diff --git a/simoop.c b/simoop.c
index f73bb64..193330f 100644
--- a/simoop.c
+++ b/simoop.c
@@ -66,7 +66,7 @@
 /* -r  seconds */
 static unsigned long runtime = 30;
 /* -c  usec */
-static unsigned long long cputime = 3000000;
+static unsigned long long cputime = 0;
 /* -f size of the files we create */
 static unsigned long long file_size = 64 * 1024 * 1024;
 /* -n number of files we create */
@@ -75,8 +75,6 @@
 static unsigned long read_size = 2 * 1024 * 1024;
 /* -W write size */
 static unsigned long write_size = 2 * 1024 * 1024;
-/* -T number of files to read */
-static unsigned long rw_threads = 8;
 /* -D number of threads running du */
 static int du_threads = 0;
 /* memory to allocate and use during each task */
@@ -84,30 +82,34 @@
 /* should we fsync sometimes? */
 static int funksync = 0;
 static int writethrough = 0;
+
 /* are we just appending bytes onto the ends of the working set files */
 static int append_mode = 0;
 static int truncate_original = 0;
+
 /* dont do any crc checks -I */
 static int ignore_crcs = 0;
+
 /* randomize the write size */
 static int oddsizes = 0;
+
 /* use odirect sometimes */
 static int odirect = 0;
 
 /* check contents at startup */
 static int check_initial_files = 0;
+
 /* verify files immediately after writing */
 static int verify_writes = 0;
 
-
 /* -M how much memory we allocate to benchmark allocations */
-static unsigned long mmap_size = 64 * 1024 * 1024;
+static unsigned long mmap_size = 0;
 
 /* these do nothing but spin */
-static int cpu_threads = 24;
+static int cpu_threads = 0;
 
 /* how long we sleep while processing requests */
-static int sleeptime = 10000;
+static int sleeptime = 0;
 
 /* should we use fallocate instead of writing initial file contents */
 static int zallocate = 0;
@@ -463,7 +465,7 @@
 	return ret;
 }
 
-char *option_string = "t:s:C:c:r:n:f:FR:T:m:W:M:w:i:D:oaOVzNIev";
+char *option_string = "t:s:C:c:r:n:f:FR:T:m:W:M:w:i:D:oaOVzNIevU";
 static struct option long_options[] = {
 	{"appendmode", required_argument, 0, 'a'},
 	{"mmapsize", required_argument, 0, 'M'},
@@ -499,22 +501,21 @@
 	fprintf(stderr, "simoop usage:\n"
 		"\t-a (--appendmode): append onto working files\n"
 		"\t-t (--threads): worker threads (def: 16)\n"
-		"\t-m (--memory): memory to allocate during think time in each worker (def 128m)\n"
-		"\t-M (--mmapsize): amount to mmap to time allocator (64M)\n"
+		"\t-m (--memory): memory to allocate during think time in each worker (def 0)\n"
+		"\t-M (--mmapsize): amount to mmap to time allocator (def 0)\n"
 		"\t-r (--runtime): How long to run before exiting (seconds, def: 30)\n"
 		"\t-w (--warmuptime): How long to warmup before resetting the stats (seconds, def: 60)\n"
 		"\t-i (--interval): Sleep time in seconds between latency reports (sec, def: 120\n"
 		"\t-I (--ignorecrcs): don't verify crcs\n"
 		"\t-v (--verify-writes): immediately verify files written (def: no)\n"
 		"\t-V (--verify-startup): Verify all files on startup (def: no)\n"
-		"\t-s (--sleeptime): Sleep time in usecs between worker loops (usec, def: 10000\n"
-		"\t-c (--cputime): How long to think during each worker loop (seconds, def: 3)\n"
-		"\t-C (--cputhreads): How many threads do the cpu time loop (24)\n"
+		"\t-s (--sleeptime): Sleep time in usecs between worker loops (usec, def: 0\n"
+		"\t-c (--cputime): How long to think during each worker loop (seconds, def: 0)\n"
+		"\t-C (--cputhreads): How many threads do the cpu time loop (0)\n"
 		"\t-n (--numfiles): Number of files per directory tree (65536)\n"
 		"\t-f (--filesize): Size of each file (64M)\n"
 		"\t-R (--readsize): amount to read from each file (2M)\n"
 		"\t-W (--writesize): amount to write to tmp files (2M)\n"
-		"\t-T (--rwthreads): how many threads to read/write (8)\n"
 		"\t-D (--duthraeds): how many threads to scanning the working dirs (0)\n"
 		"\t-F (--funksync): fsync sometimes\n"
 		"\t-o (--oddsizes): randomize sizes to unaligned values\n"
@@ -602,9 +603,6 @@
 			write_size = parse_size(optarg);
 			write_size = verify_align_up(write_size);
 			break;
-		case 'T':
-			rw_threads = atoi(optarg);
-			break;
 		case 'D':
 			du_threads = atoi(optarg);
 			break;
@@ -1590,72 +1588,20 @@
 	free(tids);
 }
 
-void *read_thread(void *arg)
+void read_one(char *buf)
 {
-	int i;
-	char *buf = arg;
-
-	for (i = 0; i < 128; i++) {
-		int index = rand() % total_paths;
-		int seq = rand() % num_files;
-		char *path = paths[index];
-		read_from_file(path, seq, buf);
-		if (stopping)
-			break;
-	}
-	return NULL;
+	int index = rand() % total_paths;
+	int seq = rand() % num_files;
+	char *path = paths[index];
+	read_from_file(path, seq, buf);
 }
 
