diff --git a/README.adoc b/README.adoc
index 2539328..054ae9a 100644
--- a/README.adoc
+++ b/README.adoc
@@ -2512,11 +2512,13 @@ The biggest time hog is always GCC, can we use a precompiled one? https://stacko
 
 ===== Benchmark machines
 
+The build times are calculated after doing link:https://buildroot.org/downloads/manual/manual.html#_offline_builds[`make source`], which downloads the sources, and basically benchmarks the Internet.
+
 ====== P51
 
-Build time at 2c12b21b304178a81c9912817b782ead0286d282: 30 minutes
+Build time at 2c12b21b304178a81c9912817b782ead0286d282: 28 minutes
 
-Lenovo link:https://www3.lenovo.com/gb/en/laptops/thinkpad/p-series/P51/p/22TP2WPWP51[P51 laptop]:
+Lenovo ThinkPad link:https://www3.lenovo.com/gb/en/laptops/thinkpad/p-series/P51/p/22TP2WPWP51[P51 laptop]:
 
 * 2500 USD in 2018 (high end)
 * Intel Core i7-7820HQ Processor (8MB Cache, up to 3.90GHz) (4 cores 8 threads)
@@ -2534,9 +2536,12 @@ TODO specs, SHA.
 
 ====== 38Mbps
 
-Shallow clone of all submodules at 2c12b21b304178a81c9912817b782ead0286d282: 4 minutes.
+2c12b21b304178a81c9912817b782ead0286d282:
 
-Google M-lab speed test 36.4Mbps
+* shallow clone of all submodules: 4 minutes.
+* `make source`: 2 minutes
+
+Google M-lab speed test: 36.4Mbps
 
 === About