diff --git a/garlic/apps/fwi/default.nix b/garlic/apps/fwi/default.nix
index 013fcef..5b1a9d6 100644
--- a/garlic/apps/fwi/default.nix
+++ b/garlic/apps/fwi/default.nix
@@ -34,6 +34,7 @@ stdenv.mkDerivation rec {
   # FIXME: Allow multiple MPI implementations
   postPatch = ''
     sed -i 's/= OPENMPI$/= INTEL/g' Makefile
+    sed -i 's/USE_O_DIRECT ?= NO/USE_O_DIRECT ?= YES/g' Makefile || true
   '';
 
   # FIXME: This is an ugly hack.
diff --git a/garlic/exp/fwi/data_reuse.nix b/garlic/exp/fwi/data_reuse.nix
index 623492a..84f0c4b 100644
--- a/garlic/exp/fwi/data_reuse.nix
+++ b/garlic/exp/fwi/data_reuse.nix
@@ -1,3 +1,23 @@
+# This test compares a FWI version using poor data locality (+NOREUSE) versus
+# the optimized version (used for all other experiments). Follows a pseudocode
+# snippet illustrating the fundamental difference between version.
+#
+# NOREUSE
+# ----------------------
+# for (y) for (x) for (z)
+#   computA(v[y][x][z]);
+# for (y) for (x) for (z)
+#   computB(v[y][x][z]);
+# for (y) for (x) for (z)
+#   computC(v[y][x][z]);
+#
+# Optimized version
+# ----------------------
+# for (y) for (x) for (z)
+#   computA(v[y][x][z]);
+#   computB(v[y][x][z]);
+#   computC(v[y][x][z]);
+
 {
   stdenv
 , stdexp
@@ -15,34 +35,14 @@ let
   # Initial variable configuration
   varConf = {
     gitBranch = [
-#      "garlic/tampi+send+oss+task"
-#      "garlic/mpi+send+omp+task"
        "garlic/mpi+send+oss+task"
-       "garlic/mpi+send+oss+task+noreuse"
-#      "garlic/mpi+send+seq"
-#      "garlic/oss+task"
-#      "garlic/omp+task"
-#      "garlic/seq"
+       "garlic/mpi+send+oss+task+NOREUSE"
     ];
 
     blocksize = [ 1 2 4 8 ];
-    #blocksize = [ 1 2 ];
 
     n = [
-#   	{nx=50;  ny=4000; nz=50;}
-#   	{nx=20;  ny=4000; nz=20;}
-#    	{nx=300; ny=8000; nz=300;} # half node, /
-#    	{nx=300; ny=1000; nz=300;} # half node, /
-#    	{nx=200; ny=1000; nz=200;} # half node, not enough tasks
-#    	{nx=200; ny=4000; nz=200;} # --/ half node
-#    	{nx=250; ny=2000; nz=250;} # / half node
     	{nx=300; ny=2000; nz=300;} # / half node
-#    	{nx=100; ny=2000; nz=100;} # \-// half node
-#    	{nx=150; ny=2000; nz=150;} # \-/ half node
-#	{nx=200; ny=64000; nz=200;} # --/ 16 nodes
-#    	{nx=200; ny=4000; nz=200;} # --/ half node
-#    	{nx=200; ny=8000; nz=200;} # --/ 1 node
-#    	{nx=100; ny=8000; nz=100;} # --/ half node
     ];
   };
 
diff --git a/garlic/exp/fwi/granularity.nix b/garlic/exp/fwi/granularity.nix
index 1c8cac4..7773b3b 100644
--- a/garlic/exp/fwi/granularity.nix
+++ b/garlic/exp/fwi/granularity.nix
@@ -1,3 +1,5 @@
+# Regular granularity test for FWI
+
 {
   stdenv
 , stdexp
@@ -15,20 +17,20 @@ let
   # Initial variable configuration
   varConf = {
     gitBranch = [
-       "garlic/tampi+send+oss+task"
-       "garlic/tampi+isend+oss+task"
-       "garlic/mpi+send+omp+task"
-       "garlic/mpi+send+oss+task"
+#      "garlic/tampi+send+oss+task"
+      "garlic/tampi+isend+oss+task"
+#      "garlic/mpi+send+omp+task"
+#      "garlic/mpi+send+oss+task"
 #      "garlic/mpi+send+seq"
 #      "garlic/oss+task"
 #      "garlic/omp+task"
 #      "garlic/seq"
     ];
 
