diff --git a/sys/man/8/plan9.ini b/sys/man/8/plan9.ini
index 48aab7f37..61115f7fd 100644
--- a/sys/man/8/plan9.ini
+++ b/sys/man/8/plan9.ini
@@ -720,11 +720,6 @@ processors.
 Prints a summary of the multiprocessor APIC interrupt configuration.
 .SS \fL*nomsi=\fP
 Disables message signaled interrupts.
-.SS \fL*notsc=\fP
-Disables the use of the per processor timestamp counter registers
-as high resolution clock. This option is intended for machines where
-the timestamp counter rate is not constant across cores or is adjusted
-dynamically by power management.
 .SS \fL*pcimaxbno=value\fP
 This puts a limit on the maximum bus number probed
 on a PCI bus (default 7).
diff --git a/sys/src/9/pc/devarch.c b/sys/src/9/pc/devarch.c
index 90cc2f4b9..be29eab3c 100644
--- a/sys/src/9/pc/devarch.c
+++ b/sys/src/9/pc/devarch.c
@@ -797,7 +797,7 @@ cpuidentify(void)
 	/*
 	 *  if there is one, set tsc to a known value
 	 */
-	if((m->cpuiddx & Tsc) != 0 && getconf("*notsc") == nil){
+	if(m->cpuiddx & Tsc){
 		m->havetsc = 1;
 		cycles = _cycles;
 		if(m->cpuiddx & Cpumsr)