diff --git a/HCL.md b/HCL.md
index e26b30fc..394e7dfb 100644
--- a/HCL.md
+++ b/HCL.md
@@ -34,9 +34,9 @@ Specific systems tested by Qubes core developers
 
 -   Lenovo Thinkpad T420 w/ Intel graphics
 -   Lenovo Thinkpad T420s w/ Intel graphics (requires 2.3.7 kernel to handle the panel screen correctly)
--   Lenovo Thinkpad T61 w/ Nvidia graphics (Quadro NVS 140M) - works well (using xenlinux 2.6.38 kernel), better stability with [nvidia binary drivers](/wiki/InstallNvidiaDriver) - especially when using external monitor
+-   Lenovo Thinkpad T61 w/ Nvidia graphics (Quadro NVS 140M) - works well (using xenlinux 2.6.38 kernel), better stability with [nvidia binary drivers](/wiki/InstallNvidiaDriver) - especially when using external monitor. This system doesn't support VT-d!
 
--   Samsung X460 - works well on both xenlinux 2.6.38 and pvops 3.2.7 kernel; after resume ethernet driver (sky2) need to be reloaded in netvm to start working again
+-   Samsung X460 - works well on both xenlinux 2.6.38 and pvops 3.2.7 kernel; after resume ethernet driver (sky2) need to be reloaded in netvm to start working again. Even though the chipset suppors VT-d, the BIOS is broken, and so the VT-d is not picked up by Xen, so it effectively doesn't work.
 
 -   Sony Vaio Z 12 -- works well, but some [tinkering required](/wiki/SonyVaioTinkering)