diff --git a/src/flake8_bugbear/plugins/duplicate_exceptions.rs b/src/flake8_bugbear/plugins/duplicate_exceptions.rs
index a1bcef2872..7390929672 100644
--- a/src/flake8_bugbear/plugins/duplicate_exceptions.rs
+++ b/src/flake8_bugbear/plugins/duplicate_exceptions.rs
@@ -1,6 +1,5 @@
-use std::collections::BTreeSet;
-
 use itertools::Itertools;
+use rustc_hash::FxHashSet;
 use rustpython_ast::{
     Excepthandler, ExcepthandlerKind, Expr, ExprContext, ExprKind, Location, Stmt,
 };
@@ -27,9 +26,9 @@ fn duplicate_handler_exceptions<'a>(
     checker: &mut Checker,
     expr: &'a Expr,
     elts: &'a [Expr],
-) -> BTreeSet<Vec<&'a str>> {
-    let mut seen: BTreeSet<Vec<&str>> = BTreeSet::default();
-    let mut duplicates: BTreeSet<Vec<&str>> = BTreeSet::default();
+) -> FxHashSet<Vec<&'a str>> {
+    let mut seen: FxHashSet<Vec<&str>> = FxHashSet::default();
+    let mut duplicates: FxHashSet<Vec<&str>> = FxHashSet::default();
     let mut unique_elts: Vec<&Expr> = Vec::default();
     for type_ in elts {
         let call_path = helpers::collect_call_paths(type_);
@@ -76,8 +75,8 @@ fn duplicate_handler_exceptions<'a>(
 }
 
 pub fn duplicate_exceptions(checker: &mut Checker, stmt: &Stmt, handlers: &[Excepthandler]) {
-    let mut seen: BTreeSet<Vec<&str>> = BTreeSet::default();
-    let mut duplicates: BTreeSet<Vec<&str>> = BTreeSet::default();
+    let mut seen: FxHashSet<Vec<&str>> = FxHashSet::default();
+    let mut duplicates: FxHashSet<Vec<&str>> = FxHashSet::default();
     for handler in handlers {
         let ExcepthandlerKind::ExceptHandler { type_: Some(type_), .. } = &handler.node else {
             continue;
diff --git a/src/flake8_import_conventions/checks.rs b/src/flake8_import_conventions/checks.rs
index 08c3c76423..cf6d588279 100644
--- a/src/flake8_import_conventions/checks.rs
+++ b/src/flake8_import_conventions/checks.rs
@@ -1,5 +1,4 @@
-use std::collections::BTreeMap;
-
+use rustc_hash::FxHashMap;
 use rustpython_ast::Stmt;
 
 use crate::ast::types::Range;
@@ -10,7 +9,7 @@ pub fn check_conventional_import(
     import_from: &Stmt,
     name: &str,
     asname: Option<&str>,
-    conventions: &BTreeMap<String, String>,
+    conventions: &FxHashMap<String, String>,
 ) -> Option<Check> {
     let mut is_valid_import = true;
     if let Some(expected_alias) = conventions.get(name) {
diff --git a/src/flake8_import_conventions/mod.rs b/src/flake8_import_conventions/mod.rs
index aebe43c2a6..33768530e7 100644
--- a/src/flake8_import_conventions/mod.rs
+++ b/src/flake8_import_conventions/mod.rs
@@ -3,10 +3,11 @@ pub mod settings;
 
 #[cfg(test)]
 mod tests {
-    use std::collections::BTreeMap;
+
     use std::path::Path;
 
     use anyhow::Result;
+    use rustc_hash::FxHashMap;
 
