diff --git a/src/config/basic_client.rs b/src/config/basic_client.rs
index 4581d5c..4ded7a2 100644
--- a/src/config/basic_client.rs
+++ b/src/config/basic_client.rs
@@ -6,12 +6,12 @@ use crate::config::KeyCheckerConfig;
 
 pub fn client_builder(config: &KeyCheckerConfig) -> Result<Client, reqwest::Error> {
     // Adjust connection pool size based on concurrency, optimizing for 0.5 second response time
-    let pool_size = (config.concurrency / 2).max(20).min(config.concurrency);
+    let pool_size = config.concurrency / 2;
 
     let mut builder = Client::builder()
         .timeout(Duration::from_secs(config.timeout_sec))
-        .pool_max_idle_per_host(pool_size)
-        .http2_prior_knowledge();
+        .pool_max_idle_per_host(pool_size);
+//        .http2_prior_knowledge();
 
     if let Some(ref proxy_url) = config.proxy {
         builder = builder.proxy(reqwest::Proxy::all(proxy_url.clone())?);