Hardware Review: the NEC V20 Processor

by Adrian Smith

Transcribed from the printed issue; not yet reviewed. Read it in the PDF of the issue, page 51

Background¶

The NEC V20 is a straight swop for the standard 8086 CPU chip that comes with your PC. It costs around £18.00, and is claimed to speed up applications by an average of 10%. In particular it improves screen-access times, and anything involving graphics should go up to 50% faster.

Having shelled out my £18 to the imaginatively titled Ctrl-Alt-Deli (waits apprehensively for the machine to re-boot!!) I fired off my usual set of APL benchmarks. One side issue to note is the drop in speed on using APL-V.6 as opposed to APL-V.5 ... for interest I also timed some simple array operations on both versions; you may draw your own conclusions!

Benchmark Results¶

Firstly my standard collection from VECTOR 4.1. As previously noted, the simple 1000 looper FN 1000 seems to be the best indicator of overall speed:

APL Expression                Type        Vn.6     Vn.5     V20(5)
--------------                ----        ----     ----     ------
T←⎕TS ⋄ +/V+V   ⋄ DO ⎕TS-T ⍝ INT ....      390      380      350
T←⎕TS ⋄ +/V[I]  ⋄ DO ⎕TS-T ⍝ INT ....       60       60       50
------------------------------------------------------------------
T←⎕TS ⋄ V+.×V   ⋄ DO ⎕TS-T ⍝ RL  ....      490      440      380
T←⎕TS ⋄ +/V*2   ⋄ DO ⎕TS-T ⍝ RL  ....     4220     4120     3680
T←⎕TS ⋄ X←+/M   ⋄ DO ⎕TS-T ⍝ RL  ....      710      720      660
T←⎕TS ⋄ V+.×,M  ⋄ DO ⎕TS-T ⍝ RL  ....     2360     2360     2140
------------------------------------------------------------------
T←⎕TS ⋄ +/S='T'    ⋄ DO ⎕TS-T ⍝ CH ...    4010     3790     3630
T←⎕TS ⋄ 'FAT'⍷S    ⋄ DO ⎕TS-T ⍝ CH ...      60       60       60
T←⎕TS ⋄ X←S∊'FAT'  ⋄ DO ⎕TS-T ⍝ CH ...    5710     2860     2520
------------------------------------------------------------------
T←⎕TS ⋄ X←B∨B∧~B ⋄ DO ⎕TS-T ⍝ BL....      5710     4950     4840
T←⎕TS ⋄ ∧/B      ⋄ DO ⎕TS-T ⍝ BL....       160      140      110
T←⎕TS ⋄ X←∨\B    ⋄ DO ⎕TS-T ⍝ BL....       320      280      220
------------------------------------------------------------------
T←⎕TS ⋄ FN 10    ⋄ DO ⎕TS-T ⍝ FN....       550      390      330
T←⎕TS ⋄ FN 100   ⋄ DO ⎕TS-T ⍝ FN....      4080     3300     3100
T←⎕TS ⋄ FN 1000  ⋄ DO ⎕TS-T ⍝ FN....     47.7s    34.6s    30.3s
==================================================================

... and then the timimgs for some simple array operations to illustrate the precipice at the 32K boundary:

+/S×'T'

   ⍴S      V.5      V.6
   --      ---      ---
  1000     380      440
  2000     770      820
  5000    1920     1970
 10000    3790     4010
 20000    7630     7910
 30000   11370    11860
 40000     ---     22.9s
 50000     ---     27.4s
 60000     ---     34.4s
100000     ---     WS FULL
                   IN 195K

+/V+V

   ⍴V      V.5      V.6
   --      ---      ---
  1000     380      440
  2000     730      770
  5000    5170     1920
 10000    9610     9670
 15000   19270    18460
 20000   11370    11860
 25000   24500    22900
 30000   28800    27400
 40000     ---    45900

⎕WA 300K APPROX

Conclusion¶

The V-20 is good value for money in price-performance terms when compared with any of the other 'go-faster' boards, all of which come in well above £500. I could claim to see the difference in ⎕WPUT and graphics tests, but the improvement is otherwise too marginal to show up in day to day use.

NEC V20 is available from:

Ctrl-Alt-Deli, 44 Brownbaker Court, Milton Keynes.
Cost: £20 approx.