     use crate::checks::CheckCode;
     use crate::linter::test_path;
@@ -33,7 +34,7 @@ mod tests {
                     flake8_import_conventions::settings::Settings::from_options(
                         flake8_import_conventions::settings::Options {
                             aliases: None,
-                            extend_aliases: Some(BTreeMap::from([
+                            extend_aliases: Some(FxHashMap::from_iter([
                                 ("dask.array".to_string(), "da".to_string()),
                                 ("dask.dataframe".to_string(), "dd".to_string()),
                             ])),
@@ -56,7 +57,7 @@ mod tests {
                 flake8_import_conventions:
                     flake8_import_conventions::settings::Settings::from_options(
                         flake8_import_conventions::settings::Options {
-                            aliases: Some(BTreeMap::from([
+                            aliases: Some(FxHashMap::from_iter([
                                 ("altair".to_string(), "alt".to_string()),
                                 ("matplotlib.pyplot".to_string(), "plt".to_string()),
                                 ("pandas".to_string(), "pd".to_string()),
@@ -83,7 +84,7 @@ mod tests {
                     flake8_import_conventions::settings::Settings::from_options(
                         flake8_import_conventions::settings::Options {
                             aliases: None,
-                            extend_aliases: Some(BTreeMap::from([(
+                            extend_aliases: Some(FxHashMap::from_iter([(
                                 "numpy".to_string(),
                                 "nmp".to_string(),
                             )])),
diff --git a/src/flake8_import_conventions/settings.rs b/src/flake8_import_conventions/settings.rs
index db1517c495..e2ec838ffd 100644
--- a/src/flake8_import_conventions/settings.rs
+++ b/src/flake8_import_conventions/settings.rs
@@ -1,8 +1,10 @@
 //! Settings for import conventions.
 
-use std::collections::BTreeMap;
+use std::hash::{Hash, Hasher};
 
+use itertools::Itertools;
 use ruff_macros::ConfigurationOptions;
+use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 
 const CONVENTIONAL_ALIASES: &[(&str, &str)] = &[
@@ -20,7 +22,7 @@ pub struct Options {
         doc = "The conventional aliases for imports. These aliases can be extended by the \
                `extend_aliases` option.",
         default = r#"{"altair": "alt", "matplotlib.pyplot": "plt", "numpy": "np", "pandas": "pd", "seaborn": "sns"}"#,
-        value_type = "BTreeMap<String, String>",
+        value_type = "FxHashMap<String, String>",
         example = r#"
             # Declare the default aliases.
             altair = "alt"
@@ -30,33 +32,41 @@ pub struct Options {
             seaborn = "sns"
         "#
     )]
-    pub aliases: Option<BTreeMap<String, String>>,
+    pub aliases: Option<FxHashMap<String, String>>,
     #[option(
         doc = "A mapping of modules to their conventional import aliases. These aliases will be \
                added to the `aliases` mapping.",
         default = r#"{}"#,
-        value_type = "BTreeMap<String, String>",
+        value_type = "FxHashMap<String, String>",
         example = r#"
             # Declare a custom alias for the `matplotlib` module.
             "dask.dataframe" = "dd"
         "#
     )]
-    pub extend_aliases: Option<BTreeMap<String, String>>,
+    pub extend_aliases: Option<FxHashMap<String, String>>,
 }
 
-#[derive(Debug, Hash)]
+#[derive(Debug)]
 pub struct Settings {
-    pub aliases: BTreeMap<String, String>,
+    pub aliases: FxHashMap<String, String>,
 }
 
-fn default_aliases() -> BTreeMap<String, String> {
+impl Hash for Settings {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        for value in self.aliases.iter().sorted() {
+            value.hash(state);
+        }
+    }
+}
+
+fn default_aliases() -> FxHashMap<String, String> {
     CONVENTIONAL_ALIASES
         .iter()
         .map(|(k, v)| ((*k).to_string(), (*v).to_string()))
-        .collect::<BTreeMap<_, _>>()
+        .collect::<FxHashMap<_, _>>()
 }
 
-fn resolve_aliases(options: Options) -> BTreeMap<String, String> {
+fn resolve_aliases(options: Options) -> FxHashMap<String, String> {
     let mut aliases = match options.aliases {
         Some(options_aliases) => options_aliases,
         None => default_aliases(),
diff --git a/src/fs.rs b/src/fs.rs
index 6da237bedd..ae5cf63d8e 100644
--- a/src/fs.rs
+++ b/src/fs.rs
@@ -1,5 +1,4 @@
 use std::borrow::Cow;
-use std::collections::BTreeSet;
 use std::fs::File;
 use std::io::{BufReader, Read};
 use std::path::{Path, PathBuf};
@@ -8,6 +7,7 @@ use anyhow::{anyhow, Result};
 use globset::GlobMatcher;
 use log::debug;
 use path_absolutize::{path_dedot, Absolutize};
+use rustc_hash::FxHashSet;
 use walkdir::{DirEntry, WalkDir};
 
