diff --git a/configs/dram/sweep.py b/configs/dram/sweep.py
index eb4c9b41e..8459f9d00 100644
--- a/configs/dram/sweep.py
+++ b/configs/dram/sweep.py
@@ -94,7 +94,7 @@ mem_range = AddrRange('256MB')
 system.mem_ranges = [mem_range]
 
 # do not worry about reserving space for the backing store
-mmap_using_noreserve = True
+system.mmap_using_noreserve = True
 
 # force a single channel to match the assumptions in the DRAM traffic
 # generator
@@ -145,8 +145,8 @@ burst_size = int((system.mem_ctrls[0].devices_per_rank.value *
 page_size = system.mem_ctrls[0].devices_per_rank.value * \
     system.mem_ctrls[0].device_rowbuffer_size.value
 
-# match the maximum bandwidth of the memory, the parameter is in ns
-# and we need it in ticks
+# match the maximum bandwidth of the memory, the parameter is in seconds
+# and we need it in ticks (ps)
 itt = system.mem_ctrls[0].tBURST.value * 1000000000000
 
 # assume we start at 0
diff --git a/util/dram_sweep_plot.py b/util/dram_sweep_plot.py
index 8a752127c..f3fc32960 100755
--- a/util/dram_sweep_plot.py
+++ b/util/dram_sweep_plot.py
@@ -38,10 +38,8 @@
 # Authors: Andreas Hansson
 
 try:
-
     from mpl_toolkits.mplot3d import Axes3D
     from matplotlib import cm
-    from matplotlib.ticker import LinearLocator, FormatStrFormatter
     import matplotlib.pyplot as plt
     import numpy as np
 except ImportError:
@@ -74,13 +72,13 @@ def main():
     try:
         stats = open(sys.argv[2] + '/stats.txt', 'r')
     except IOError:
-        print "Failed to open ", sys.argv[1] + '/stats.txt', " for reading"
+        print "Failed to open ", sys.argv[2] + '/stats.txt', " for reading"
         exit(-1)
 
     try:
         simout = open(sys.argv[2] + '/simout', 'r')
     except IOError:
-        print "Failed to open ", sys.argv[1] + '/simout', " for reading"
+        print "Failed to open ", sys.argv[2] + '/simout', " for reading"
         exit(-1)
 
     # Get the burst size, number of banks and the maximum stride from