diff --git a/main.go b/main.go
index 3850585..590ad39 100644
--- a/main.go
+++ b/main.go
@@ -38,7 +38,7 @@ var (
 	zoomInterval = 3
 
 	averageLoad = false
-	percpuLoad = false
+	percpuLoad  = false
 
 	cpu  *w.CPU
 	mem  *w.Mem
@@ -60,6 +60,8 @@ Options:
   -m, --minimal         Only show CPU, Mem and Process widgets.
   -r, --rate=RATE       Number of times per second to update CPU and Mem widgets [default: 1].
   -v, --version         Show version.
+  -p, --percpu          Show each CPU in the CPU widget.
+  -a, --averagecpu      Show average CPU in the CPU widget.
 
 Colorschemes:
   default
@@ -86,6 +88,9 @@ Colorschemes:
 	} else {
 		interval = time.Second / time.Duration(rate)
 	}
+
+	averageLoad, _ = args["--averagecpu"].(bool)
+	percpuLoad, _ = args["--percpu"].(bool)
 }
 
 func handleColorscheme(cs string) {
diff --git a/src/widgets/cpu.go b/src/widgets/cpu.go
index c35782c..573eede 100644
--- a/src/widgets/cpu.go
+++ b/src/widgets/cpu.go
@@ -4,15 +4,16 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/cjbassi/gotop/src/utils"
 	ui "github.com/cjbassi/termui"
 	psCPU "github.com/shirou/gopsutil/cpu"
 )
 
 type CPU struct {
 	*ui.LineGraph
-	Count    int // number of cores
-	Average bool // show average load
-	PerCPU bool // show per-core load
+	Count    int  // number of cores
+	Average  bool // show average load
+	PerCPU   bool // show per-core load
 	interval time.Duration
 }
 
@@ -49,7 +50,8 @@ func NewCPU(interval time.Duration, zoom int, average bool, percpu bool) *CPU {
 
 	ticker := time.NewTicker(self.interval)
 	go func() {
-		self.update()
+		// update asynchronously because of 1 second blocking period
+		go self.update()
 		for range ticker.C {
 			self.update()
 		}
@@ -68,6 +70,17 @@ func (self *CPU) update() {
 
 	if self.PerCPU {
 		percents, _ := psCPU.Percent(self.interval, true)
+		if len(percents) != self.Count {
+			count, _ := psCPU.Counts(false)
+			utils.Error("CPU percentages",
+				fmt.Sprint(
+					"self.Count: ", self.Count, "\n",
+					"gopsutil.Counts(): ", count, "\n",
+					"len(percents): ", len(percents), "\n",
+					"percents: ", percents, "\n",
+					"self.interval: ", self.interval,
+				))
+		}
 		for i := 0; i < self.Count; i++ {
 			k := fmt.Sprintf("CPU%d", i)
 			self.Data[k] = append(self.Data[k], percents[i])