 use crate::checks::CheckCode;
@@ -83,8 +83,8 @@ pub fn iter_python_files<'a>(
 /// Create tree set with codes matching the pattern/code pairs.
 pub(crate) fn ignores_from_path<'a>(
     path: &Path,
-    pattern_code_pairs: &'a [(GlobMatcher, GlobMatcher, BTreeSet<CheckCode>)],
-) -> Result<BTreeSet<&'a CheckCode>> {
+    pattern_code_pairs: &'a [(GlobMatcher, GlobMatcher, FxHashSet<CheckCode>)],
+) -> Result<FxHashSet<&'a CheckCode>> {
     let (file_path, file_basename) = extract_path_names(path)?;
     Ok(pattern_code_pairs
         .iter()
diff --git a/src/noqa.rs b/src/noqa.rs
index 7e698d91e5..f5e45bfefc 100644
--- a/src/noqa.rs
+++ b/src/noqa.rs
@@ -1,4 +1,3 @@
-use std::collections::{BTreeMap, BTreeSet};
 use std::fs;
 use std::path::Path;
 
@@ -7,6 +6,7 @@ use itertools::Itertools;
 use nohash_hasher::IntMap;
 use once_cell::sync::Lazy;
 use regex::Regex;
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::checks::{Check, CheckCode, REDIRECTS};
 
@@ -83,7 +83,7 @@ pub fn add_noqa(
     checks: &[Check],
     contents: &str,
     noqa_line_for: &IntMap<usize, usize>,
-    external: &BTreeSet<String>,
+    external: &FxHashSet<String>,
 ) -> Result<usize> {
     let (count, output) = add_noqa_inner(checks, contents, noqa_line_for, external);
     fs::write(path, output)?;
@@ -94,16 +94,16 @@ fn add_noqa_inner(
     checks: &[Check],
     contents: &str,
     noqa_line_for: &IntMap<usize, usize>,
-    external: &BTreeSet<String>,
+    external: &FxHashSet<String>,
 ) -> (usize, String) {
-    let mut matches_by_line: BTreeMap<usize, BTreeSet<&CheckCode>> = BTreeMap::new();
+    let mut matches_by_line: FxHashMap<usize, FxHashSet<&CheckCode>> = FxHashMap::default();
     for (lineno, line) in contents.lines().enumerate() {
         // If we hit an exemption for the entire file, bail.
         if is_file_exempt(line) {
             return (0, contents.to_string());
         }
 
-        let mut codes: BTreeSet<&CheckCode> = BTreeSet::new();
+        let mut codes: FxHashSet<&CheckCode> = FxHashSet::default();
         for check in checks {
             if check.location.row() == lineno + 1 {
                 codes.insert(check.kind.code());
@@ -117,7 +117,7 @@ fn add_noqa_inner(
 
         if !codes.is_empty() {
             let matches = matches_by_line.entry(noqa_lineno).or_default();
-            matches.append(&mut codes);
+            matches.extend(codes);
         }
     }
 
@@ -199,9 +199,9 @@ fn add_noqa_inner(
 
 #[cfg(test)]
 mod tests {
-    use std::collections::BTreeSet;
 
     use nohash_hasher::IntMap;
+    use rustc_hash::FxHashSet;
     use rustpython_parser::ast::Location;
 
     use crate::ast::types::Range;
@@ -227,7 +227,7 @@ mod tests {
         let checks = vec![];
         let contents = "x = 1";
         let noqa_line_for = IntMap::default();
-        let external = BTreeSet::default();
+        let external = FxHashSet::default();
         let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for, &external);
         assert_eq!(count, 0);
         assert_eq!(output.trim(), contents.trim());
@@ -241,7 +241,7 @@ mod tests {
         )];
         let contents = "x = 1";
         let noqa_line_for = IntMap::default();
-        let external = BTreeSet::default();
+        let external = FxHashSet::default();
         let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for, &external);
         assert_eq!(count, 1);
         assert_eq!(output.trim(), "x = 1  # noqa: F841".trim());
@@ -264,7 +264,7 @@ mod tests {
         ];
         let contents = "x = 1  # noqa: E741";
         let noqa_line_for = IntMap::default();
-        let external = BTreeSet::default();
+        let external = FxHashSet::default();
         let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for, &external);
         assert_eq!(count, 1);
         assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
@@ -287,7 +287,7 @@ mod tests {
         ];
         let contents = "x = 1  # noqa";
         let noqa_line_for = IntMap::default();
-        let external = BTreeSet::default();
+        let external = FxHashSet::default();
         let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for, &external);
         assert_eq!(count, 1);
         assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
diff --git a/src/pydocstyle/plugins.rs b/src/pydocstyle/plugins.rs
index e909c7a540..884e144a47 100644
--- a/src/pydocstyle/plugins.rs
+++ b/src/pydocstyle/plugins.rs
@@ -1,5 +1,3 @@
-use std::collections::BTreeSet;
-
 use itertools::Itertools;
 use once_cell::sync::Lazy;
 use regex::Regex;
@@ -1402,7 +1400,7 @@ fn missing_args(checker: &mut Checker, definition: &Definition, docstrings_args:
     };
 
