diff --git a/pkg/downloader/protocol/http/fetcher.go b/pkg/downloader/protocol/http/fetcher.go
index d9ed596..d3db8d7 100644
--- a/pkg/downloader/protocol/http/fetcher.go
+++ b/pkg/downloader/protocol/http/fetcher.go
@@ -260,7 +260,7 @@ func (f *Fetcher) fetchChunk(index int) (err error) {
 		return err
 	}
 
-	var buf = make([]byte, 8192)
+	var buf = make([]byte, 64*1024) // 64KB
 
 	// 重试10次
 	for i := 0; i < 10; i++ {
diff --git a/tool/helper.go b/tool/helper.go
index 2b5935d..2015e6a 100644
--- a/tool/helper.go
+++ b/tool/helper.go
@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"github.com/spf13/cast"
 	"io"
 	"math"
 	"math/rand"
@@ -43,7 +44,7 @@ func ByteFmt(size int64) string {
 	if frac > 0 {
 		return fmt.Sprintf("%.1f%s", math.Floor(val*10)/10, unitArr[p])
 	} else {
-		return fmt.Sprintf("%d%s", int(val), unitArr[p])
+		return fmt.Sprintf("%d%s", cast.ToInt(val), unitArr[p])
 	}
 }