$ diff -u llil5.ijs llil5p.ijs 
--- llil5.ijs	2023-01-18 09:25:14.041515970 -0600
+++ llil5p.ijs	2023-01-18 09:25:58.889669110 -0600
@@ -9,6 +9,12 @@
 
 pattern =: 0 1
 
+nthrs =: 2!:5 'NUM_THREADS'           NB. get_env NUM_THREADS
+{{
+  if. nthrs do. nthrs =: ".nthrs end. NB. string to integer conversion
+  for. i. nthrs do. 0 T. 0 end.       NB. spin nthrs
+}} ''
+
 args   =: 2 }. ARGV
 fn_out =: {: args
 fn_in  =: }: args
@@ -44,7 +50,7 @@
 read_many_files =: {{
   'fnames pattern' =. y
 
-  ,&.>/"2 (-#pattern) ]\ ,(read_file @:(; &pattern)) "0 fnames
+  ,&.>/"2 (-#pattern) ]\ ,;(read_file @:(; &pattern)) t.'' "0 fnames
 }}
 
 'words nums' =: read_many_files fn_in ; pattern

##</code><code>##

$ diff -u llil5p.ijs llil5tp.ijs 
--- llil5p.ijs	2023-01-18 09:25:58.889669110 -0600
+++ llil5tp.ijs	2023-01-18 09:26:01.553736512 -0600
@@ -21,6 +21,16 @@
 
 filter_CR =: #~ ~: & CR
 
+turbo_mode_ON =: {{
+  assert. 0 <: c =. 8 - {: $y
+  h =. (3 (3!:4) 16be2), ,|."1 [3 (3!:4)"0 (4:,#,1:,#) y
+  3!:2 h, ,y ,"1 _ c # ' '
+}}
+
+turbo_mode_OFF =: {{
+  (5& }. @: (_8& (]\)) @: (2& (3!:1))) &.> y
+}}
+
 read_file =: {{
   'fname pattern' =. y
 
@@ -56,6 +66,7 @@
 'words nums' =: read_many_files fn_in ; pattern
 
 t1 =: (6!:1) ''         NB. time since engine start
+words =: turbo_mode_ON words
 
 idx   =: i.~ words
 nums  =: idx +//. nums
@@ -65,6 +76,7 @@
 nums  =: ~. nums
 'words nums' =: (\: nums)& { &.:>"_1 words ; nums
 
+words =: turbo_mode_OFF words
 t2 =: (6!:1) ''         NB. time since engine start
 
 text =: ; words (, @: (,"1 _))&.(>`a:)"_1 TAB ,. (": ,. nums) ,. LF