     // Look for arguments that weren't included in the docstring.
-    let mut missing_arg_names: BTreeSet<String> = BTreeSet::default();
+    let mut missing_arg_names: FxHashSet<String> = FxHashSet::default();
     for arg in arguments
         .args
         .iter()
diff --git a/src/pyupgrade/plugins/unnecessary_future_import.rs b/src/pyupgrade/plugins/unnecessary_future_import.rs
index 5a2260b90e..510be0bd2b 100644
--- a/src/pyupgrade/plugins/unnecessary_future_import.rs
+++ b/src/pyupgrade/plugins/unnecessary_future_import.rs
@@ -1,6 +1,6 @@
-use std::collections::BTreeSet;
-
+use itertools::Itertools;
 use log::error;
+use rustc_hash::FxHashSet;
 use rustpython_ast::{AliasData, Located};
 use rustpython_parser::ast::Stmt;
 
@@ -38,7 +38,7 @@ pub fn unnecessary_future_import(checker: &mut Checker, stmt: &Stmt, names: &[Lo
     let target_version = checker.settings.target_version;
 
     let mut removable_index: Vec<usize> = vec![];
-    let mut removable_names: BTreeSet<&str> = BTreeSet::new();
+    let mut removable_names: FxHashSet<&str> = FxHashSet::default();
     for (index, alias) in names.iter().enumerate() {
         let name = alias.node.name.as_str();
         if (target_version >= PythonVersion::Py33 && PY33_PLUS_REMOVE_FUTURES.contains(&name))
@@ -53,7 +53,13 @@ pub fn unnecessary_future_import(checker: &mut Checker, stmt: &Stmt, names: &[Lo
         return;
     }
     let mut check = Check::new(
-        CheckKind::UnnecessaryFutureImport(removable_names.into_iter().map(String::from).collect()),
+        CheckKind::UnnecessaryFutureImport(
+            removable_names
+                .into_iter()
+                .map(String::from)
+                .sorted()
+                .collect(),
+        ),
         Range::from_located(stmt),
     );
     if checker.patch(check.kind.code()) {
diff --git a/src/settings/mod.rs b/src/settings/mod.rs
index 629ed8247d..bb55da59de 100644
--- a/src/settings/mod.rs
+++ b/src/settings/mod.rs
@@ -2,12 +2,12 @@
 //! command-line options. Structure is optimized for internal usage, as opposed
 //! to external visibility or parsing.
 
-use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
 use std::path::{Path, PathBuf};
 
