtime_processor_speed_MHz;
-	uint32_t execution_time_ms = (sandbox->completion_timestamp - sandbox->start_execution_timestamp)
-					/ runtime_processor_speed_MHz;
 	uint32_t queued_us     = (sandbox->allocation_timestamp - sandbox->enqueue_timestamp)
 	                     / runtime_processor_speed_MHz;
 	uint32_t initializing_us = sandbox->initializing_duration / runtime_processor_speed_MHz;
@@ -181,9 +179,8 @@ sandbox_print_perf(struct sandbox *sandbox)
 	 * becomes more intelligent, then peak linear memory size needs to be tracked
 	 * seperately from current linear memory size.
 	 */
-	fprintf(runtime_sandbox_perf_log, "%lu,%s():%d,%s,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u\n", sandbox->id,
+	fprintf(runtime_sandbox_perf_log, "%lu,%s():%d,%s,%u,%u,%u,%u,%u,%u,%u,%u,%u\n", sandbox->id,
 	        sandbox->module->name, sandbox->module->port, sandbox_state_stringify(sandbox->state),
 	        sandbox->module->relative_deadline_us, total_time_us, queued_us, initializing_us, runnable_us,
-	        running_us, blocked_us, returned_us, execution_time_ms, sandbox->linear_memory_size);
-	fflush(runtime_sandbox_perf_log);
+	        running_us, blocked_us, returned_us, sandbox->linear_memory_size);
 }
diff --git a/runtime/include/sandbox_types.h b/runtime/include/sandbox_types.h
index 343d814..9cf510a 100644
--- a/runtime/include/sandbox_types.h
+++ b/runtime/include/sandbox_types.h
@@ -51,7 +51,6 @@ struct sandbox {
 
 	uint64_t request_arrival_timestamp;   /* Timestamp when request is received */
 	uint64_t enqueue_timestamp;   /* Timestamp when sandbox request is enqueued */
-	uint64_t start_execution_timestamp;   /* Timestamp when sandbox starts execution */
 	uint64_t allocation_timestamp;        /* Timestamp when sandbox is allocated */
 	uint64_t response_timestamp;          /* Timestamp when response is sent */
 	uint64_t completion_timestamp;        /* Timestamp when sandbox runs to completion */
diff --git a/runtime/src/current_sandbox.c b/runtime/src/current_sandbox.c
index 864de71..bc2acb2 100644
--- a/runtime/src/current_sandbox.c
+++ b/runtime/src/current_sandbox.c
@@ -61,11 +61,9 @@ current_sandbox_disable_preemption(struct sandbox *sandbox)
 void
 current_sandbox_start(void)
 {
-	uint64_t start_execution_timestamp =  __getcycles();
 	struct sandbox *sandbox = current_sandbox_get();
 	assert(sandbox != NULL);
 	assert(sandbox->state == SANDBOX_RUNNING);
-	sandbox->start_execution_timestamp = start_execution_timestamp;
 
 	char *error_message = "";
 
diff --git a/runtime/src/main.c b/runtime/src/main.c
index e527699..0729edf 100644
--- a/runtime/src/main.c
+++ b/runtime/src/main.c
@@ -225,7 +225,7 @@ runtime_configure()
 		runtime_sandbox_perf_log = fopen(runtime_sandbox_perf_log_path, "w");
 		if (runtime_sandbox_perf_log == NULL) { perror("sandbox perf log"); }
 		fprintf(runtime_sandbox_perf_log, "id,function,state,deadline,actual,queued,initializing,runnable,"
-		                                  "running,blocked,returned,execution,memory\n");
+		                                  "running,blocked,returned,memory\n");
 		fflush(runtime_sandbox_perf_log);
 	} else {
 		printf("\tSandbox Performance Log: Disabled\n");
diff --git a/runtime/tests/Makefile.inc b/runtime/tests/Makefile.inc
index 079e7b2..c2a879f 100644
--- a/runtime/tests/Makefile.inc
+++ b/runtime/tests/Makefile.inc
@@ -3,8 +3,8 @@ ARCH := $(shell uname -m)
 CC=clang # Source -> Native
 WASMCC=wasm32-unknown-unknown-wasm-clang # Source -> WebAssembly
 
-# OPTFLAGS=-O3 -flto
-OPTFLAGS=-O0 -flto -g
+OPTFLAGS=-O3 -flto
+# OPTFLAGS=-O0 -flto -g
 MEMC_64=64bit_nix.c
 # MEMC_NO=no_protection.c
 # MEMC_GEN=generic.c