diff --git a/README.md b/README.md
index b440684..83eaf93 100644
--- a/README.md
+++ b/README.md
@@ -32,21 +32,38 @@ wget https://fate-suite.libav.org/h264-conformance/AUD_MW_E.264
 cd ..
 ```
 
+**NOTE:** In each of the following, if you have a multi-card host system
+you may need to change the qsv_device used by changing QSV_DEVICE
+to whichever node is connected to your hardware.
+
+You can find out the paths via:
+```
+ls -l /dev/dri/by-path/pci-*$(lspci | grep Intel.*Graphics | cut -d " " -f1)*
+```
+
+On my system, my Intel graphics adapter is /dev/dri/renderD129, so I use:
+
+```
+export QSV_DEVICE=/dev/dri/renderD129
+```
+
 ## Decode
 
 H264 video decode and save as raw file:
 
 ### Connect to container
 ```bash
+QSV_DEVICE=${QSV_DEVICE:-/dev/dri/renderD128}
 docker run \
   --rm \
   --device=/dev/dri \
   --volume $(pwd)/media:/media \
   -it \
   intel-media-ffmpeg \
-  ffmpeg -hwaccel qsv -c:v h264_qsv -i /media/AUD_MW_E.264  \
-       -vf hwdownload,format=nv12 -pix_fmt yuv420p          \
-       /media/AUD_MW.yuv
+  ffmpeg -hwaccel qsv -qsv_device ${QSV_DEVICE} \
+    -c:v h264_qsv -i /media/AUD_MW_E.264        \
+    -vf hwdownload,format=nv12 -pix_fmt yuv420p \
+    /media/AUD_MW.yuv
 ```
 
 ### Encode
@@ -54,6 +71,7 @@ docker run \
 Encode a 10 frames of 720p raw input as H264 with 5Mbps using VBR mode:
 
 ```bash
+QSV_DEVICE=${QSV_DEVICE:-/dev/dri/renderD128}
 docker run \
   --rm \
   --device=/dev/dri \
@@ -73,27 +91,30 @@ docker run \
 H264 decode && H265 encode with 5Mbps using VBR
 
 ```bash
+QSV_DEVICE=${QSV_DEVICE:-/dev/dri/renderD128}
 docker run \
   --rm \
   --device=/dev/dri \
   --volume $(pwd)/media:/media \
   -it \
   intel-media-ffmpeg \
-  ffmpeg -hwaccel qsv -c:v h264_qsv -i /media/AUD_MW_E.264 \
-       -c:v hevc_qsv -b:v 5M AUD_MW_E.hevc
+  ffmpeg -hwaccel qsv -qsv_device ${QSV_DEVICE} \
+    -c:v h264_qsv -i /media/AUD_MW_E.264        \
+    -c:v hevc_qsv -b:v 5M AUD_MW_E.hevc
 ```
 
 1:N transcoding
 
 ```bash
+QSV_DEVICE=${QSV_DEVICE:-/dev/dri/renderD128}
 docker run \
   --rm \
   --device=/dev/dri \
   --volume $(pwd)/media:/media \
   -it \
   intel-media-ffmpeg \
-  ffmpeg -hwaccel qsv -c:v h264_qsv                    \
-    -i /media/AUD_MW_E.264                             \
+  ffmpeg -hwaccel qsv -qsv_device ${QSV_DEVICE}        \
+    -c:v h264_qsv -i /media/AUD_MW_E.264               \
     -filter_complex "split=2[s1][s2];                  \
                      [s1]scale_qsv=1280:720[o1];       \
                      [s2]vpp_qsv=framerate=60[o2]"     \