-    blocksize = [ 1 2 4 8 16 32 ];
+    blocksize = [ 1 2 4 8 16 32 64 128 256 ];
 
     n = [
-    	{nx=500; nz=500; ny=2000; ntpn=2; nn=1;}
+    	{nx=100; nz=100; ny=8000; ntpn=2; nn=1;}
     ];
 
   };
diff --git a/garlic/exp/fwi/memory_affinity.nix b/garlic/exp/fwi/memory_affinity.nix
deleted file mode 100644
index 3df7226..0000000
--- a/garlic/exp/fwi/memory_affinity.nix
+++ /dev/null
@@ -1,138 +0,0 @@
-{
-  stdenv
-, stdexp
-, bsc
-, targetMachine
-, stages
-}:
-
-with stdenv.lib;
-
-let
-
-  inherit (targetMachine) fs;
-
-  # Initial variable configuration
-  varConf = {
-    gitBranch = [
-#      "garlic/tampi+send+oss+task"
-#      "garlic/mpi+send+omp+task"
-       "garlic/mpi+send+oss+task"
-#      "garlic/mpi+send+seq"
-#      "garlic/oss+task"
-#      "garlic/omp+task"
-#      "garlic/seq"
-    ];
-
-    blocksize = [ 1 ];
-
-    n = [
-#       {nx=500; nz=500; ny=8000;}
-        {nx=500; nz=500; ny=2000;}
-    ];
-
-    nodes = [ 1 ]
-
-    numactl = [ true false ]
-
-  };
-
-# The c value contains something like:
-# {
-#   n = { nx=500; ny=500; nz=500; }
-#   blocksize = 1;
-#   gitBranch = "garlic/tampi+send+oss+task";
-# }
-
-  machineConfig = targetMachine.config;
-
-  # Generate the complete configuration for each unit
-  genConf = with bsc; c: targetMachine.config // rec {
-    expName = "fwi";
-    unitName = "${expName}-test";
-    inherit (machineConfig) hw;
-
-    cc = icc;
-    inherit (c) gitBranch blocksize;
-    useNumactl = c.numactl
-
-    #nx = c.n.nx;
-    #ny = c.n.ny;
-    #nz = c.n.nz;
-
-    # Same but shorter:
-    inherit (c.n) nx ny nz;
-
-    fwiInput = bsc.apps.fwi.input.override {
-      inherit (c.n) nx ny nz;
-    };
-
-    # Other FWI parameters
-    ioFreq = -1;
-
-    # Repeat the execution of each unit several times
-    loops = 10;
-    #loops = 1;
-
-    # Resources
-    cpusPerTask = if (useNumactl) then hw.cpusPerNode else hw.cpusPerSocket;
-    ntasksPerNode = hw.cpusPerNode / cpusPerTask;
-    nodes = c.nodes;
-    qos = "debug";
-    time = "02:00:00";
-    jobName = unitName;
-
-    tracing = "no";
-
-    # Enable permissions to write in the local storage
-    extraMounts = [ fs.local.temp ];
-
-  };
-
-  # Compute the array of configurations
-  configs = stdexp.buildConfigs {
-    inherit varConf genConf;
-  };
-
-  exec = {nextStage, conf, ...}: stages.exec ({
-    inherit nextStage;
-    pre = ''
-      CDIR=$PWD
-      if [[ "${conf.tracing}" == "yes" ]]; then
-          export NANOS6_CONFIG_OVERRIDE="version.instrument=ctf"
-      fi
-      EXECDIR="${fs.local.temp}/out/$GARLIC_USER/$GARLIC_UNIT/$GARLIC_RUN"
-      mkdir -p $EXECDIR
-      cd $EXECDIR
-      ln -fs ${conf.fwiInput}/InputModels InputModels || true
-    '';
-    argv = [
-      "${conf.fwiInput}/fwi_params.txt"
-      "${conf.fwiInput}/fwi_frequencies.txt"
-      conf.blocksize
-      "-1" # Fordward steps
-      "-1" # Backward steps
-      conf.ioFreq # Write/read frequency
-    ];
-    post = ''
-      rm -rf Results || true
-      if [[ "${conf.tracing}" == "yes" ]]; then
-          mv trace_* $CDIR
-      fi
-    '';
-  } // optionalAttrs (conf.useNumact) {
-    program = "${numactl}/bin/numactl --interleave=all ${stageProgram nextStage}";
-  });
-
-  apps = bsc.garlic.apps;
-
-  # FWI program
-  program = {nextStage, conf, ...}: apps.fwi.solver.override {
-    inherit (conf) cc gitBranch fwiInput;
-  };
-
-  pipeline = stdexp.stdPipeline ++ [ exec program ];
-
-in
- 
-  stdexp.genExperiment { inherit configs pipeline; }
diff --git a/garlic/exp/fwi/strong_scaling_forkjoin.nix b/garlic/exp/fwi/strong_scaling_forkjoin.nix
index 8ff84c2..902eaf6 100644
--- a/garlic/exp/fwi/strong_scaling_forkjoin.nix
+++ b/garlic/exp/fwi/strong_scaling_forkjoin.nix
@@ -1,3 +1,6 @@
+# Strong scaling test for FWI variants based on forkjoint. This
+# experiment does not rely on block sizes.
+
 {
   stdenv
 , stdexp
@@ -15,20 +18,13 @@ let
   # Initial variable configuration
   varConf = {
     gitBranch = [
-#      "garlic/tampi+send+oss+task"
-#      "garlic/mpi+send+omp+task"
-#      "garlic/mpi+send+oss+task"
        "garlic/mpi+send+omp+fork"
-#      "garlic/mpi+send+seq"
-#      "garlic/oss+task"
-#      "garlic/omp+task"
-#      "garlic/seq"
     ];
 
