diff --git a/protocol.txt b/protocol.txt
index 1dc7fc7..826caf4 100644
--- a/protocol.txt
+++ b/protocol.txt
@@ -76,6 +76,7 @@ On error: an 404 http code
 Url: use the request type "request-job" from the configuration answer.
 Parameter as GET or POST:
     * computemethod: What are my computer capability, 0 for using gpu and cpu (the computer is capable of using both but it will not use it at the same time), 1 for cpu only, 2 for gpu only. 
+    * cpu_cores: Number of cores currently available for rendering (optional).
 
 Answer in case of error:
 <?xml version="1.0" encoding="utf-8" ?>
diff --git a/src/com/sheepit/client/Server.java b/src/com/sheepit/client/Server.java
index 6bf5110..edced25 100644
--- a/src/com/sheepit/client/Server.java
+++ b/src/com/sheepit/client/Server.java
@@ -275,7 +275,8 @@ public class Server extends Thread implements HostnameVerifier, X509TrustManager
 		
 		HttpURLConnection connection = null;
 		try {
-			String url = String.format("%s?computemethod=%s", this.getPage("request-job"), this.user_config.computeMethodToInt());
+			OS os = OS.getOS();
+			String url = String.format("%s?computemethod=%s&cpu_cores=%s", this.getPage("request-job"), this.user_config.computeMethodToInt(), ((this.user_config.getNbCores() == -1) ? os.getCPU().cores() : this.user_config.getNbCores()));
 			if (this.user_config.getComputeMethod() != ComputeType.CPU && this.user_config.getGPUDevice() != null) {
 				String gpu_model = "";
 				try {