diff --git a/Cargo.lock b/Cargo.lock
index 2f48fb3..79bf332 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -48,11 +48,28 @@ dependencies = [
  "byteorder",
 ]
 
+[[package]]
+name = "libc"
+version = "0.2.152"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13e3bf6590cbc649f4d1a3eefc9d5d6eb746f5200ffb04e5e142700b8faa56e7"
+
+[[package]]
+name = "memmap"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6585fd95e7bb50d6cc31e20d4cf9afb4e2ba16c5846fc76793f11218da9c475b"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "onebrc"
 version = "0.1.0"
 dependencies = [
  "fxhash",
+ "memmap",
  "rayon",
 ]
 
@@ -75,3 +92,25 @@ dependencies = [
  "crossbeam-deque",
  "crossbeam-utils",
 ]
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
diff --git a/Cargo.toml b/Cargo.toml
index 5d2d6f0..c5e30c4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,4 +5,5 @@ edition = "2021"
 
 [dependencies]
 fxhash = "0.2.1"
+memmap = "0.7.0"
 rayon = "1.8.0"
diff --git a/README.md b/README.md
index 01ee63d..c2965cb 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,11 @@
 # One billion row challenge
 
-* Fastest single threaded runtime: 29.7s (4.5s to read the file into memory, 24s to process rows and ~150micros to generate the output)
+These tests were run on a machine with r9 5900x, 64gb memory.
+
+
+* single threaded, no mmap: 29.7s (4.5s to read the file into memory, 24s to process rows and ~150micros to generate the output)
+
+* multi threaded, no mmap: read = 4.682276171s processed = 2.057576429s output_gen = 188.113µs
+
+* multi threaded + mmap: read = 5.75µs processed = 2.144708s output_gen = 276.73µs
 
-* Fastest multi threaded runtime on a machine with 12 cores: read = 4.682276171s processed = 2.057576429s output_gen = 188.113µs
diff --git a/src/main.rs b/src/main.rs
index 676f712..75984d8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,16 +1,18 @@
 use fxhash::FxHashMap;
+use memmap::MmapOptions;
 use rayon::prelude::*;
-use std::{fs::File, io::Read, time::Instant};
+use std::{fs::File, time::Instant};
 
 fn main() {
-    let mut buf = Vec::new();
-
     let t1 = Instant::now();
 
-    let mut file = File::open("./measurements.txt").expect("error in opening file");
+    let file = File::open("./measurements.txt").expect("error in opening file");
 
-    file.read_to_end(&mut buf)
-        .expect("error in reading file to memory");
+    let buf = unsafe {
+        MmapOptions::new()
+            .map(&file)
+            .expect("error in mmaping file")
+    };
 
     let t1_elapsed = t1.elapsed();