diff --git a/proto/backend.proto b/proto/backend.proto
index f48a7453e..32ac11817 100644
--- a/proto/backend.proto
+++ b/proto/backend.proto
@@ -92,6 +92,7 @@ message BackendInput {
         Empty deck_tree_legacy = 77;
         FieldNamesForNotesIn field_names_for_notes = 78;
         FindAndReplaceIn find_and_replace = 79;
+        AfterNoteUpdatesIn after_note_updates = 80;
     }
 }
 
@@ -163,6 +164,7 @@ message BackendOutput {
         bytes deck_tree_legacy = 77;
         FieldNamesForNotesOut field_names_for_notes = 78;
         uint32 find_and_replace = 79;
+        Empty after_note_updates = 80;
 
         BackendError error = 2047;
     }
@@ -732,3 +734,9 @@ message FindAndReplaceIn {
     bool match_case = 5;
     string field_name = 6;
 }
+
+message AfterNoteUpdatesIn {
+    repeated int64 nids = 1;
+    bool mark_notes_modified = 2;
+    bool generate_cards = 3;
+}
diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index b6c73234a..3ad11cd83 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -14,7 +14,7 @@ import time
 import traceback
 import unicodedata
 import weakref
-from typing import Any, Dict, Iterable, List, Optional, Sequence, Tuple, Union
+from typing import Any, Iterable, List, Optional, Sequence, Tuple, Union
 
 import anki.find
 import anki.latex  # sets up hook
@@ -34,16 +34,7 @@ from anki.rsbackend import TR, RustBackend
 from anki.sched import Scheduler as V1Scheduler
 from anki.schedv2 import Scheduler as V2Scheduler
 from anki.tags import TagManager
-from anki.utils import (
-    devMode,
-    fieldChecksum,
-    ids2str,
-    intTime,
-    joinFields,
-    maxID,
-    splitFields,
-    stripHTMLMedia,
-)
+from anki.utils import devMode, ids2str, intTime, joinFields
 
 
 # this is initialized by storage.Collection
@@ -359,81 +350,6 @@ crt=?, mod=?, scm=?, dty=?, usn=?, ls=?""",
                 ok.append(t)
         return ok
 
-    def genCards(self, nids: List[int]) -> List[int]:
-        "Generate cards for non-empty templates, return ids to remove."
-        # build map of (nid,ord) so we don't create dupes
-        snids = ids2str(nids)
-        have: Dict[int, Dict[int, int]] = {}
-        dids: Dict[int, Optional[int]] = {}
-        dues: Dict[int, int] = {}
-        for id, nid, ord, did, due, odue, odid, type in self.db.execute(
-            "select id, nid, ord, did, due, odue, odid, type from cards where nid in "
-            + snids
-        ):
-            # existing cards
-            if nid not in have:
-                have[nid] = {}
-            have[nid][ord] = id
-            # if in a filtered deck, add new cards to original deck
-            if odid != 0:
-                did = odid
-            # and their dids
-            if nid in dids:
-                if dids[nid] and dids[nid] != did:
-                    # cards are in two or more different decks; revert to
-                    # model default
-                    dids[nid] = None
-            else:
-                # first card or multiple cards in same deck
-                dids[nid] = did
-            # save due
-            if odid != 0:
-                due = odue
-            if nid not in dues and type == 0:
-                # Add due to new card only if it's the due of a new sibling
-                dues[nid] = due
-        # build cards for each note
-        data = []
-        ts = maxID(self.db)
-        now = intTime()
-        rem = []
-        usn = self.usn()
-        for nid, mid, flds in self.db.execute(
-            "select id, mid, flds from notes where id in " + snids
-        ):
-            model = self.models.get(mid)
-            assert model
-            avail = self.models.availOrds(model, flds)
-            did = dids.get(nid) or model["did"]
-            due = dues.get(nid)
-            # add any missing cards
-            for t in self._tmplsFromOrds(model, avail):
-                doHave = nid in have and t["ord"] in have[nid]
-                if not doHave:
-                    # check deck is not a cram deck
-                    did = t["did"] or did
-                    if self.decks.isDyn(did):
-                        did = 1
-                    # if the deck doesn't exist, use default instead
-                    did = self.decks.get(did)["id"]
-                    # use sibling due# if there is one, else use a new id
-                    if due is None:
-                        due = self.nextID("pos")
-                    data.append((ts, nid, did, t["ord"], now, usn, due))
-                    ts += 1
-            # note any cards that need removing
-            if nid in have:
-                for ord, id in list(have[nid].items()):
-                    if ord not in avail:
-                        rem.append(id)
-        # bulk update
-        self.db.executemany(
-            """
-insert into cards values (?,?,?,?,?,?,0,0,?,0,0,0,0,0,0,0,0,"")""",
-            data,
-        )
-        return rem
-
     # type is no longer used
     def previewCards(
         self, note: Note, type: int = 0, did: Optional[int] = None
@@ -535,31 +451,24 @@ select id from notes where id in %s and id not in (select nid from cards)"""
         print("emptyCids() will go away")
         return []
 
