diff --git a/pid/pidthread.cpp b/pid/pidthread.cpp
new file mode 100644
index 0000000..38b2516
--- /dev/null
+++ b/pid/pidthread.cpp
@@ -0,0 +1,107 @@
+/**
+ * Copyright 2017 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <chrono>
+#include <map>
+#include <memory>
+#include <thread>
+#include <vector>
+
+#include "pidthread.hpp"
+
+#include "pid/controller.hpp"
+#include "sensors/sensor.hpp"
+
+
+static void ProcessThermals(std::shared_ptr<PIDZone> zone)
+{
+    // Get the latest margins.
+    zone->updateSensors();
+    // Zero out the RPM set point goals.
+    zone->clearRPMSetPoints();
+    // Run the margin PIDs.
+    zone->process_thermals();
+    // Get the maximum RPM set-point.
+    zone->determineMaxRPMRequest();
+}
+
+
+void PIDControlThread(std::shared_ptr<PIDZone> zone)
+{
+    int ms100cnt = 0;
+    /*
+     * This should sleep on the conditional wait for the listen thread to tell
+     * us it's in sync.  But then we also need a timeout option in case
+     * phosphor-hwmon is down, we can go into some weird failure more.
+     *
+     * Another approach would be to start all sensors in worst-case values,
+     * and fail-safe mode and then clear out of fail-safe mode once we start
+     * getting values.  Which I think it is a solid approach.
+     *
+     * For now this runs before it necessarily has any sensor values.  For the
+     * host sensors they start out in fail-safe mode.  For the fans, they start
+     * out as 0 as input and then are adjusted once they have values.
+     *
+     * If a fan has failed, it's value will be whatever we're told or however
+     * we retrieve it.  This program disregards fan values of 0, so any code
+     * providing a fan speed can set to 0 on failure and that fan value will be
+     * effectively ignored.  The PID algorithm will be unhappy but nothing bad
+     * will happen.
+     *
+     * TODO(venture): If the fan value is 0 should that loop just be skipped?
+     * Right now, a 0 value is ignored in FanController::input_proc()
+     */
+#ifdef __TUNING_LOGGING__
+    zone->initializeLog();
+#endif
+    zone->initializeCache();
+    ProcessThermals(zone);
+
+    while (true)
+    {
+        using namespace std::literals::chrono_literals;
+        std::this_thread::sleep_for(0.1s);
+
+        // Check if we should just go back to sleep.
+        if (zone->getManualMode())
+        {
+            continue;
+        }
+
+        // Get the latest fan speeds.
+        zone->updateFanTelemetry();
+
+        if (10 <= ms100cnt)
+        {
+            ms100cnt = 0;
+
+            ProcessThermals(zone);
+        }
+
+        // Run the fan PIDs every iteration.
+        zone->process_fans();
+
+#ifdef __TUNING_LOGGING__
+        zone->getLogHandle() << std::endl;
+#endif
+
+        ms100cnt += 1;
+    }
+
+    return;
+}
+
+