diff --git a/index.js b/index.js
index bd093fda..6c614b66 100644
--- a/index.js
+++ b/index.js
@@ -714,7 +714,7 @@ class Hypercore extends EventEmitter {
       once = false
       this._findingPeers--
       if (this.core !== null && --this.core.replicator.findingPeers === 0) {
-        this.core.replicator.updateAll()
+        this.core.replicator.queueUpdateAll()
       }
     }
   }
diff --git a/lib/replicator.js b/lib/replicator.js
index e6cb1ad8..eae8922c 100644
--- a/lib/replicator.js
+++ b/lib/replicator.js
@@ -48,8 +48,8 @@ const SCALE_LATENCY = 50
 const NOT_DOWNLOADING_SLACK = (20000 + Math.random() * 20000) | 0
 const MAX_PEERS_UPGRADE = 3
 const LAST_BLOCKS = 256
-
 const MAX_RANGES = 64
+const MIN_PEER_UPDATE_ALL = 40
 
 const NOT_AVAILABLE = 1
 const INVALID_REQUEST = 2
@@ -754,7 +754,7 @@ class Peer {
 
     if (this.remoteOpened === false) {
       this.replicator._ifAvailable--
-      this.replicator.updateAll()
+      this.replicator.queueUpdateAll()
       return
     }
 
@@ -1298,7 +1298,7 @@ class Peer {
     const req = request > 0 ? this.replicator._inflight.get(request) : null
 
     if (req === null || req.peer !== this) {
-      this.replicator.updateAll()
+      this.replicator.queueUpdateAll()
       return
     }
 
@@ -2021,6 +2021,9 @@ module.exports = class Replicator {
     this._notDownloadingLinger = notDownloadingLinger
     this._notDownloadingTimer = null
 
+    this._updateAllBump = null
+    this._updateAllBound = this.updateAll.bind(this)
+
     const self = this
     this._onstreamclose = onstreamclose
 
@@ -2203,7 +2206,7 @@ module.exports = class Replicator {
 
     const ref = this._addUpgrade().attach(session)
 
-    this.updateAll()
+    this.queueUpdateAll()
 
     return ref
   }
@@ -2213,7 +2216,7 @@ module.exports = class Replicator {
     const ref = b.attach(session)
 
     this._queueBlock(b)
-    this.updateAll()
+    this.queueUpdateAll()
 
     return ref
   }
@@ -2223,7 +2226,7 @@ module.exports = class Replicator {
     const ref = s.attach(session)
 
     this._seeks.push(s)
-    this.updateAll()
+    this.queueUpdateAll()
 
     return ref
   }
@@ -2266,7 +2269,7 @@ module.exports = class Replicator {
       return ref
     }
 
-    this.updateAll()
+    this.queueUpdateAll()
 
     return ref
   }
@@ -2288,7 +2291,7 @@ module.exports = class Replicator {
     }
 
     for (const replicator of updated) {
-      replicator.updateAll()
+      replicator.queueUpdateAll()
     }
   }
 
@@ -2300,7 +2303,7 @@ module.exports = class Replicator {
       cleared = true
     }
 
-    if (cleared) this.updateAll()
+    if (cleared) this.queueUpdateAll()
   }
 
   _matchingRequest(req, data) {
@@ -2460,7 +2463,7 @@ module.exports = class Replicator {
     }
 
     this._onpeerupdate(false, peer)
-    if (inflight) this.updateAll()
+    if (inflight) this.queueUpdateAll()
   }
 
   _queueBlock(b) {
@@ -2650,7 +2653,7 @@ module.exports = class Replicator {
       this._updatesPending = 0
     }
 
-    if (this._inflight.idle || updateAll) this.updateAll()
+    if (this._inflight.idle || updateAll) this.queueUpdateAll()
   }
 
   _maybeResolveIfAvailableRanges() {
@@ -2716,7 +2719,7 @@ module.exports = class Replicator {
       this._clearRequest(peer, req)
     }
 
-    this.updateAll()
+    this.queueUpdateAll()
   }
 
   _openSkipBitfield() {
@@ -2839,7 +2842,7 @@ module.exports = class Replicator {
     const f = this._addReorg(data.fork, peer)
 
     if (f === null) {
-      this.updateAll()
+      this.queueUpdateAll()
       return
     }
 
@@ -2860,7 +2863,7 @@ module.exports = class Replicator {
       }
     }
 
-    this.updateAll()
+    this.queueUpdateAll()
   }
 
   // Never throws, allowed to run in the background
@@ -2900,7 +2903,7 @@ module.exports = class Replicator {
     for (const f of old) f.resolve()
     f.resolve()
 
-    this.updateAll()
+    this.queueUpdateAll()
   }
 
   _maybeUpdate() {
@@ -3023,16 +3026,25 @@ module.exports = class Replicator {
     this._maybeResolveIfAvailableRanges()
   }
 
-  updateAll() {
+  updateAll(limit = Infinity) {
     // Quick shortcut to wait for flushing reorgs - not needed but less waisted requests
     if (this._applyingReorg !== null) return
 
+    // Clear queued scan if a full scan
+    if (this._updateAllBump !== null && limit === Infinity) {
+      clearTimeout(this._updateAllBump)
+      this._updateAllBump = null
+    }
+
     const peers = new RandomIterator(this.peers)
 
+    let tried = 0
     for (const peer of peers) {
+      tried++
       if (this._updatePeer(peer) === true) {
         peers.requeue()
       }
+      if (tried >= limit) break
     }
 
     // Check if we can skip the non primary check fully
@@ -3041,16 +3053,34 @@ module.exports = class Replicator {
       return
     }
 
+    tried = 0
     for (const peer of peers.restart()) {
+      tried++
       if (this._updatePeerNonPrimary(peer) === true) {
         peers.requeue()
       }
+      if (tried >= limit) break
     }
 
     this._checkUpgradeIfAvailable()
     this._maybeResolveIfAvailableRanges()
   }
 
+  getUpdateAllDelay(peers) {
+    return Math.min(3000, Math.max(100, (peers.length - MIN_PEER_UPDATE_ALL) * 5))
+  }
+
+  queueUpdateAll() {
+    if (this.peers.length < MIN_PEER_UPDATE_ALL) return this.updateAll()
+
+    // Immediately scan subset
+    this.updateAll(MIN_PEER_UPDATE_ALL)
+
+    // Schedule full scan
+    if (this._updateAllBump !== null) return //skip if already scheduled
+    this._updateAllBump = setTimeout(this._updateAllBound, this.getUpdateAllDelay(this.peers))
+  }
+
   onpeerdestroy() {
     if (--this._active === 0) this.core.checkIfIdle()
   }