-    # Field checksums and sorting fields
+    # Card generation & field checksums/sort fields
     ##########################################################################
 
-    def _fieldData(self, snids: str) -> Any:
-        return self.db.execute("select id, mid, flds from notes where id in " + snids)
+    def after_note_updates(self, nids: List[int], mark_modified: bool, generate_cards: bool = True) -> None:
+        self.backend.after_note_updates(
+            nids=nids, generate_cards=generate_cards, mark_notes_modified=mark_modified
+        )
+
+    # legacy
 
     def updateFieldCache(self, nids: List[int]) -> None:
-        "Update field checksums and sort cache, after find&replace, etc."
-        snids = ids2str(nids)
-        r = []
-        for (nid, mid, flds) in self._fieldData(snids):
-            fields = splitFields(flds)
-            model = self.models.get(mid)
-            if not model:
-                # note points to invalid model
-                continue
-            r.append(
-                (
-                    stripHTMLMedia(fields[self.models.sortIdx(model)]),
-                    fieldChecksum(fields[0]),
-                    nid,
-                )
-            )
-        # apply, relying on calling code to bump usn+mod
-        self.db.executemany("update notes set sfld=?, csum=? where id=?", r)
+        self.after_note_updates(nids, mark_modified=False, generate_cards=False)
+
+    # this also updates field cache
+    def genCards(self, nids: List[int]) -> List[int]:
+        self.after_note_updates(nids, mark_modified=False, generate_cards=True)
+        # previously returned empty cards, no longer does
+        return []
 
     # Finding cards
     ##########################################################################
@@ -909,7 +818,7 @@ select id from cards where odid > 0 and did in %s"""
         self.tags.registerNotes()
         # field cache
         for m in self.models.all():
-            self.updateFieldCache(self.models.nids(m))
+            self.after_note_updates(self.models.nids(m), mark_modified=False, generate_cards=False)
         # new cards can't have a due position > 32 bits, so wrap items over
         # 2 million back to 1 million
         self.db.execute(
diff --git a/pylib/anki/importing/noteimp.py b/pylib/anki/importing/noteimp.py
index 69d6a306a..13aabeddc 100644
--- a/pylib/anki/importing/noteimp.py
+++ b/pylib/anki/importing/noteimp.py
@@ -197,11 +197,8 @@ class NoteImporter(Importer):
                     firsts[fld0] = True
         self.addNew(new)
         self.addUpdates(updates)
-        # make sure to update sflds, etc
-        self.col.updateFieldCache(self._ids)
-        # generate cards
-        if self.col.genCards(self._ids):
-            self.log.insert(0, _("Empty cards found. Please run Tools>Empty Cards."))
+        # generate cards + update field cache
+        self.col.after_note_updates(self._ids, mark_modified=False)
         # apply scheduling updates
         self.updateCards()
         # we randomize or order here, to ensure that siblings
diff --git a/pylib/anki/models.py b/pylib/anki/models.py
index 6d05552c1..f0500b717 100644
--- a/pylib/anki/models.py
+++ b/pylib/anki/models.py
@@ -448,7 +448,7 @@ class ModelManager:
             self._changeNotes(nids, newModel, fmap)
         if cmap:
             self._changeCards(nids, m, newModel, cmap)
-        self.col.genCards(nids)
+        self.col.after_note_updates(nids, mark_modified=True)
 
     def _changeNotes(
         self, nids: List[int], newModel: NoteType, map: Dict[int, Union[None, int]]
@@ -470,7 +470,6 @@ class ModelManager:
         self.col.db.executemany(
             "update notes set flds=?,mid=?,mod=?,usn=? where id = ?", d
         )
-        self.col.updateFieldCache(nids)
 
     def _changeCards(
         self,
@@ -518,7 +517,7 @@ class ModelManager:
     # Required field/text cache
     ##########################################################################
 
-    # fixme: genCards(), clayout, importing, cards.isEmpty
+    # fixme: clayout, importing, cards.isEmpty
     def availOrds(self, m: NoteType, flds: str) -> List:
         "Given a joined field string, return available template ordinals."
         if m["type"] == MODEL_CLOZE:
diff --git a/pylib/anki/rsbackend.py b/pylib/anki/rsbackend.py
index ef964e8e7..cf33fda42 100644
--- a/pylib/anki/rsbackend.py
+++ b/pylib/anki/rsbackend.py
@@ -778,6 +778,20 @@ class RustBackend:
             release_gil=True,
         ).find_and_replace
 