-/* startup reader threads, returns the tids for later waiting */
-void read_some_files(char *buf, pthread_t *tids)
+void write_one(char *buf)
 {
-	unsigned long i;
-	int ret;
-
-	for (i = 0; i < rw_threads; i++) {
-		pthread_t tid;
-		ret = pthread_create(&tid, NULL, read_thread,
-				     buf + i * read_size);
-		if (ret) {
-			fprintf(stderr, "error %d from pthread_create\n", ret);
-			exit(1);
-		}
-		tids[i] = tid;
-	}
-}
-
-void *write_thread(void *arg)
-{
-	char *buf = arg;
-	int i;
-
-	for (i = 0; i < 128; i++) {
-		int index = rand() % total_paths;
-		int seq = rand() % num_files;
-		char *path = paths[index];
-		write_to_file(path, seq, buf);
-		if (stopping)
-			break;
-	}
-	return NULL;
-}
-
-/* startup writer threads, returns the tids for later waiting */
-void write_some_files(char *buf, pthread_t *tids)
-{
-	unsigned long i;
-	int ret;
-
-	for (i = 0; i < rw_threads; i++) {
-		pthread_t tid;
-		ret = pthread_create(&tid, NULL, write_thread,
-				     buf + i * write_size);
-		if (ret) {
-			fprintf(stderr, "error %d from pthread_create\n", ret);
-			exit(1);
-		}
-		tids[i] = tid;
-	}
+	int index = rand() % total_paths;
+	int seq = rand() % num_files;
+	char *path = paths[index];
+	write_to_file(path, seq, buf);
 }
 
 char *aligned_memory_alloc(unsigned long size)
@@ -1695,20 +1641,16 @@
 	char *read_buf = NULL;
 	char *write_buf = NULL;
 	char *mem = NULL;
-	pthread_t *read_tids;
-	pthread_t *write_tids;
 	char *mmap_ptr;
 	int warmup_zerod = 0;
 	unsigned long i;
 
-	read_tids = malloc(sizeof(*read_tids) * rw_threads);
-	write_tids = malloc(sizeof(*write_tids) * rw_threads);
-	if (thinking_mem)
+	if (thinking_mem) {
 		mem = malloc(thinking_mem);
-
-	if (!read_tids || !write_tids || (thinking_mem && !mem)) {
-		perror("allocation failed\n");
-		exit(1);
+		if (!mem) {
+			perror("allocation failed\n");
+			exit(1);
+		}
 	}
 
 	while(!stopping) {
@@ -1721,11 +1663,11 @@
 			warmup_zerod = 1;
 		}
 		if (read_size)
-			read_buf = aligned_memory_alloc(rw_threads * read_size);
+			read_buf = aligned_memory_alloc(read_size);
 		else
 			read_buf = NULL;
 		if (write_size)
-			write_buf = aligned_memory_alloc(rw_threads * write_size);
+			write_buf = aligned_memory_alloc(write_size);
 		else
 			write_buf = NULL;
 
@@ -1733,19 +1675,10 @@
 		if (thinking_mem)
 			memset(mem, 0, thinking_mem);
 
-		gettimeofday(&start, NULL);
-
 		/* Start the threads to read files */
 		if (read_size) {
-			read_some_files(read_buf, read_tids);
-
-			/* think in parallel */
-			usec_spin(cputime);
-
-			/* wait for our reads to finish */
-			for (i = 0; i < rw_threads; i++) {
-				pthread_join(read_tids[i], NULL);
-			}
+			gettimeofday(&start, NULL);
+			read_one(read_buf);
 			gettimeofday(&now, NULL);
 
 			/*
@@ -1759,10 +1692,7 @@
 		/* write out the (pretend) results */
 		if (write_size) {
 			gettimeofday(&start, NULL);
-			write_some_files(write_buf, write_tids);
-			for (i = 0; i < rw_threads; i++) {
-				pthread_join(write_tids[i], NULL);
-			}
+			write_one(write_buf);
 			gettimeofday(&now, NULL);
 			record_one_lat(&td->stats[WRITE_STATS], &start, &now);
 		}
@@ -1796,8 +1726,8 @@
 		}
 		usec_spin(cputime);
 
-		aligned_memory_free(read_buf, rw_threads * read_size);
-		aligned_memory_free(write_buf, rw_threads * write_size);
+		aligned_memory_free(read_buf, read_size);
+		aligned_memory_free(write_buf, write_size);
 		td->work_done++;
 
 		if (sleeptime)
@@ -1805,8 +1735,6 @@
 	}
 
 	free(mem);
-	free(read_tids);
-	free(write_tids);
 	return NULL;
 }
 
@@ -1897,7 +1825,7 @@
 	for (i = 0; i < TOTAL_STATS; i++) {
 		unsigned int p50 = 0, p95 = 0, p99 = 0;
 		calc_p99(&dest[i], &p50, &p95, &p99);
-		printf("%s (p50: %'d) (p95: %'d) (p99: %'d)\n",
+		printf("%s usec: (p50: %'d) (p95: %'d) (p99: %'d)\n",
 		       stat_labels[i], p50, p95, p99);
 	}
 }