     blocksize = [ 0 ];
 
     n = [
-        {nx=500; nz=500; ny=16000;}
+        {nx=100; nz=100; ny=8000;}
     ];
 
     nodes = [ 1 2 4 8 16 ];
diff --git a/garlic/exp/fwi/strong_scaling_io.nix b/garlic/exp/fwi/strong_scaling_io.nix
index 30f0e75..c063659 100644
--- a/garlic/exp/fwi/strong_scaling_io.nix
+++ b/garlic/exp/fwi/strong_scaling_io.nix
@@ -1,3 +1,10 @@
+# Strong scaling test for FWI variants based on tasks with and without I/O.
+# This experiment solves a computationally expensive input which brings the
+# storage devices to saturation when I/O is enabled.  the same input us run
+# without I/O for comparison purposes..  Also, the experiments are runt for a
+# range of block sizes deemed as efficient according to the granularity
+# experiment.
+
 {
   stdenv
 , stdexp
diff --git a/garlic/exp/fwi/strong_scaling_mpionly.nix b/garlic/exp/fwi/strong_scaling_mpionly.nix
index 48283cb..94ffd8d 100644
--- a/garlic/exp/fwi/strong_scaling_mpionly.nix
+++ b/garlic/exp/fwi/strong_scaling_mpionly.nix
@@ -1,3 +1,7 @@
+# Strong scaling test for FWI variants based exclusively on MPI. This
+# experiment does not rely on block sizes. An MPI process is instantiated per
+# core.
+
 {
   stdenv
 , stdexp
@@ -15,24 +19,17 @@ let
   # Initial variable configuration
   varConf = {
     gitBranch = [
-#      "garlic/tampi+send+oss+task"
-#      "garlic/mpi+send+omp+task"
-#      "garlic/mpi+send+oss+task"
-#      "garlic/mpi+send+omp+fork"
        "garlic/mpi+send+seq"
-#      "garlic/oss+task"
-#      "garlic/omp+task"
-#      "garlic/seq"
     ];
 
