input-output-hk · SupernaviX · Aug 20, 2025 · Aug 20, 2025 · Aug 20, 2025 · Aug 20, 2025
diff --git a/data/simulation/config.d.ts b/data/simulation/config.d.ts
@@ -113,6 +113,8 @@ export interface Config {
   /** Only supported by Rust simulation. */
   "tx-validation-cpu-time-ms": number;
   /** Only supported by Rust simulation. */
+  "tx-validation-cpu-time-ms-per-byte": number;
+  /** Only supported by Rust simulation. */
   "tx-max-size-bytes": bigint;
   /**
    * What fraction of TXs (from 0 to 1) should introduce conflicts with transactions which were produced before?

diff --git a/data/simulation/config.default.yaml b/data/simulation/config.default.yaml
@@ -61,6 +61,7 @@ tx-overcollateralization-factor-distribution:
   distribution: constant
   value: 0
 tx-validation-cpu-time-ms: 1.5
+tx-validation-cpu-time-ms-per-byte: 0
 tx-max-size-bytes: 16384
 tx-conflict-fraction: 0
 

diff --git a/data/simulation/config.schema.json b/data/simulation/config.schema.json
@@ -511,6 +511,10 @@
       "description": "Only supported by Rust simulation.",
       "type": "number"
     },
+    "tx-validation-cpu-time-ms-per-byte": {
+      "description": "Only supported by Rust simulation.",
+      "type": "number"
+    },
     "vote-bundle-size-bytes-constant": {
       "additionalProperties": false,
       "properties": {},

diff --git a/sim-rs/CHANGELOG.md b/sim-rs/CHANGELOG.md
@@ -1,5 +1,19 @@
 # Changelog
 
+## v1.2.0
+
+### All Leios variants
+
+Add a `tx-validation-cpu-time-ms-per-byte` setting, a CPU cost which applies to transactions before adding them to the mempool (or to an EB in Linear Leios).
+
+### Linear Leios
+
+Respect cerificate CPU time settings:
+ - `cert-generation-cpu-time-ms-constant`
+ - `cert-generation-cpu-time-ms-per-node` (currently set to 0)
+ - `cert-validation-cpu-time-ms-constant`
+ - `cert-validation-cpu-time-ms-per-node` (currently set to 0)
+
 ## v1.1.0
 
 ### Linear Leios

diff --git a/sim-rs/Cargo.lock b/sim-rs/Cargo.lock
diff --git a/sim-rs/implementations/CLASSIC_LEIOS.md b/sim-rs/implementations/CLASSIC_LEIOS.md
@@ -76,7 +76,7 @@ If more than one EB matches all of these criteria, we use for tiebreakers
 ## CPU model
 |Task name in logs|Task name in code|When does it run|What happens when it completes|CPU cost
 |---|---|---|---|---|
-|`ValTX`|`TransactionValidated`|After a transaction has been received from a peer.|That TX is announced to other peers.|`tx-validation-cpu-time-ms`|
+|`ValTX`|`TransactionValidated`|After a transaction has been received from a peer.|That TX is announced to other peers.|`tx-validation-cpu-time-ms` + `tx-validation-cpu-time-ms-per-byte` for each byte of TX|
 |`GenRB`|`RBBlockGenerated`|After a new ranking block has been generated.|That RB is announced to peers.|`rb-generation-cpu-time-ms` + `cert-generation-cpu-time-ms-constant` + `cert-generation-cpu-time-ms-per-node` for each node that voted for the endorsed EB|
 |`ValRB`|`RBBlockValidated`|After a ranking block has been received.|That RB body is announced to peers and (potentially) accepted as the tip of the chain.|`rb-body-legacy-praos-payload-validation-cpu-time-ms-constant` + `rb-body-legacy-praos-payload-validation-cpu-time-ms-per-byte` for each byte of TX  + `cert-generation-cpu-time-ms-constant` + `cert-generation-cpu-time-ms-per-node` for each node that voted for the endorsed EB|
 |`GenIB`|`IBBlockGenerated`|After a new IB has been generated.|That IB is announced to peers.|`ib-generation-cpu-time-ms`|

