diff --git a/README.md b/README.md
index 6fbff96..a57492e 100644
--- a/README.md
+++ b/README.md
@@ -17,11 +17,119 @@ CPU/GPU performance control library for benchmarking
 - [x] Disable GPU turbo (nvidia)
 - [x] Flush addresses from cache (amd64, POWER)
 
-## API
+## Installing
+
+### CMake 
+
+Ensure you have CMake 3.13+.
+
+Add the source tree to your project and then use add_subdirectory
+
+```
+git submodule add git@github.com:cwpearson/perfect.git thirdparty/perfect
+```
+
+`CMakeLists.txt`
+```
+...
+add_subdirectory(thirdparty/perfect)
+...
+target_link_libraries(your-target perfect)
+```
+
+### Without CMake 
+Download the source and add the include directory to your includes and `nvidia-ml` to your link flags
+
+```
+g++ code_using_perfect.cpp -I perfect/include -l nvidia-ml
+nvcc code_using_perfect.cu -I perfect/include
+```
+
+## Usage
+
+The `perfect` functions all return a `perfect::Result`, which is defined in [include/perfect/result.hpp].
+When things are working, it will be `perfect::Result::SUCCESS`.
+A `PERFECT` macro is also defined, which will terminate with an error message unless the `perfect::Result` is `perfect::Result::SUCCESS`.
+
+```c++
+perfect::CpuTurboState state;
+PERFECT(perfect::get_cpu_turbo_state(&state));
+```
+
+### CPU Turbo
+
+`perfect` can enable and disable CPU boost through the Intel p-state mechanism or the ACPI cpufreq mechanism.
+
+See [examples/cpu_turbo.cpp].
 
 
+```c++
+#include "perfect/cpu_turbo.hpp"
+```
+
+* `Result get_cpu_turbo_state(CpuTurboState *state)`
+* `Result set_cpu_turbo_state(CpuTurboState *state)`
+* `Result disable_cpu_turbo()`
+* `Result enable_cpu_turbo()`
+* `bool is_turbo_enabled(CpuTurboState state)`
+
+### OS Performance
+
+`perfect` can control the OS governor on linux.
+
+See [examples/os_perf.cpp].
+
+```c++
+#include "perfect/os_perf.hpp"
+```
+
+* `Result get_os_perf_state(OsPerfState *state, const int cpu)`: Save the current OS governor mode for CPU `cpu`.
+* `Result os_perf_state_maximum(const int cpu)`: Set the OS governor to it's maximum performance mode.
+* `Result set_os_perf_state(const int cpu, OsPerfState state)`: Restore a previously-saved OS governor mode.
+
+### GPU Turbo
+
+`perfect` can enable/disable GPU turbo boost.
+
+See [examples/gpu_turbo.cu]
+
+```c++
+#include "perfect/gpu_turbo.hpp"
+```
+
+* `Result get_gpu_turbo_state(GpuTurboState *state, unsigned int idx)`: Get the current turbo state for GPU `idx`, useful to restore later.
+* `bool is_turbo_enabled(GpuTurboState state)`: Check if turbo is enabled.
+* `Result set_gpu_turbo_state(GpuTurboState state, unsigned int idx)`: Set a previously saved turbo state.
+* `Result disable_gpu_turbo(unsigned int idx)`: Disable GPU `idx` turbo.
+* `Result enable_gpu_turbo(unsigned int idx)`: Enable GPU `idx` turbo.
+
+### GPU Clocks
+
+`perfect` can lock GPU clocks to their maximum values.
+
+See [examples/gpu_clocks.cu]
+
+```c++
+#include "perfect/gpu_clocks.hpp`
+```
+
+* `Result set_max_gpu_clocks(unsigned int idx)`: Set GPU `idx` clocks to their maximum reported values.
+* `Result reset_gpu_clocks(unsigned int idx)`: Unset GPU `idx` clocks.
+
+### CPU Cache
+
+`perfect` can flush data from CPU caches. Unlike the other APIs, these do not return a `Result` because they do not fail.
+
+See [examples/cpu_cache.cpp].
+
+```c++
+#include "perfect/cpu_cache.hpp`
+```
+
+* `void flush_all(void *p, const size_t n)`: Flush all cache lines starting at `p` for `n` bytes.
 
