diff --git a/collectors/cpustatMetric.go b/collectors/cpustatMetric.go
index f517300..28ae002 100644
--- a/collectors/cpustatMetric.go
+++ b/collectors/cpustatMetric.go
@@ -1,12 +1,15 @@
 package collectors
 
 import (
+	"bufio"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"strconv"
 	"strings"
 	"time"
+
+	cclog "github.com/ClusterCockpit/cc-metric-collector/internal/ccLogger"
 	lp "github.com/ClusterCockpit/cc-metric-collector/internal/ccMetric"
 )
 
@@ -18,72 +21,128 @@ type CpustatCollectorConfig struct {
 
 type CpustatCollector struct {
 	metricCollector
-	config CpustatCollectorConfig
+	config          CpustatCollectorConfig
+	matches         map[string]int
+	cputags         map[string]map[string]string
+	nodetags        map[string]string
+	num_cpus_metric lp.CCMetric
 }
 
 func (m *CpustatCollector) Init(config json.RawMessage) error {
 	m.name = "CpustatCollector"
 	m.setup()
-	m.meta = map[string]string{"source": m.name, "group": "CPU"}
+	m.meta = map[string]string{"source": m.name, "group": "CPU", "unit": "Percent"}
+	m.nodetags = map[string]string{"type": "node"}
 	if len(config) > 0 {
 		err := json.Unmarshal(config, &m.config)
 		if err != nil {
 			return err
 		}
 	}
+	matches := map[string]int{
+		"cpu_user":       1,
+		"cpu_nice":       2,
+		"cpu_system":     3,
+		"cpu_idle":       4,
+		"cpu_iowait":     5,
+		"cpu_irq":        6,
+		"cpu_softirq":    7,
+		"cpu_steal":      8,
+		"cpu_guest":      9,
+		"cpu_guest_nice": 10,
+	}
+
+	m.matches = make(map[string]int)
+	for match, index := range matches {
+		doExclude := false
+		for _, exclude := range m.config.ExcludeMetrics {
+			if match == exclude {
+				doExclude = true
+				break
+			}
+		}
+		if !doExclude {
+			m.matches[match] = index
+		}
+	}
+
+	// Check input file
+	file, err := os.Open(string(CPUSTATFILE))
+	if err != nil {
+		cclog.ComponentError(m.name, err.Error())
+	}
+	defer file.Close()
+
+	// Pre-generate tags for all CPUs
+	num_cpus := 0
+	m.cputags = make(map[string]map[string]string)
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		linefields := strings.Fields(line)
+		if strings.HasPrefix(linefields[0], "cpu") && strings.Compare(linefields[0], "cpu") != 0 {
+			cpustr := strings.TrimLeft(linefields[0], "cpu")
+			cpu, _ := strconv.Atoi(cpustr)
+			m.cputags[linefields[0]] = map[string]string{"type": "cpu", "type-id": fmt.Sprintf("%d", cpu)}
+			num_cpus++
+		}
+	}
 	m.init = true
 	return nil
 }
 
-func (c *CpustatCollector) parseStatLine(line string, cpu int, exclude []string, output chan lp.CCMetric) {
-	ls := strings.Fields(line)
-	matches := []string{"", "cpu_user", "cpu_nice", "cpu_system", "cpu_idle", "cpu_iowait", "cpu_irq", "cpu_softirq", "cpu_steal", "cpu_guest", "cpu_guest_nice"}
-	for _, ex := range exclude {
-		matches, _ = RemoveFromStringList(matches, ex)
-	}
-
-	var tags map[string]string
-	if cpu < 0 {
-		tags = map[string]string{"type": "node"}
-	} else {
-		tags = map[string]string{"type": "cpu", "type-id": fmt.Sprintf("%d", cpu)}
-	}
-	for i, m := range matches {
-		if len(m) > 0 {
-			x, err := strconv.ParseInt(ls[i], 0, 64)
+func (m *CpustatCollector) parseStatLine(linefields []string, tags map[string]string, output chan lp.CCMetric) {
+	values := make(map[string]float64)
+	total := 0.0
+	for match, index := range m.matches {
+		if len(match) > 0 {
+			x, err := strconv.ParseInt(linefields[index], 0, 64)
 			if err == nil {
-				y, err := lp.New(m, tags, c.meta, map[string]interface{}{"value": int(x)}, time.Now())
-				if err == nil {
-					output <- y
-				}
+				values[match] = float64(x)
+				total += values[match]
 			}
 		}
 	}
+	t := time.Now()
+	for name, value := range values {
+		y, err := lp.New(name, tags, m.meta, map[string]interface{}{"value": (value * 100.0) / total}, t)
+		if err == nil {
+			output <- y
+		}
+	}
 }
 
 func (m *CpustatCollector) Read(interval time.Duration, output chan lp.CCMetric) {
 	if !m.init {
 		return
 	}
-	buffer, err := ioutil.ReadFile(string(CPUSTATFILE))
-
+	num_cpus := 0
+	file, err := os.Open(string(CPUSTATFILE))
 	if err != nil {
-		return
+		cclog.ComponentError(m.name, err.Error())
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		linefields := strings.Fields(line)
+		if strings.Compare(linefields[0], "cpu") == 0 {
+			m.parseStatLine(linefields, m.nodetags, output)
+		} else if strings.HasPrefix(linefields[0], "cpu") {
+			m.parseStatLine(linefields, m.cputags[linefields[0]], output)
+			num_cpus++
+		}
 	}
 
-	ll := strings.Split(string(buffer), "\n")
-	for _, line := range ll {
-		if len(line) == 0 {
-			continue
-		}
-		ls := strings.Fields(line)
-		if strings.Compare(ls[0], "cpu") == 0 {
-			m.parseStatLine(line, -1, m.config.ExcludeMetrics, output)
-		} else if strings.HasPrefix(ls[0], "cpu") {
-			cpustr := strings.TrimLeft(ls[0], "cpu")
-			cpu, _ := strconv.Atoi(cpustr)
-			m.parseStatLine(line, cpu, m.config.ExcludeMetrics, output)
-		}
+	num_cpus_metric, err := lp.New("num_cpus",
+		m.nodetags,
+		m.meta,
+		map[string]interface{}{"value": int(num_cpus)},
+		time.Now(),
+	)
+	if err == nil {
+		output <- num_cpus_metric
 	}
 }