+    def after_note_updates(
+        self, nids: List[int], generate_cards: bool, mark_notes_modified: bool
+    ) -> None:
+        self._run_command(
+            pb.BackendInput(
+                after_note_updates=pb.AfterNoteUpdatesIn(
+                    nids=nids,
+                    generate_cards=generate_cards,
+                    mark_notes_modified=mark_notes_modified,
+                )
+            ),
+            release_gil=True
+        )
+
 
 def translate_string_in(
     key: TR, **kwargs: Union[str, int, float]
diff --git a/rslib/src/backend/mod.rs b/rslib/src/backend/mod.rs
index 3daed136d..f3c085c9f 100644
--- a/rslib/src/backend/mod.rs
+++ b/rslib/src/backend/mod.rs
@@ -366,6 +366,9 @@ impl Backend {
                 OValue::FieldNamesForNotes(self.field_names_for_notes(input)?)
             }
             Value::FindAndReplace(input) => OValue::FindAndReplace(self.find_and_replace(input)?),
+            Value::AfterNoteUpdates(input) => {
+                OValue::AfterNoteUpdates(self.after_note_updates(input)?)
+            }
         })
     }
 
@@ -1094,6 +1097,21 @@ impl Backend {
             col.find_and_replace(FindReplaceContext::new(nids, &search, &repl, field_name)?)
         })
     }
+
+    fn after_note_updates(&self, input: pb::AfterNoteUpdatesIn) -> Result<pb::Empty> {
+        self.with_col(|col| {
+            col.transact(None, |col| {
+                let nids: Vec<_> = input.nids.into_iter().map(NoteID).collect();
+                col.after_note_updates(
+                    &nids,
+                    col.usn()?,
+                    input.generate_cards,
+                    input.mark_notes_modified,
+                )?;
+                Ok(pb::Empty {})
+            })
+        })
+    }
 }
 
 fn translate_arg_to_fluent_val(arg: &pb::TranslateArgValue) -> FluentValue {
diff --git a/rslib/src/findreplace.rs b/rslib/src/findreplace.rs
index cfa9cf50f..9e2e0126a 100644
--- a/rslib/src/findreplace.rs
+++ b/rslib/src/findreplace.rs
@@ -77,7 +77,7 @@ impl Collection {
                     }
                 }
                 if changed {
-                    self.update_note_inner(&genctx, &mut note)?;
+                    self.update_note_inner_generating_cards(&genctx, &mut note, true)?;
                     total_changed += 1;
                 }
             }
diff --git a/rslib/src/media/check.rs b/rslib/src/media/check.rs
index 5f33471b3..d412cd36c 100644
--- a/rslib/src/media/check.rs
+++ b/rslib/src/media/check.rs
@@ -404,7 +404,8 @@ where
                 &self.mgr.media_folder,
             )? {
                 // note was modified, needs saving
-                note.prepare_for_update(nt, Some(usn))?;
+                note.prepare_for_update(nt)?;
+                note.set_modified(usn);
                 self.ctx.storage.update_note(&note)?;
                 collection_modified = true;
             }
diff --git a/rslib/src/notes.rs b/rslib/src/notes.rs
index f80592a46..d8fcf2f68 100644
--- a/rslib/src/notes.rs
+++ b/rslib/src/notes.rs
@@ -12,6 +12,7 @@ use crate::{
     timestamp::TimestampSecs,
     types::Usn,
 };
+use itertools::Itertools;
 use num_integer::Integer;
 use std::{collections::HashSet, convert::TryInto};
 
@@ -63,8 +64,8 @@ impl Note {
         Ok(())
     }
 
-    /// Prepare note for saving to the database. If usn is provided, mtime will be bumped.
-    pub fn prepare_for_update(&mut self, nt: &NoteType, usn: Option<Usn>) -> Result<()> {
+    /// Prepare note for saving to the database. Does not mark it as modified.
+    pub fn prepare_for_update(&mut self, nt: &NoteType) -> Result<()> {
         assert!(nt.id == self.ntid);
         if nt.fields.len() != self.fields.len() {
             return Err(AnkiError::invalid_input(format!(
@@ -88,13 +89,14 @@ impl Note {
         };
         self.sort_field = Some(sort_field.into());
         self.checksum = Some(checksum);
-        if let Some(usn) = usn {
-            self.mtime = TimestampSecs::now();
-            self.usn = usn;
-        }
         Ok(())
     }
 
