diff --git a/CHANGELOG-3.5.md b/CHANGELOG-3.5.md
index 1a875e8f687..4784126780c 100644
--- a/CHANGELOG-3.5.md
+++ b/CHANGELOG-3.5.md
@@ -156,7 +156,8 @@ Note that any `etcd_debugging_*` metrics are experimental and subject to change.
 - Add [`--socket-reuse-port`](https://github.com/etcd-io/etcd/pull/12702) flag
   - Setting this flag enables `SO_REUSEPORT` which allows rebind of a port already in use. User should take caution when using this flag to ensure flock is properly enforced. 
 - Add [`--socket-reuse-address`](https://github.com/etcd-io/etcd/pull/12702) flag
-  - Setting this flag enables `SO_REUSEADDR` which allows binding to an address in `TIME_WAIT` state, improving etcd restart time. 
+  - Setting this flag enables `SO_REUSEADDR` which allows binding to an address in `TIME_WAIT` state, improving etcd restart time.
+- Reduce [around 30% memory allocation by logging range response size without marshal](https://github.com/etcd-io/etcd/pull/12871).
 ### Package `runtime`
 
 - Optimize [`runtime.FDUsage` by removing unnecessary sorting](https://github.com/etcd-io/etcd/pull/12214).
diff --git a/server/etcdserver/apply.go b/server/etcdserver/apply.go
index f80f89ca332..b249555ae92 100644
--- a/server/etcdserver/apply.go
+++ b/server/etcdserver/apply.go
@@ -245,7 +245,7 @@ func (a *applierV3backend) Put(ctx context.Context, txn mvcc.TxnWrite, p *pb.Put
 		trace = traceutil.New("put",
 			a.s.Logger(),
 			traceutil.Field{Key: "key", Value: string(p.Key)},
-			traceutil.Field{Key: "req_size", Value: proto.Size(p)},
+			traceutil.Field{Key: "req_size", Value: p.Size()},
 		)
 	}
 	val, leaseID := p.Value, lease.LeaseID(p.Lease)
@@ -625,7 +625,7 @@ func (a *applierV3backend) applyTxn(ctx context.Context, txn mvcc.TxnWrite, rt *
 			trace.StartSubTrace(
 				traceutil.Field{Key: "req_type", Value: "put"},
 				traceutil.Field{Key: "key", Value: string(tv.RequestPut.Key)},
-				traceutil.Field{Key: "req_size", Value: proto.Size(tv.RequestPut)})
+				traceutil.Field{Key: "req_size", Value: tv.RequestPut.Size()})
 			resp, _, err := a.Put(ctx, txn, tv.RequestPut)
 			if err != nil {
 				lg.Panic("unexpected error during txn", zap.Error(err))
diff --git a/server/etcdserver/util.go b/server/etcdserver/util.go
index 87cf8ed9a84..265dbae6737 100644
--- a/server/etcdserver/util.go
+++ b/server/etcdserver/util.go
@@ -139,7 +139,7 @@ func warnOfExpensiveReadOnlyTxnRequest(lg *zap.Logger, warningApplyDuration time
 				// only range responses should be in a read only txn request
 			}
 		}
-		resp = fmt.Sprintf("responses:<%s> size:%d", strings.Join(resps, " "), proto.Size(txnResponse))
+		resp = fmt.Sprintf("responses:<%s> size:%d", strings.Join(resps, " "), txnResponse.Size())
 	}
 	warnOfExpensiveGenericRequest(lg, warningApplyDuration, now, reqStringer, "read-only txn ", resp, err)
 }
@@ -147,7 +147,7 @@ func warnOfExpensiveReadOnlyTxnRequest(lg *zap.Logger, warningApplyDuration time
 func warnOfExpensiveReadOnlyRangeRequest(lg *zap.Logger, warningApplyDuration time.Duration, now time.Time, reqStringer fmt.Stringer, rangeResponse *pb.RangeResponse, err error) {
 	var resp string
 	if !isNil(rangeResponse) {
-		resp = fmt.Sprintf("range_response_count:%d size:%d", len(rangeResponse.Kvs), proto.Size(rangeResponse))
+		resp = fmt.Sprintf("range_response_count:%d size:%d", len(rangeResponse.Kvs), rangeResponse.Size())
 	}
 	warnOfExpensiveGenericRequest(lg, warningApplyDuration, now, reqStringer, "read-only range ", resp, err)
 }