     blocksize = [ 0 ];
 
     n = [
-        {nx=500; nz=500; ny=16000;}
+        {nx=100; nz=100; ny=8000;}
     ];
 
-    # Not enough planes for 8 and 16 nodes
-    nodes = [ 1 2 4 ];
+    # Not enough planes for 4, 8 and 16 nodes
+    nodes = [ 1 2 ];
 
   };
 
diff --git a/garlic/exp/fwi/strong_scaling_task.nix b/garlic/exp/fwi/strong_scaling_task.nix
index 048fe7e..4ad7833 100644
--- a/garlic/exp/fwi/strong_scaling_task.nix
+++ b/garlic/exp/fwi/strong_scaling_task.nix
@@ -1,3 +1,7 @@
+# Strong scaling test for FWI variants based on tasks. This
+# experiment explores a range of block sizes deemed as efficient
+# according to the granularity experiment.
+
 {
   stdenv
 , stdexp
@@ -19,16 +23,12 @@ let
        "garlic/tampi+isend+oss+task"
        "garlic/mpi+send+omp+task"
        "garlic/mpi+send+oss+task"
-#      "garlic/mpi+send+seq"
-#      "garlic/oss+task"
-#      "garlic/omp+task"
-#      "garlic/seq"
     ];
 
-    blocksize = [ 1 2 4 8 ];
+    blocksize = [ 1 2 4 8 16 ];
 
     n = [
-        {nx=500; nz=500; ny=16000;}
+        {nx=100; nz=100; ny=8000;}
     ];
 
     nodes = [ 1 2 4 8 16 ];
diff --git a/garlic/exp/fwi/test.nix b/garlic/exp/fwi/sync_io.nix
similarity index 84%
rename from garlic/exp/fwi/test.nix
rename to garlic/exp/fwi/sync_io.nix
index a9ea312..59e791d 100644
--- a/garlic/exp/fwi/test.nix
+++ b/garlic/exp/fwi/sync_io.nix
@@ -1,3 +1,7 @@
+# This experiment compares the effect of not using I/O versus using O_DIRECT |
+# O_DSYNC enabled I/O. This is a reduced version of the strong_scaling_io
+# experiment.
+
 {
   stdenv
 , stdexp
@@ -15,8 +19,8 @@ let
   # Initial variable configuration
   varConf = {
     gitBranch = [
-#      "garlic/tampi+send+oss+task"
-       "garlic/mpi+send+omp+task"
+       "garlic/tampi+send+oss+task"
+#      "garlic/mpi+send+omp+task"
 #      "garlic/mpi+send+oss+task"
 #      "garlic/mpi+send+seq"
 #      "garlic/oss+task"
@@ -24,14 +28,16 @@ let
 #      "garlic/seq"
     ];
 
-    blocksize = [ 1 2 4 8 16 32 ];
-    #blocksize = [ 1 2 4 8 ];
+    blocksize = [ 1 ];
 
     n = [
-    	#{nx=500; nz=500; ny=1000; ntpn=1; nn=1;}
-    	{nx=500; nz=500; ny=2000; ntpn=2; nn=1;}
+        {nx=500; nz=500; ny=16000;}
     ];
 
+    nodes = [ 4 ];
+
+    ioFreq = [ 9999 (-1) ];
+
   };
 
 # The c value contains something like:
@@ -57,14 +63,14 @@ let
     #nz = c.n.nz;
 
     # Same but shorter:
-    inherit (c.n) nx ny nz ntpn nn;
+    inherit (c.n) nx ny nz;
 
     fwiInput = bsc.apps.fwi.input.override {
       inherit (c.n) nx ny nz;
     };
 
