diff --git a/MC/config/PWGGAJE/external/generator/generator_pythia8_powheg.C b/MC/config/PWGGAJE/external/generator/generator_pythia8_powheg.C
index 6ca884dda..5c3afd206 100644
--- a/MC/config/PWGGAJE/external/generator/generator_pythia8_powheg.C
+++ b/MC/config/PWGGAJE/external/generator/generator_pythia8_powheg.C
@@ -4,6 +4,7 @@ R__ADD_INCLUDE_PATH($O2DPG_MC_CONFIG_ROOT)
 #include "Pythia8/Pythia.h"
 #include "Generators/GeneratorPythia8Param.h"
 #include "CommonUtils/FileSystemUtils.h"
+#include <thread>
 // Pythia8 generator with POWHEG
 //
 // Author: Marco Giacalone (marco.giacalone@cern.ch)
@@ -13,7 +14,7 @@ R__ADD_INCLUDE_PATH($O2DPG_MC_CONFIG_ROOT)
    generator/generator_pythia8_powheg.C;GeneratorExternal.funcName=\
    getGeneratorJEPythia8POWHEG(\"powheg.input\",\"${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGGAJE/pythia8/generator/pythia8_powheg.cfg\")"
 // or with iniFile
-// o2-sim -g external --noGeant -n 2 -j 8 --configFile $O2DPG_MC_CONFIG_ROOT/MC/config/PWGGAJE/ini/GeneratorPythia8POWHEG.ini
+// o2-sim -g external --noGeant -n 2 -j 8 --configFile $O2DPG_MC_CONFIG_ROOT/MC/config/PWGGAJE/ini/GeneratorPythia8POWHEG_beauty.ini
 
 namespace o2
 {
@@ -22,10 +23,11 @@ namespace eventgen
 
 using namespace Pythia8;
 