diff --git a/sim-rs/implementations/LINEAR_LEIOS.md b/sim-rs/implementations/LINEAR_LEIOS.md
@@ -65,10 +65,10 @@ When a node receives an RB body, it immediately removes all referenced/conflicti
 ## CPU model
 |Task name in logs|Task name in code|When does it run|What happens when it completes|CPU cost
 |---|---|---|---|---|
-|`ValTX`|`TransactionValidated`|After a transaction has been received from a peer.|That TX is announced to other peers.|`tx-validation-cpu-time-ms`|
-|`GenRB`|`RBBlockGenerated`|After a new ranking block has been generated.|That RB and its EB are announced to peers.|RB generation and EB generation run in parallel.</br>**RB generation**: `rb-generation-cpu-time-ms` + the CPU time of `ValRB`<br/>**EB generation**: `eb-generation-cpu-time-ms` + the CPU time of `ValEB`|
+|`ValTX`|`TransactionValidated`|After a transaction has been received from a peer.|That TX is announced to other peers.|`tx-validation-cpu-time-ms` + `tx-validation-cpu-time-ms-per-byte` for each byte of TX|
+|`GenRB`|`RBBlockGenerated`|After a new ranking block has been generated.|That RB and its EB are announced to peers.|RB generation and EB generation run in parallel.</br>**RB generation**: `rb-generation-cpu-time-ms` + `cert-generation-cpu-time-ms-constant` + `cert-generation-cpu-time-ms-per-node` for each node that voted for the endorsed EB + `rb-body-legacy-praos-payload-validation-cpu-time-ms-constant` + `rb-body-legacy-praos-payload-validation-cpu-time-ms-per-byte` for each byte of TX<br/>**EB generation**: `eb-generation-cpu-time-ms` + the CPU time of `ValEB`|
 |`ValRH`|`RBHeaderValidated`|After a ranking block header has been received.|That RB is announced to peers.<br/>The referenced EB is queued to be downloaded when available.|`rb-head-validation-cpu-time-ms`|
-|`ValRB`|`RBBlockValidated`|After a ranking block body has been received.|That RB body is announced to peers and (potentially) accepted as the tip of the chain.|`rb-body-legacy-praos-payload-validation-cpu-time-ms-constant` + `rb-body-legacy-praos-payload-validation-cpu-time-ms-per-byte` for each byte of TX|
+|`ValRB`|`RBBlockValidated`|After a ranking block body has been received.|That RB body is announced to peers and (potentially) accepted as the tip of the chain.|`rb-body-legacy-praos-payload-validation-cpu-time-ms-constant` + `rb-body-legacy-praos-payload-validation-cpu-time-ms-per-byte` for each byte of TX + `cert-validation-cpu-time-ms-constant` + `cert-validation-cpu-time-ms-per-node` for each node that voted for the endorsed EB|
 |`ValEH`|`EBHeaderValidated`|After an EB header has been received and validated.|That EB is announced to peers, and body validation begins in the background.|`eb-header-validation-cpu-time-ms`|
 |`ValEB`|`EBBlockValidated`|After an EB's body has been validated.|If eligible, the node will vote for that EB.|`eb-body-validation-cpu-time-ms-constant` + `eb-body-validation-cpu-time-ms-per-byte` for each byte of TX|
 |`GenVote`|`VTBundleGenerated`|After a vote bundle has been generated.|That vote bundle is announced to peers.|`vote-generation-cpu-time-ms-constant` + `vote-generation-cpu-time-ms-per-tx` for each TX in the EB|

diff --git a/sim-rs/implementations/STRACCIATELLA.md b/sim-rs/implementations/STRACCIATELLA.md
@@ -15,7 +15,7 @@ Voting for endorser blocks also behaves mostly the same as in the original Leios
 ## CPU model
 |Task name in logs|Task name in code|When does it run|What happens when it completes|CPU cost
 |---|---|---|---|---|
-|`ValTX`|`TransactionValidated`|After a transaction has been received from a peer.|That TX is announced to other peers.|`tx-validation-cpu-time-ms`|
+|`ValTX`|`TransactionValidated`|After a transaction has been received from a peer.|That TX is announced to other peers.|`tx-validation-cpu-time-ms` + `tx-validation-cpu-time-ms-per-byte` for each byte of TX|
 |`GenRB`|`RBBlockGenerated`|After a new ranking block has been generated.|That RB is announced to peers.|`rb-generation-cpu-time-ms` + `cert-generation-cpu-time-ms-constant` + `cert-generation-cpu-time-ms-per-node` for each node that voted for the endorsed EB|
 |`ValRB`|`RBBlockValidated`|After a ranking block has been received.|That RB body is announced to peers and (potentially) accepted as the tip of the chain.|`rb-body-legacy-praos-payload-validation-cpu-time-ms-constant` + `rb-body-legacy-praos-payload-validation-cpu-time-ms-per-byte` for each byte of TX  + `cert-generation-cpu-time-ms-constant` + `cert-generation-cpu-time-ms-per-node` for each node that voted for the endorsed EB|
 |`GenEB`|`EBBlockGenerated`|After a new EB has been generated.|That EB is announced to peers.|`eb-generation-cpu-time-ms`|

diff --git a/sim-rs/sim-cli/Cargo.toml b/sim-rs/sim-cli/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sim-cli"
-version = "1.1.0"
+version = "1.2.0"
 edition = "2024"
 default-run = "sim-cli"
 rust-version = "1.88"

diff --git a/sim-rs/sim-core/Cargo.toml b/sim-rs/sim-core/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sim-core"
-version = "1.1.0"
+version = "1.2.0"
 edition = "2024"
 rust-version = "1.88"
 

diff --git a/sim-rs/sim-core/src/config.rs b/sim-rs/sim-core/src/config.rs
@@ -85,6 +85,7 @@ pub struct RawParameters {
     pub tx_size_bytes_distribution: DistributionConfig,
     pub tx_overcollateralization_factor_distribution: DistributionConfig,
     pub tx_validation_cpu_time_ms: f64,
+    pub tx_validation_cpu_time_ms_per_byte: f64,
     pub tx_max_size_bytes: u64,
     pub tx_conflict_fraction: Option<f64>,
     pub tx_start_time: Option<f64>,
@@ -393,7 +394,8 @@ impl From<RawTopology> for Topology {
 