 ## Wish List
 
+- [ ] Make CUDA Optional
 - [ ] Nvidia GPU power monitoring
 - [ ] Nivida GPU utilization monitoring
\ No newline at end of file
diff --git a/examples/cpu_turbo.cpp b/examples/cpu_turbo.cpp
index a269c23..a3410ca 100644
--- a/examples/cpu_turbo.cpp
+++ b/examples/cpu_turbo.cpp
@@ -3,6 +3,7 @@
 #include "perfect/cpu_turbo.hpp"
 
 int main(void) {
+  perfect::init();
 
   perfect::Result ret;
   perfect::CpuTurboState state;
diff --git a/examples/gpu_clocks.cu b/examples/gpu_clocks.cu
index 3d2d2ef..79ce449 100644
--- a/examples/gpu_clocks.cu
+++ b/examples/gpu_clocks.cu
@@ -4,9 +4,7 @@
 #include "perfect/init.hpp"
 
 int main(void) {
-
     using namespace perfect;
-
     init();
 
     for (unsigned int gpu = 0; gpu < 1; ++gpu) {
diff --git a/examples/gpu_turbo.cu b/examples/gpu_turbo.cu
index dfd7fc0..4672cf0 100644
--- a/examples/gpu_turbo.cu
+++ b/examples/gpu_turbo.cu
@@ -4,12 +4,11 @@
 #define OR_DIE(expr)
 
 int main(void) {
-
   using namespace perfect;
-  GpuTurboState state;
-
   init();
 
+  GpuTurboState state;
+
   for (unsigned int gpu = 0; gpu < 1; ++gpu) {
     PERFECT(perfect::get_gpu_turbo_state(&state, gpu));
     PERFECT(perfect::disable_gpu_turbo(gpu));
diff --git a/examples/os_perf.cpp b/examples/os_perf.cpp
index b8b59a6..a0342fc 100644
--- a/examples/os_perf.cpp
+++ b/examples/os_perf.cpp
@@ -3,7 +3,7 @@
 #include <map>
 
 int main(void) {
-
+    perfect::init();
 
     std::map<int, perfect::OsPerfState> states;
 
diff --git a/include/perfect/cpu_cache.hpp b/include/perfect/cpu_cache.hpp
index b28e85c..09eb410 100644
--- a/include/perfect/cpu_cache.hpp
+++ b/include/perfect/cpu_cache.hpp
@@ -24,6 +24,8 @@ Routines for controlling CPU caching
 #error "unsupported CPU arch"
 #endif
 
+#include "init.hpp"
+
 namespace perfect {
 
 inline void flush_all(void *p, const size_t n) {
diff --git a/include/perfect/cpu_turbo.hpp b/include/perfect/cpu_turbo.hpp
index 577cc06..d5be0f1 100644
--- a/include/perfect/cpu_turbo.hpp
+++ b/include/perfect/cpu_turbo.hpp
@@ -15,6 +15,7 @@
 #error "unsupported OS"
 #endif
 
+#include "init.hpp"
 #include "result.hpp"
 
 namespace perfect {
diff --git a/include/perfect/gpu_clocks.hpp b/include/perfect/gpu_clocks.hpp
index 6cf4226..8c97887 100644
--- a/include/perfect/gpu_clocks.hpp
+++ b/include/perfect/gpu_clocks.hpp
@@ -4,6 +4,9 @@
 
 #include "detail/nvidia/nvidia-ml.hpp"
 
+#include "result.hpp"
+#include "init.hpp"
+
 namespace perfect {
 
 /*!
diff --git a/include/perfect/gpu_turbo.hpp b/include/perfect/gpu_turbo.hpp
index 6203a77..58c956f 100644
--- a/include/perfect/gpu_turbo.hpp
+++ b/include/perfect/gpu_turbo.hpp
@@ -3,6 +3,7 @@
 #include "detail/nvidia/nvidia-ml.hpp"
 
 #include "result.hpp"
+#include "init.hpp"
 
 namespace perfect {
 
diff --git a/include/perfect/os_perf.hpp b/include/perfect/os_perf.hpp
index d3ba39d..e35128f 100644
--- a/include/perfect/os_perf.hpp
+++ b/include/perfect/os_perf.hpp
@@ -1,13 +1,9 @@
 #pragma once
 
-
-
 #include <vector>
 #include <string>
 #include <cassert>
 
-
-
 #ifdef __linux__
 #include "detail/os/linux.hpp"
 #else
@@ -15,6 +11,7 @@
 #endif
 
 #include "result.hpp"
+#include "init.hpp"
 
 namespace perfect {
 
diff --git a/tools/enable_turbo.cpp b/tools/enable_turbo.cpp
index ca97206..9465260 100644
--- a/tools/enable_turbo.cpp
+++ b/tools/enable_turbo.cpp
@@ -1,7 +1,6 @@
 #include <iostream>
 
 #include "perfect/cpu_turbo.hpp"
-#include "perfect/init.hpp"
 
 using namespace perfect;