diff --git a/src/core/config/mod.rs b/src/core/config/mod.rs
index ed1f5e75..a4222f19 100644
--- a/src/core/config/mod.rs
+++ b/src/core/config/mod.rs
@@ -2932,7 +2932,7 @@ fn default_pdu_cache_capacity() -> u32 { parallelism_scaled_u32(10_000).saturati
 fn default_cache_capacity_modifier() -> f64 { 1.0 }
 
 fn default_auth_chain_cache_capacity() -> u32 {
-	parallelism_scaled_u32(10_000).saturating_add(100_000)
+	parallelism_scaled_u32(100_000).saturating_add(50_000)
 }
 
 fn default_shorteventid_cache_capacity() -> u32 {
diff --git a/src/database/maps.rs b/src/database/maps.rs
index 1c64ddb5..b5d9cf5e 100644
--- a/src/database/maps.rs
+++ b/src/database/maps.rs
@@ -39,8 +39,8 @@ pub(super) static MAPS: &[Descriptor] = &[
 		cache_disp: CacheDisp::SharedWith("shorteventid_authchain"),
 		index_size: 512,
 		block_size: 4096,
-		key_size_hint: Some(8),
-		val_size_hint: Some(1024),
+		key_size_hint: Some(8), // intentionally match shorteventid_authchain
+		val_size_hint: Some(256),
 		..descriptor::RANDOM_CACHE
 	},
 	Descriptor {
@@ -290,7 +290,7 @@ pub(super) static MAPS: &[Descriptor] = &[
 		name: "shorteventid_authchain",
 		cache_disp: CacheDisp::SharedWith("authchainkey_authchain"),
 		key_size_hint: Some(8),
-		val_size_hint: Some(1024),
+		val_size_hint: Some(256),
 		index_size: 512,
 		block_size: 4096,
 		..descriptor::SEQUENTIAL