diff --git a/speedtest/data_manager.go b/speedtest/data_manager.go
index 5d80720..04546ac 100644
--- a/speedtest/data_manager.go
+++ b/speedtest/data_manager.go
@@ -55,7 +55,7 @@ type Chunk interface {
 	Read(b []byte) (n int, err error)
 }
 
-const readChunkSize = 1024 * 32 // 32 KBytes
+const readChunkSize = 1024 // 1 KBytes with higher frequency rate feedback
 
 type DataType int32
 
@@ -448,23 +448,38 @@ func (dc *DataChunk) GetParent() Manager {
 	return dc.manager
 }
 
-func (dc *DataChunk) Read(b []byte) (n int, err error) {
-	if !dc.manager.running {
-		return n, io.EOF
-	}
-	if dc.remainOrDiscardSize < readChunkSize {
-		if dc.remainOrDiscardSize <= 0 {
+// WriteTo Used to hook all traffic.
+func (dc *DataChunk) WriteTo(w io.Writer) (written int64, err error) {
+	nw := 0
+	nr := readChunkSize
+	for {
+		if !dc.manager.running || dc.remainOrDiscardSize <= 0 {
 			dc.endTime = time.Now()
-			return n, io.EOF
+			return written, io.EOF
+		}
+		if dc.remainOrDiscardSize < readChunkSize {
+			nr = int(dc.remainOrDiscardSize)
+			nw, err = w.Write((*dc.manager.repeatByte)[:nr])
+		} else {
+			nw, err = w.Write(*dc.manager.repeatByte)
+		}
+		if err != nil {
+			return
+		}
+		n64 := int64(nw)
+		written += n64
+		dc.remainOrDiscardSize -= n64
+		dc.manager.AddTotalUpload(n64)
+		if nr != nw {
+			return written, io.ErrShortWrite
 		}
-		n = copy(b, (*dc.manager.repeatByte)[:dc.remainOrDiscardSize])
-	} else {
-		n = copy(b, *dc.manager.repeatByte)
 	}
-	n64 := int64(n)
-	dc.remainOrDiscardSize -= n64
-	atomic.AddInt64(&dc.manager.upload.totalDataVolume, n64)
-	return
+}
+
+// Please don't call it, only used to wrapped by [io.NopCloser]
+// We use [DataChunk.WriteTo] that implements [io.WriterTo] to bypass this function.
+func (dc *DataChunk) Read(b []byte) (n int, err error) {
+	panic("unexpected call: only used to implement the io.Reader")
 }
 
 // calcMAFilter Median-Averaging Filter
diff --git a/speedtest/request.go b/speedtest/request.go
index 54acd6b..f188d56 100644
--- a/speedtest/request.go
+++ b/speedtest/request.go
@@ -186,13 +186,11 @@ func downloadRequest(ctx context.Context, s *Server, w int) error {
 func uploadRequest(ctx context.Context, s *Server, w int) error {
 	size := ulSizes[w]
 	dc := s.Context.NewChunk().UploadHandler(int64(size*100-51) * 10)
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, s.URL, dc)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, s.URL, io.NopCloser(dc))
 	if err != nil {
 		return err
 	}
-	req.ContentLength = dc.(*DataChunk).ContentLength
 	dbg.Printf("Len=%d, XulURL: %s\n", req.ContentLength, s.URL)
-
 	req.Header.Set("Content-Type", "application/octet-stream")
 	resp, err := s.Context.doer.Do(req)
 	if err != nil {