     # Other FWI parameters
-    ioFreq = -1;
+    ioFreq = c.ioFreq;
 
     # Repeat the execution of each unit several times
     loops = 10;
@@ -72,8 +78,8 @@ let
 
     # Resources
     cpusPerTask = hw.cpusPerSocket;
-    ntasksPerNode = ntpn;
-    nodes = nn;
+    ntasksPerNode = 2;
+    nodes = c.nodes;
     qos = "debug";
     time = "02:00:00";
     jobName = unitName;
diff --git a/garlic/exp/index.nix b/garlic/exp/index.nix
index c50cdea..f6a518d 100644
--- a/garlic/exp/index.nix
+++ b/garlic/exp/index.nix
@@ -98,12 +98,13 @@
   };
 
   fwi = {
-    test                    = callPackage ./fwi/test.nix { };
+    granularity             = callPackage ./fwi/granularity.nix { };
     strong_scaling_task     = callPackage ./fwi/strong_scaling_task.nix { };
     strong_scaling_forkjoin = callPackage ./fwi/strong_scaling_forkjoin.nix { };
     strong_scaling_mpionly  = callPackage ./fwi/strong_scaling_mpionly.nix { };
+    data_reuse              = callPackage ./fwi/data_reuse.nix { };
     strong_scaling_io       = callPackage ./fwi/strong_scaling_io.nix { };
-    granularity             = callPackage ./fwi/granularity.nix { };
+    sync_io                 = callPackage ./fwi/sync_io.nix { };
   };
 
   osu = rec {
diff --git a/garlic/fig/fwi/granularity.R b/garlic/fig/fwi/granularity.R
index a1fc99d..40d6f75 100644
--- a/garlic/fig/fwi/granularity.R
+++ b/garlic/fig/fwi/granularity.R
@@ -30,7 +30,7 @@ w=5
 ####################################################################
 ### Line Graph
 ####################################################################
-png("time.png", width=w*ppi, height=h*ppi, res=ppi)
+png("mtime.png", width=w*ppi, height=h*ppi, res=ppi)
 
 ## Create the plot with the normalized time vs nblocks
 p = ggplot(df, aes(x = blocksize, y=mtime, group=gitBranch, color=gitBranch)) +
@@ -49,22 +49,23 @@ print(p)
 dev.off()
 
 ####################################################################
-### Boxplot
+### Line Graph
 ####################################################################
-png("box.png", width=w*ppi, height=h*ppi, res=ppi)
-# Create the plot with the normalized time vs nblocks
-p = ggplot(df, aes(x=blocksize, y=time, group=gitBranch, colour=gitBranch)) +
-        # Labels
-        labs(x="Blocksize", y="Normalized time",
-              title=sprintf("FWI Time"),
-              subtitle=input_file) +
-        # Draw boxplots
-        geom_boxplot() +
-        theme_bw() +
-        theme(plot.subtitle=element_text(size=8)) +
-        theme(legend.position = c(0.5, 0.88))
+png("time.png", width=w*ppi, height=h*ppi, res=ppi)
+
+## Create the plot with the normalized time vs nblocks
+p = ggplot(df, aes(x = blocksize, y=time, group=gitBranch, color=gitBranch)) +
+  geom_point() +
+  geom_line() +
+  theme_bw() +
+  labs(x="Blocksize", y="Time (s)", title="FWI granularity",
+    subtitle=input_file) +
+  theme(plot.subtitle=element_text(size=8)) +
+  theme(legend.position = c(0.5, 0.88))
+
 # Render the plot
 print(p)
-## Save the png image
+
+# Save the png image
 dev.off()
 
diff --git a/garlic/fig/fwi/strong_scaling.R b/garlic/fig/fwi/strong_scaling.R
index 5dd4bb5..89d79f1 100644
--- a/garlic/fig/fwi/strong_scaling.R
+++ b/garlic/fig/fwi/strong_scaling.R
@@ -14,7 +14,7 @@ dataset = jsonlite::stream_in(file(input_file)) %>%
   jsonlite::flatten()
 
