diff --git a/os/build.rs b/os/build.rs
index 4a996053..eb553e5b 100644
--- a/os/build.rs
+++ b/os/build.rs
@@ -6,7 +6,7 @@ fn main() {
     insert_app_data().unwrap();
 }
 
-static TARGET_PATH: &str = "../user/target/riscv64gc-unknown-none-elf/debug/";
+static TARGET_PATH: &str = "../user/target/riscv64gc-unknown-none-elf/release/";
 
 fn insert_app_data() -> Result<()> {
     let mut f = File::create("src/link_app.S").unwrap();
diff --git a/user/Makefile b/user/Makefile
index eabb4b27..5ca334ea 100644
--- a/user/Makefile
+++ b/user/Makefile
@@ -1,5 +1,5 @@
 TARGET := riscv64gc-unknown-none-elf
-MODE := debug
+MODE := release
 APP_DIR := src/bin
 TARGET_DIR := target/$(TARGET)/$(MODE)
 APPS := $(wildcard $(APP_DIR)/*.rs)
diff --git a/user/build.py b/user/build.py
index 1a220881..b558177a 100644
--- a/user/build.py
+++ b/user/build.py
@@ -18,7 +18,7 @@ for app in apps:
             lines.append(line)
     with open(linker, 'w+') as f:
         f.writelines(lines)
-    os.system('cargo build --bin %s' % app)
+    os.system('cargo build --bin %s --release' % app)
     print('[build.py] application %s start with address %s' %(app, hex(base_address+step*app_id)))
     with open(linker, 'w+') as f:
         f.writelines(lines_before)
diff --git a/user/src/bin/00power_3.rs b/user/src/bin/00power_3.rs
index a4b62ab5..064b4e07 100644
--- a/user/src/bin/00power_3.rs
+++ b/user/src/bin/00power_3.rs
@@ -10,7 +10,7 @@ const LEN: usize = 100;
 fn main() -> i32 {
     let p = 3u64;
     let m = 998244353u64;
-    let iter: usize = 100000;
+    let iter: usize = 200000;
     let mut s = [0u64; LEN];
     let mut cur = 0usize;
     s[cur] = 1;
diff --git a/user/src/bin/01power_5.rs b/user/src/bin/01power_5.rs
index dfd27522..157af298 100644
--- a/user/src/bin/01power_5.rs
+++ b/user/src/bin/01power_5.rs
@@ -10,7 +10,7 @@ const LEN: usize = 100;
 fn main() -> i32 {
     let p = 5u64;
     let m = 998244353u64;
-    let iter: usize = 70000;
+    let iter: usize = 140000;
     let mut s = [0u64; LEN];
     let mut cur = 0usize;
     s[cur] = 1;
diff --git a/user/src/bin/02power_7.rs b/user/src/bin/02power_7.rs
index 5cf13696..a5c72dba 100644
--- a/user/src/bin/02power_7.rs
+++ b/user/src/bin/02power_7.rs
@@ -10,7 +10,7 @@ const LEN: usize = 100;
 fn main() -> i32 {
     let p = 7u64;
     let m = 998244353u64;
-    let iter: usize = 80000;
+    let iter: usize = 160000;
     let mut s = [0u64; LEN];
     let mut cur = 0usize;
     s[cur] = 1;