+    pub(crate) fn set_modified(&mut self, usn: Usn) {
+        self.mtime = TimestampSecs::now();
+        self.usn = usn;
+    }
+
     pub(crate) fn nonempty_fields<'a>(&self, fields: &'a [NoteField]) -> HashSet<&'a str> {
         self.fields
             .iter()
@@ -193,7 +195,8 @@ impl Collection {
         did: DeckID,
     ) -> Result<()> {
         self.canonify_note_tags(note, ctx.usn)?;
-        note.prepare_for_update(&ctx.notetype, Some(ctx.usn))?;
+        note.prepare_for_update(&ctx.notetype)?;
+        note.set_modified(ctx.usn);
         self.storage.add_note(note)?;
         self.generate_cards_for_new_note(ctx, note, did)
     }
@@ -204,21 +207,33 @@ impl Collection {
                 .get_notetype(note.ntid)?
                 .ok_or_else(|| AnkiError::invalid_input("missing note type"))?;
             let ctx = CardGenContext::new(&nt, col.usn()?);
-            col.update_note_inner(&ctx, note)
+            col.update_note_inner_generating_cards(&ctx, note, true)
         })
     }
 
-    pub(crate) fn update_note_inner(
+    pub(crate) fn update_note_inner_generating_cards(
         &mut self,
         ctx: &CardGenContext,
         note: &mut Note,
+        mark_note_modified: bool,
     ) -> Result<()> {
-        self.canonify_note_tags(note, ctx.usn)?;
-        note.prepare_for_update(ctx.notetype, Some(ctx.usn))?;
-        self.generate_cards_for_existing_note(ctx, note)?;
-        self.storage.update_note(note)?;
+        self.update_note_inner_without_cards(note, ctx.notetype, ctx.usn, mark_note_modified)?;
+        self.generate_cards_for_existing_note(ctx, note)
+    }
 
-        Ok(())
+    pub(crate) fn update_note_inner_without_cards(
+        &mut self,
+        note: &mut Note,
+        nt: &NoteType,
+        usn: Usn,
+        mark_note_modified: bool,
+    ) -> Result<()> {
+        self.canonify_note_tags(note, usn)?;
+        note.prepare_for_update(nt)?;
+        if mark_note_modified {
+            note.set_modified(usn);
+        }
+        self.storage.update_note(note)
     }
 
     /// Remove a note. Cards must already have been deleted.
@@ -230,6 +245,42 @@ impl Collection {
         }
         Ok(())
     }
+
+    /// Update cards and field cache after notes modified externally.
+    /// If gencards is false, skip card generation.
+    pub(crate) fn after_note_updates(
+        &mut self,
+        nids: &[NoteID],
+        usn: Usn,
+        generate_cards: bool,
+        mark_notes_modified: bool,
+    ) -> Result<()> {
+        let nids_by_notetype = self.storage.note_ids_by_notetype(nids)?;
+        for (ntid, group) in &nids_by_notetype.into_iter().group_by(|tup| tup.0) {
+            let nt = self
+                .get_notetype(ntid)?
+                .ok_or_else(|| AnkiError::invalid_input("missing note type"))?;
+            let genctx = CardGenContext::new(&nt, usn);
+            for (_, nid) in group {
+                let mut note = self.storage.get_note(nid)?.unwrap();
+                if generate_cards {
+                    self.update_note_inner_generating_cards(
+                        &genctx,
+                        &mut note,
+                        mark_notes_modified,
+                    )?;
+                } else {
+                    self.update_note_inner_without_cards(
+                        &mut note,
+                        &genctx.notetype,
+                        usn,
+                        mark_notes_modified,
+                    )?;
+                }
+            }
+        }
+        Ok(())
+    }
 }
 
 #[cfg(test)]
diff --git a/rslib/src/notetype/schemachange.rs b/rslib/src/notetype/schemachange.rs
index f073a2566..de8db24b8 100644
--- a/rslib/src/notetype/schemachange.rs
+++ b/rslib/src/notetype/schemachange.rs
@@ -63,7 +63,7 @@ impl Collection {
                 let nids = self.search_notes_only(&format!("mid:{}", nt.id))?;
                 for nid in nids {
                     let mut note = self.storage.get_note(nid)?.unwrap();
-                    note.prepare_for_update(nt, None)?;
+                    note.prepare_for_update(nt)?;
                     self.storage.update_note(&note)?;
                 }
             } else {
@@ -92,7 +92,8 @@ impl Collection {
                 })
                 .map(Into::into)
                 .collect();
-            note.prepare_for_update(nt, Some(usn))?;
+            note.prepare_for_update(nt)?;
+            note.set_modified(usn);
             self.storage.update_note(&note)?;
         }
         Ok(())