diff --git a/html/ops/credit_study.php b/html/ops/credit_study.php
new file mode 100644
index 0000000000..5d32ecd775
--- /dev/null
+++ b/html/ops/credit_study.php
@@ -0,0 +1,109 @@
+<?php
+
+// Use this script to find an optimal value for fp_benchmark_weight.
+// This evaluates the variation for weights 0, .1, ... 1.
+
+require_once("../inc/db.inc");
+
+db_init();
+
+function mean($x) {
+    $sum = 0;
+    $n = count($x);
+    for ($i=0; $i<$n; $i++) {
+        $sum += $x[$i];
+    }
+    return $sum/$n;
+}
+
+function spread($x) {
+    $sum = 0;
+    $n = count($x);
+    $m = mean($x);
+    for ($i=0; $i<$n; $i++) {
+        $d = $x[$i] - $m;
+        $sum += $d*$d;
+    }
+    return sqrt($sum)/$n;
+}
+
+function cc($x, $fpw) {
+    $cps = $x->p_fpops*$fpw + $x->p_iops*(1-$fpw);
+    $cps /= 1e9;
+    $cps /= 864;
+    $cc = $x->cpu_time * $cps;
+    //if ($x->duration_correction_factor) {
+    //    $cc /= $x->duration_correction_factor;
+    //}
+    return $cc;
+}
+
+// $x is a vector of objects
+//
+function handle_wu($x) {
+    $cc = array();
+    for ($i=0; $i<=12; $i++) {
+        array_push($cc, array());
+    }
+    for ($j=0; $j<count($x); $j++) {
+        $y = $x[$j];
+        for ($i=0; $i<=12; $i++) {
+            $r = $i/10.;
+            array_push($cc[$i], cc($y, $r));
+        }
+    }
+    $res = array();
+    for ($i=0; $i<=12; $i++) {
+        $c = $cc[$i];
+        $m = mean($c);
+        $s = spread($c);
+        $rs = $s/$m;
+        array_push($res, $rs);
+    }
+    return $res;
+}
+
+function get_data() {
+    $sum = array();
+    for ($i=0; $i<=12; $i++) {
+        array_push($sum, 0);
+    }
+    $r1 = mysql_query(
+        "select id from workunit where canonical_resultid>0 limit 10000"
+    );
+    $n = 0;
+    while ($wu = mysql_fetch_object($r1)) {
+        $x = array();
+        $r2 = mysql_query("select * from result where workunitid=$wu->id");
+        $found_zero = false;
+        while ($result = mysql_fetch_object($r2)) {
+            if ($result->granted_credit==0) continue;
+            if ($result->claimed_credit==0) $found_zero = true;
+            $host = lookup_host($result->hostid);
+            $y->claimed_credit = $result->claimed_credit;
+            $y->granted_credit = $result->granted_credit;
+            $y->cpu_time = $result->cpu_time;
+            $y->p_fpops = $host->p_fpops;
+            $y->p_iops = $host->p_iops;
+            $y->duration_correction_factor = $host->duration_correction_factor;
+            $y->id = $result->id;
+            array_push($x, $y);
+        }
+        if (count($x)==0) continue;
+        if ($found_zero) continue;
+        $res = handle_wu($x);
+        for ($i=0; $i<=12; $i++) {
+            $sum[$i] += $res[$i];
+        }
+        $n++;
+    }
+    for ($i=0; $i<=12; $i++) {
+        $r = $sum[$i]/$n;
+        echo "$i $r\n";
+    }
+}
+
+
+get_data();
+
+?>