-// Pythia8 generator using POWHEG data that are generated during the initialization
-// of the external generator. The POWHEG configuration file is copied to the current
-// directory with the right name and the POWHEG events are generated using the executable
-// specified via the type parameter, namely:
+// Pythia8 generator using POWHEG data that are generated partially during the initialization
+// of the external generator and then during the generateEvent when mNMaxPerJob is reached. The first time
+// all the configuration files are created so that the other jobs can be run much faster (and in parallel in the future)
+// The POWHEG configuration file is copied to the current directory with the right name and the POWHEG events are generated
+// using the executable specified via the type parameter, namely:
 //    0: pwhg_main_hvq
 //    1: pwhg_main_W
 //    2: pwhg_main_Z
@@ -35,7 +37,7 @@ class GeneratorJEPythia8POWHEG : public o2::eventgen::GeneratorPythia8
 {
 public:
   /// default constructor
-  GeneratorJEPythia8POWHEG(std::string confpath = "pwgpath", short int type = 0)
+  GeneratorJEPythia8POWHEG(std::string confpath = "pwgpath", short int type = 0, int maxEventsPerJob = 50)
   {
     // Assign events to generate with POWHEG
     unsigned int nPowhegEvents = getTotalNEvents();
@@ -43,23 +45,58 @@ public:
       LOG(fatal) << "Number of events not set or set to 0.";
       exit(1);
     }
-    // Check on nEvents to generate with POWHEG
-    // due to integer limit hardcoded in the generator
-    if (nPowhegEvents > std::numeric_limits<int>::max()) {
-      LOG(fatal) << "Number of events for POWHEG exceeds the maximum allowed value";
+    // POWHEG has an integer limit hardcoded for the nEvents, but
+    // with the multiple jobs setup this is not an issue (an error will automatically be thrown)
+    mNMaxPerJob = maxEventsPerJob;
+    if (mNMaxPerJob < 1) {
+      LOG(fatal) << "Number of events per job are set to 0 or lower.";
       exit(1);
     }
+    mNFiles = nPowhegEvents / mNMaxPerJob;
+    if (nPowhegEvents % mNMaxPerJob != 0)
+    {
+      mNFiles++;
+    }
+    gRandom->SetSeed(0);
+    if(!confMaker(confpath))
+    {
+      LOG(fatal) << "Failed to edit POWHEG configuration file";
+      exit(1);
+    }
+    mPowhegConf = confpath;
+    // Get POWHEG executable to use
+    if (type >= mPowhegGen.size()) {
+      LOG(warn) << "Available POWHEG generators are:";
+      for (int k = 0; k < mPowhegGen.size(); k++)
+      {
+        LOG(warn) << "\t" << k << ": " << mPowhegGen[k];
+      }
+      LOG(fatal) << "POWHEG generator type " << type << " not found";
+      exit(1);
+    } else {
+      LOG(info) << "Running POWHEG using the " << mPowhegGen[type] << " executable";
+      // Generate the POWHEG events
+      mExePOW = mPowhegGen[type] + " &";
+      system(mExePOW.c_str());
+    }
+  };
+
+  Bool_t confMaker(std::string confpath = "pwgpath", bool parallel = false)
+  {
     // Check if file exist and is not empty
     if (std::filesystem::exists(confpath) && std::filesystem::file_size(confpath) > 0) {
       // Copy the file to the current directory
       ifstream src(confpath);
       ofstream dst("powheg.input");
-      gRandom->SetSeed(0);
       int seed = gRandom->Integer(900000000);
       bool isseed = false;
       bool isnumevts = false;
+      if (mCurrFile == mNFiles - 1 && getTotalNEvents() % mNMaxPerJob != 0) {
+        mNMaxPerJob = getTotalNEvents() % mNMaxPerJob;
+      }
       std::string line;
-      while (std::getline(src, line)) {
+      while (std::getline(src, line))
+      {
         if (line.find("iseed") != std::string::npos)
         {
           // Set the seed to the random number
@@ -69,42 +106,129 @@ public:
         if (line.find("numevts") != std::string::npos)
         {
           // Set the number of events to the number of events defined in the configuration
-          line = "numevts " + std::to_string(nPowhegEvents);
+          line = "numevts " + std::to_string(mNMaxPerJob);
           // replace it in the file
           isnumevts = true;
         }
         dst << line << std::endl;
       }
-      if (!isseed) {
+      if (!isseed)
+      {
         dst << "iseed " << seed << std::endl;
       }
-      if (!isnumevts) {
-        dst << "numevts " << nPowhegEvents << std::endl;
+      if (!isnumevts)
+      {
+        dst << "numevts " << mNMaxPerJob << std::endl;
+      }
+      if (parallel)
+      {
+        dst << "manyseeds 1" << std::endl; // Enables the usage of pwgseeds.dat file to set the seed in parallel mode
+        dst << "parallelstage 4" << std::endl; // Allows event generation based on pre-generated POWHEG configuration files (needed for certain configurations)
       }
       src.close();
       dst.close();
     } else {
       LOG(fatal) << "POWHEG configuration file not found or empty" << std::endl;
-      exit(1);
+      return false;
     }
-    // Get POWHEG executable to use
-    if (type >= mPowhegGen.size()) {
-      LOG(warn) << "Available POWHEG generators are:";
-      for (int k = 0; k < mPowhegGen.size(); k++)
-      {
-        LOG(warn) << "\t" << k << ": " << mPowhegGen[k];
+    return true;
+  }
+
+  Bool_t startPOW() 
+  {
+    if(mCurrFile == 1) {
+      if (!confMaker(mPowhegConf, true)) {
+        LOG(fatal) << "Failed to edit POWHEG configuration with parallelisation";
+        return false;
       }
-      LOG(fatal) << "POWHEG generator type " << type << " not found";
-      exit(1);
+    }
+    LOG(info) << "Starting POWHEG job " << mCurrFile+1 << " of " << mNFiles;
+    system(("echo " + std::to_string(mCurrFile - 1) + " | " + mExePOW).c_str());
+    return true;
+  }
+
+  Bool_t checkEOF() {
+    // Check if the POWHEG generation is done
+    int result = system(("grep -q /LesHouchesEvents " + mLHEFoutput).c_str());
+    if (result == 0)
+    {
+      return true;
     } else {
-      LOG(info) << "Running POWHEG using the " << mPowhegGen[type] << " executable";
-      // Generate the POWHEG events
-      system(mPowhegGen[type].c_str());
+      return false;
+    }
+  }
+
+  Bool_t POWchecker() {
+    // Check if the POWHEG events file exists
+    LOG(info) << "Waiting for " << mLHEFoutput << " to exist";
+    while (!std::filesystem::exists(mLHEFoutput.c_str()))
+    {
+      std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    }
+    LOG(info) << "POWHEG events file for job " << mCurrFile << " found";
+    while (!checkEOF())
+    {
+      std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    }
+    LOG(info) << "POWHEG events ready";
+    return true;
+  }
+
+  // Check for the POWHEG events file existance
+  Bool_t Init() override
+  {
+    // Check if the POWHEG events file exists
+    if(POWchecker()) {
+      return GeneratorPythia8::Init();
+    } else {
+      return false;
+    }
+  };
+
+  // Set Generator ReadEvent to wait for the POWHEG events
+  Bool_t generateEvent() override
+  {
+    /** Reinitialise when EOF is reached **/
+    if (mPythia.info.atEndOfFile())
+    {
+      if(mCurrFile == 0)
+      {
+        mPythia.readString("Beams:newLHEFsameInit = on");
+        // Create pwgseeds.dat file with a random seed for each line
+        std::ofstream seedfile("pwgseeds.dat");
+        for (int i = 0; i < mNFiles - 1; i++)
+        {
+          seedfile << gRandom->Integer(900000000) << std::endl;
+        }
+        seedfile.close();
+      }
+      mCurrFile++;
+      mLHEFoutput = Form("pwgevents-%04d.lhe", mCurrFile - 1);
+      mPythia.readString(Form("Beams:LHEF = %s", mLHEFoutput.c_str()));
+      if(!startPOW())
+      { 
+        return false;
+      }
+      if (POWchecker()) {
+        // If Pythia fails to initialize, exit with error.
+        if (!mPythia.init())
+        {
+          LOG(fatal) << "Failed to init \'Pythia8\': init returned with error";
+          return false;
+        }
+      }
     }
+    return GeneratorPythia8::generateEvent();
   };
 
