And the same benchmark in FORTRAN IV (test 1.b from above link).
Code:
.CREATE TEST.FT
#?
#A
C SIGH, THOSE WERE THE DAYS
DIMENSION A(4,500)
N = 500
..
#L
C SIGH, THOSE WERE THE DAYS
DIMENSION A(4,500)
N = 500
WRITE (4,400)
400 FORMAT (' START')
X = 0.01
J = 2
DO 100 I = 1,N
A(1,I) = X
Y = SQRT(X)
A(J,I) = Y
Y = SIN(X)
A(J+1,I) = Y
Y = ALOG(X)
A(J+2,I) = Y
X = X + 0.01
100 CONTINUE
WRITE (4,404)
404 FORMAT(' END')
WRITE (4,440)
C 1 2 3 4 5
C 123456789a123456789b123456789c123456789d123456789e12
440 FORMAT(' # X SQRT SIN N-LOG')
DO 110 I = 1,17
WRITE (4,444) I, A(1,I), A(2,I), A(3,I), A(4,I)
444 FORMAT(I3,F7.3,3X,3(F13.9,2X))
110 CONTINUE
STOP
END
#?
#E
.
.R F4
*
*TEST/G$
START
END
# X SQRT SIN N-LOG
1 0.010 0.100000023 0.009999170 -4.605169296
2 0.020 0.141421377 0.019998097 -3.912022709
3 0.030 0.173205137 0.029995018 -3.506557941
4 0.040 0.199999988 0.039988934 -3.218876123
5 0.050 0.223606824 0.049978864 -2.995732426
6 0.060 0.244948923 0.059963786 -2.813410758
7 0.070 0.264575123 0.069942712 -2.659260034
8 0.080 0.282842695 0.079914629 -2.525728940
9 0.090 0.299999952 0.089877808 -2.407945394
10 0.100 0.316227674 0.099832785 -2.302585244
11 0.110 0.331662416 0.109777808 -2.207275629
12 0.120 0.346410095 0.119711756 -2.120264172
13 0.130 0.360554993 0.129633784 -2.040220499
14 0.140 0.374165654 0.139542877 -1.966113448
15 0.150 0.387298226 0.149437963 -1.897120475
16 0.160 0.399999916 0.159317374 -1.832582354
17 0.170 0.412310421 0.169181585 -1.771957278
.
The same timing, ~1sec..
PDP-8/XC6 - the Mainframe in '65

I modded the above test such it runs 50x in a loop, thus we can measure the elapsed time better.
Code:
#L
C SIGH, THOSE WERE THE DAYS
C MODDED BY PITO 11/2016
C WE LOOP THE TEST 50X
DIMENSION A(4,500)
L = 50
N = 500
WRITE (4,400)
400 FORMAT (' START')
DO 200 M = 1,L
X = 0.01
J = 2
DO 100 I = 1,N
A(1,I) = X
Y = SQRT(X)
A(J,I) = Y
Y = SIN(X)
A(J+1,I) = Y
Y = ALOG(X)
A(J+2,I) = Y
X = X + 0.01
100 CONTINUE
200 CONTINUE
WRITE (4,404)
404 FORMAT(' END')
WRITE (4,440)
C 1 2 3 4 5
C 123456789a123456789b123456789c123456789d123456789e12
440 FORMAT(' # X SQRT SIN N-LOG')
DO 110 I = 1,17
WRITE (4,444) I, A(1,I), A(2,I), A(3,I), A(4,I)
444 FORMAT(I3,F7.3,3X,3(F13.9,2X))
110 CONTINUE
STOP
END
#?
#E
.
.R F4
*
*SHRUD1/G$
START
END
# X SQRT SIN N-LOG
1 0.010 0.100000023 0.009999170 -4.605169296
2 0.020 0.141421377 0.019998097 -3.912022709
3 0.030 0.173205137 0.029995018 -3.506557941
4 0.040 0.199999988 0.039988934 -3.218876123
5 0.050 0.223606824 0.049978864 -2.995732426
6 0.060 0.244948923 0.059963786 -2.813410758
7 0.070 0.264575123 0.069942712 -2.659260034
8 0.080 0.282842695 0.079914629 -2.525728940
9 0.090 0.299999952 0.089877808 -2.407945394
10 0.100 0.316227674 0.099832785 -2.302585244
11 0.110 0.331662416 0.109777808 -2.207275629
12 0.120 0.346410095 0.119711756 -2.120264172
13 0.130 0.360554993 0.129633784 -2.040220499
14 0.140 0.374165654 0.139542877 -1.966113448
15 0.150 0.387298226 0.149437963 -1.897120475
16 0.160 0.399999916 0.159317374 -1.832582354
17 0.170 0.412310421 0.169181585 -1.771957278
.
The result is 58secs, that means 1.16sec single loop.
Not sure we run the Fortran with "27bit precision", but based on the link above this PDP-8/A (XC6) is 18s / 1.16s =
15.5x faster than the original PDP-8/E.
Now, what is the CPU_clk then

PS: Who is using Fortran?
http://web.mit.edu/humor/Computers/real.programmers