 # Select block size to display
-useBlocksize = 1
+useBlocksize = 2
 
 # We only need the nblocks and time
 df = select(dataset, config.blocksize, config.gitBranch, config.nodes, time) %>%
@@ -59,7 +59,7 @@ print(p)
 dev.off()
 
 ####################################################################
-### Line plot (timei x nodes)
+### Line plot (time x nodes)
 ####################################################################
 png("nxtime.png", width=w*ppi, height=h*ppi, res=ppi)
 
diff --git a/garlic/fig/fwi/test.R b/garlic/fig/fwi/test.R
deleted file mode 100644
index ca79f0d..0000000
--- a/garlic/fig/fwi/test.R
+++ /dev/null
@@ -1,46 +0,0 @@
-library(ggplot2)
-library(dplyr)
-library(scales)
-library(jsonlite)
-
-args=commandArgs(trailingOnly=TRUE)
-
-# Read the timetable from args[1]
-input_file = "input.json"
-if (length(args)>0) { input_file = args[1] }
-
-# Load the dataset in NDJSON format
-dataset = jsonlite::stream_in(file(input_file)) %>%
-	jsonlite::flatten()
-
-# We only need the nblocks and time
-df = select(dataset, config.blocksize, config.gitBranch, time) %>%
-	rename(blocksize=config.blocksize, gitBranch=config.gitBranch) %>%
-  group_by(blocksize, gitBranch) %>%
-  mutate(mtime = median(time)) %>%
-  ungroup()
-
-df$gitBranch = as.factor(df$gitBranch)
-df$blocksize = as.factor(df$blocksize)
-
-ppi=300
-h=5
-w=5
-
-png("time.png", width=w*ppi, height=h*ppi, res=ppi)
-#
-## Create the plot with the normalized time vs nblocks
-p = ggplot(df, aes(x=blocksize, y=time)) +
-	geom_point() +
-	geom_line(aes(y=mtime, group=gitBranch, color=gitBranch)) +
-	theme_bw() +
-	labs(x="Blocksize", y="Time (s)", title="FWI granularity",
-    subtitle=input_file) +
-	theme(plot.subtitle=element_text(size=8)) +
-	theme(legend.position = c(0.5, 0.88))
-
-# Render the plot
-print(p)
-
-# Save the png image
-dev.off()
diff --git a/garlic/fig/index.nix b/garlic/fig/index.nix
index 5ca637f..b3f77ea 100644
--- a/garlic/fig/index.nix
+++ b/garlic/fig/index.nix
@@ -62,10 +62,12 @@ in
   };
 
   fwi = with exp.fwi; {
-    test              = stdPlot ./fwi/test.R [ test ];
-    strong_scaling    = stdPlot ./fwi/strong_scaling.R [ strong_scaling_task strong_scaling_forkjoin strong_scaling_mpionly ];
-    strong_scaling_io = stdPlot ./fwi/strong_scaling_io.R [ strong_scaling_io ];
     granularity       = stdPlot ./fwi/granularity.R [ granularity ];
+    strong_scaling    = stdPlot ./fwi/strong_scaling.R [ strong_scaling_task strong_scaling_forkjoin ];
+    #strong_scaling    = stdPlot ./fwi/strong_scaling.R [ strong_scaling_task strong_scaling_forkjoin strong_scaling_mpionly ];
+    data_reuse        = stdPlot ./fwi/granularity.R [ data_reuse ];
+    strong_scaling_io = stdPlot ./fwi/strong_scaling_io.R [ strong_scaling_io ];
+    sync_io           = stdPlot ./fwi/strong_scaling_io.R [ sync_io ];
   };
 
   osu = with exp.osu; {