 #[derive(Debug, Clone)]
 pub(crate) struct CpuTimeConfig {
-    pub tx_validation: Duration,
+    pub tx_validation_constant: Duration,
+    pub tx_validation_per_byte: Duration,
     pub rb_generation: Duration,
     pub rb_head_validation: Duration,
     pub rb_body_validation_constant: Duration,
@@ -419,7 +421,8 @@ pub(crate) struct CpuTimeConfig {
 impl CpuTimeConfig {
     fn new(params: &RawParameters) -> Self {
         Self {
-            tx_validation: duration_ms(params.tx_validation_cpu_time_ms),
+            tx_validation_constant: duration_ms(params.tx_validation_cpu_time_ms),
+            tx_validation_per_byte: duration_ms(params.tx_validation_cpu_time_ms_per_byte),
             rb_generation: duration_ms(params.rb_generation_cpu_time_ms),
             rb_head_validation: duration_ms(params.rb_head_validation_cpu_time_ms),
             rb_body_validation_constant: duration_ms(

diff --git a/sim-rs/sim-core/src/sim/leios.rs b/sim-rs/sim-core/src/sim/leios.rs
@@ -174,7 +174,9 @@ impl SimCpuTask for Task {
 
     fn times(&self, config: &crate::config::CpuTimeConfig) -> Vec<Duration> {
         match self {
-            Self::TransactionValidated(_, _) => vec![config.tx_validation],
+            Self::TransactionValidated(_, tx) => vec![
+                config.tx_validation_constant + config.tx_validation_per_byte * tx.bytes as u32,
+            ],
             Self::RBBlockGenerated(block) => {
                 let mut time = config.rb_generation;
                 if let Some(endorsement) = &block.endorsement {

diff --git a/sim-rs/sim-core/src/sim/linear_leios.rs b/sim-rs/sim-core/src/sim/linear_leios.rs
@@ -163,11 +163,18 @@ impl SimCpuTask for CpuTask {
 
     fn times(&self, config: &CpuTimeConfig) -> Vec<Duration> {
         match self {
-            Self::TransactionValidated(_, _) => vec![config.tx_validation],
+            Self::TransactionValidated(_, tx) => vec![
+                config.tx_validation_constant + config.tx_validation_per_byte * tx.bytes as u32,
+            ],
             Self::RBBlockGenerated(rb, eb, _) => {
                 let mut rb_time = config.rb_generation + config.rb_body_validation_constant;
                 let rb_bytes: u64 = rb.transactions.iter().map(|tx| tx.bytes).sum();
                 rb_time += config.rb_validation_per_byte * (rb_bytes as u32);
+                if let Some(endorsement) = &rb.endorsement {
+                    let nodes = endorsement.votes.len();
+                    rb_time += config.cert_generation_constant
+                        + (config.cert_generation_per_node * nodes as u32);
+                }
 
                 let mut eb_time = config.eb_generation + config.eb_body_validation_constant;
                 let eb_bytes: u64 = eb.txs.iter().map(|tx| tx.bytes).sum();
@@ -180,6 +187,11 @@ impl SimCpuTask for CpuTask {
                 let mut time = config.rb_body_validation_constant;
                 let bytes: u64 = rb.transactions.iter().map(|tx| tx.bytes).sum();
                 time += config.rb_validation_per_byte * (bytes as u32);
+                if let Some(endorsement) = &rb.endorsement {
+                    let nodes = endorsement.votes.len();
+                    time += config.cert_validation_constant
+                        + (config.cert_validation_per_node * nodes as u32);
+                }
                 vec![time]
             }
             Self::EBHeaderValidated(_, _) => vec![config.eb_header_validation],

diff --git a/sim-rs/sim-core/src/sim/stracciatella.rs b/sim-rs/sim-core/src/sim/stracciatella.rs
@@ -132,7 +132,9 @@ impl SimCpuTask for CpuTask {
 
     fn times(&self, config: &crate::config::CpuTimeConfig) -> Vec<std::time::Duration> {
         match self {
-            Self::TransactionValidated(_, _) => vec![config.tx_validation],
+            Self::TransactionValidated(_, tx) => vec![
+                config.tx_validation_constant + config.tx_validation_per_byte * tx.bytes as u32,
+            ],
             Self::RBBlockGenerated(rb) => {
                 let mut time = config.rb_generation;
                 if let Some(endorsement) = &rb.endorsement {