 private:
   const std::vector<std::string> mPowhegGen = {"pwhg_main_hvq", "pwhg_main_W", "pwhg_main_Z", "pwhg_main_dijet", "pwhg_main_directphoton"}; // POWHEG executables
+  short int mNFiles = 1;
+  short int mCurrFile = 0;
+  std::string mExePOW = "";
+  std::string mPowhegConf = "";
+  std::string mLHEFoutput = "pwgevents.lhe";
+  int mNMaxPerJob = 50;
 };
 
 } // namespace eventgen
@@ -112,13 +236,13 @@ private:
 
 /** generator instance and settings **/
 
-FairGenerator *getGeneratorJEPythia8POWHEG(std::string powhegconf = "pwgpath", std::string pythia8conf = "", short int type = 0)
+FairGenerator *getGeneratorJEPythia8POWHEG(std::string powhegconf = "pwgpath", std::string pythia8conf = "", short int type = 0, int maxEventsPerJob = 1e4)
 {
   using namespace o2::eventgen;
   // Expand paths for the POWHEG configuration file
   powhegconf = o2::utils::expandShellVarsInFileName(powhegconf);
   LOG(info) << "Using POWHEG configuration file: " << powhegconf;
-  auto myGen = new GeneratorJEPythia8POWHEG(powhegconf, type);
+  auto myGen = new GeneratorJEPythia8POWHEG(powhegconf, type, maxEventsPerJob);
   if(GeneratorPythia8Param::Instance().config.empty() && pythia8conf.empty()) {
     LOG(fatal) << "No configuration provided for Pythia8";
   }
@@ -131,4 +255,4 @@ FairGenerator *getGeneratorJEPythia8POWHEG(std::string powhegconf = "pwgpath", s
     myGen->setConfig(pythia8conf);
   }
   return myGen;
-}
\ No newline at end of file
+}
diff --git a/test/run_generator_tests.sh b/test/run_generator_tests.sh
index 551f61261..c977f49c1 100755
--- a/test/run_generator_tests.sh
+++ b/test/run_generator_tests.sh
@@ -161,8 +161,11 @@ add_ini_files_from_macros()
     # given a list of macros, collect all INI files which contain at least one of them
     local macro_files=$@
     for mf in ${macro_files} ; do
-        # if any, strip the leading O2DPG_ROOT path to only grep for the relative trailing path
-        mf=${mf##${O2DPG_ROOT}/}
+        # Strip anything before MC/config/, if any, to get the macro relative path
+        if [[ "${mf}" == *"MC/config"* ]] ; then
+            mf=${mf#*MC/config/}
+            mf="MC/config/${mf}"
+        fi
         local other_ini_files=$(grep -r -l ${mf} | grep ".ini$")
         # so this macro is not included in any of the INI file,
         # maybe it is included by another macro which is then included in an INI file