diff --git a/core-buffer/include/buffer_config.hpp b/core-buffer/include/buffer_config.hpp
index bb0e075..f98750f 100644
--- a/core-buffer/include/buffer_config.hpp
+++ b/core-buffer/include/buffer_config.hpp
@@ -28,7 +28,11 @@ namespace core_buffer {
     // Size of sf_buffer RB in elements.
     const size_t BUFFER_RB_SIZE = 1000;
 
-    const int WRITER_ZMQ_IO_THREADS = 16;
+    // ZMQ threads for receiving data from sf_replay.
+    const int WRITER_ZMQ_IO_THREADS = 4;
+
+    // Size of buffer between the receiving and writing part of sf_writer
+    const int WRITER_RB_BUFFER_SLOTS = 100;
 
     // How many frames to buffer before flushing to file.
     const size_t WRITER_BUFFER_SIZE = 100;
diff --git a/sf-buffer/src/sf_writer.cpp b/sf-buffer/src/sf_writer.cpp
index e41af06..52e6ef7 100644
--- a/sf-buffer/src/sf_writer.cpp
+++ b/sf-buffer/src/sf_writer.cpp
@@ -136,7 +136,7 @@ int main (int argc, char *argv[])
 
     size_t n_modules = 32;
 
-    RingBuffer<DetectorFrame> ring_buffer(10);
+    RingBuffer<DetectorFrame> ring_buffer(WRITER_RB_BUFFER_SLOTS);
     ring_buffer.initialize(MODULE_N_BYTES*n_modules);
 
     string ipc_prefix = "ipc://sf-replay-";