diff --git a/syncapi/streams/stream_pdu.go b/syncapi/streams/stream_pdu.go
index 220629cfb..ae38dc30e 100644
--- a/syncapi/streams/stream_pdu.go
+++ b/syncapi/streams/stream_pdu.go
@@ -11,9 +11,15 @@ import (
 	"go.uber.org/atomic"
 )
 
-const PDU_STREAM_QUEUESIZE = 2048
+// The max number of per-room goroutines to have running.
+// Too high and this will consume lots of CPU, too low and complete
+// sync responses will take longer to process.
 const PDU_STREAM_WORKERS = 256
 
+// The maximum number of tasks that can be queued in total before
+// backpressure will build up and the rests will start to block.
+const PDU_STREAM_QUEUESIZE = PDU_STREAM_WORKERS * 8
+
 type PDUStreamProvider struct {
 	StreamProvider