 use anyhow::Result;
 use globset::{Glob, GlobMatcher, GlobSet};
+use itertools::Itertools;
 use path_absolutize::path_dedot;
 use regex::Regex;
 use rustc_hash::FxHashSet;
@@ -34,12 +34,12 @@ pub struct Settings {
     pub enabled: FxHashSet<CheckCode>,
     pub exclude: GlobSet,
     pub extend_exclude: GlobSet,
-    pub external: BTreeSet<String>,
+    pub external: FxHashSet<String>,
     pub fixable: FxHashSet<CheckCode>,
     pub format: SerializationFormat,
     pub ignore_init_module_imports: bool,
     pub line_length: usize,
-    pub per_file_ignores: Vec<(GlobMatcher, GlobMatcher, BTreeSet<CheckCode>)>,
+    pub per_file_ignores: Vec<(GlobMatcher, GlobMatcher, FxHashSet<CheckCode>)>,
     pub show_source: bool,
     pub src: Vec<PathBuf>,
     pub target_version: PythonVersion,
@@ -77,7 +77,7 @@ impl Settings {
             ),
             exclude: resolve_globset(config.exclude, project_root)?,
             extend_exclude: resolve_globset(config.extend_exclude, project_root)?,
-            external: BTreeSet::from_iter(config.external),
+            external: FxHashSet::from_iter(config.external),
             fixable: resolve_codes(&config.fixable, &config.unfixable),
             format: config.format,
             flake8_annotations: config.flake8_annotations,
@@ -105,7 +105,7 @@ impl Settings {
             enabled: FxHashSet::from_iter([check_code.clone()]),
             exclude: GlobSet::empty(),
             extend_exclude: GlobSet::empty(),
-            external: BTreeSet::default(),
+            external: FxHashSet::default(),
             fixable: FxHashSet::from_iter([check_code]),
             format: SerializationFormat::Text,
             ignore_init_module_imports: false,
@@ -133,7 +133,7 @@ impl Settings {
             enabled: FxHashSet::from_iter(check_codes.clone()),
             exclude: GlobSet::empty(),
             extend_exclude: GlobSet::empty(),
-            external: BTreeSet::default(),
+            external: FxHashSet::default(),
             fixable: FxHashSet::from_iter(check_codes),
             format: SerializationFormat::Text,
             ignore_init_module_imports: false,
@@ -162,18 +162,23 @@ impl Hash for Settings {
             confusable.hash(state);
         }
         self.dummy_variable_rgx.as_str().hash(state);
-        for value in &self.enabled {
+        for value in self.enabled.iter().sorted() {
             value.hash(state);
         }
-        self.external.hash(state);
-        for value in &self.fixable {
+        for value in self.external.iter().sorted() {
             value.hash(state);
         }
+        for value in self.fixable.iter().sorted() {
+            value.hash(state);
+        }
+        self.ignore_init_module_imports.hash(state);
         self.line_length.hash(state);
         for (absolute, basename, codes) in &self.per_file_ignores {
             absolute.glob().hash(state);
             basename.glob().hash(state);
-            codes.hash(state);
+            for value in codes.iter().sorted() {
+                value.hash(state);
+            }
         }
         self.show_source.hash(state);
         self.target_version.hash(state);
@@ -206,7 +211,7 @@ pub fn resolve_globset(
 pub fn resolve_per_file_ignores(
     per_file_ignores: Vec<PerFileIgnore>,
     project_root: Option<&PathBuf>,
-) -> Result<Vec<(GlobMatcher, GlobMatcher, BTreeSet<CheckCode>)>> {
+) -> Result<Vec<(GlobMatcher, GlobMatcher, FxHashSet<CheckCode>)>> {
     per_file_ignores
         .into_iter()
         .map(|per_file_ignore| {
diff --git a/src/settings/pyproject.rs b/src/settings/pyproject.rs
index 0b2dead26b..2afef70138 100644
--- a/src/settings/pyproject.rs
+++ b/src/settings/pyproject.rs
@@ -96,7 +96,6 @@ pub fn load_options(pyproject: Option<&PathBuf>) -> Result<Options> {
 
 #[cfg(test)]
 mod tests {
-    use std::collections::BTreeMap;
     use std::env::current_dir;
     use std::path::PathBuf;
     use std::str::FromStr;
@@ -432,8 +431,11 @@ other-attribute = 1
                     ban_relative_imports: Some(Strictness::Parents)
                 }),
                 flake8_import_conventions: Some(flake8_import_conventions::settings::Options {
-                    aliases: Some(BTreeMap::from([("pandas".to_string(), "pd".to_string(),)])),
-                    extend_aliases: Some(BTreeMap::from([(
+                    aliases: Some(FxHashMap::from_iter([(
+                        "pandas".to_string(),
+                        "pd".to_string(),
+                    )])),
+                    extend_aliases: Some(FxHashMap::from_iter([(
                         "dask.dataframe".to_string(),
                         "dd".to_string(),
                     )])),
diff --git a/src/settings/types.rs b/src/settings/types.rs
index f38d90e508..3021cc0111 100644
--- a/src/settings/types.rs
+++ b/src/settings/types.rs
@@ -1,4 +1,3 @@
-use std::collections::BTreeSet;
 use std::env;
 use std::hash::Hash;
 use std::path::{Path, PathBuf};
@@ -7,6 +6,7 @@ use std::str::FromStr;
 use anyhow::{anyhow, bail, Result};
 use clap::ValueEnum;
 use globset::{Glob, GlobSetBuilder};
+use rustc_hash::FxHashSet;
 use serde::{de, Deserialize, Deserializer, Serialize};
 
 use crate::checks::CheckCode;
@@ -89,10 +89,10 @@ impl FromStr for FilePattern {
     }
 }
 
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone)]
 pub struct PerFileIgnore {
     pub pattern: String,
-    pub codes: BTreeSet<CheckCode>,
+    pub codes: FxHashSet<CheckCode>,
 }
 
 impl PerFileIgnore {