

   ͻ
                                                                            
                  INTEL MATH COPROCESSOR TECHNICAL INFORMATION              
                                                                            
   ͼ





   387(TM) DX AND WEITEK SOCKETS
   

       Many computers contain with a square socket for a Weitek math
       coprocessor.  This  socket has three rows of holes on all four sides.
       In many computers, such as the Compaq 386, the inner two rows of pins
       are compatible with the Intel 387DX.  This  gives you the option of
       using an 387DX or the Weitek math coprocessor.

       However, if you want to install an 387DX in the Weitek socket, you must
       use EXTREME CAUTION to orient the chip correctly; otherwise you could
       damage the computer and the 387DX.  Read your computer's User Guide to
       determine the correct procedure for installing the 387DX in your
       computer.  The Installation Guide for the 387DX contains general
       information which may be useful also.  If you have trouble figuring out
       how to correctly install the chip, have your dealer perform the
       installation for you.  Intel can't replace a part which has been
       destroyed by incorrect installation.

       Some computers use the Weitek socket but DO NOT support the 387DX, such
       as the TANDY 4000.  Contact your computer manufacturer or dealer for
       more specific information.


   SPEED TESTS
   

       The following table lists the results of tests Intel performed in an
       IBM PC AT.  The first two columns compare computation times for the
       standard IBM PC AT with and without an Intel Math Coprocessor.  The
       third and fourth columns depict the same IBM AT upgraded with the Intel
       Inboard 386.  The third column lists results obtained using the 80287
       Math Module with the 386DX while the fourth column shows the
       386DX/387DX combination.















   

   2/90                        Intel FaxBack # 3010                     Page 1




   ͻ
                                                                            
                  INTEL MATH COPROCESSOR TECHNICAL INFORMATION              
                                                                            
   (continued)ͼ



      Ŀ
       SYSTEMS: IBM PC AT    IBM PC AT   Inboard 386  Inboard 386
                 without      with         with         with     
               Coprocessor  Coprocessor  Math Module    387DX    
      ͵
       WHETSTONES    -----     102K         183K         319K    
      Ĵ
       LOTUS 123 (time in seconds):                              
        Budget        8.3       8.3          3.7          3.7    
        Finance      13.5       5.7          2.7          2.2    
        Engineering  29.2       3.9          1.9          1.5    
      Ĵ
       AUTOCAD:                                                  
        Regen        53.0      12.0         9.4          8.1     
        Remove                                                   
         Hidden      16:14     8:01         6:58         6:19    
         Lines                                                   
      


   GENERAL SOFTWARE USE OF MATH COPROCESSORS
   

       Not all programs make good use of Math Coprocessors. Scientific and
       CAD/Graphics programs use math coprocessors extensively for screen
       graphics and floating point calculations. Spreadsheets use coprocessors
       for exponents, internal rate of return, net present value, and certain
       arithmetic calculations. A math coprocessor won't speed up addition and
       subtraction and will speed up multiplication and division only
       slightly.


   REPLACEMENT 8088
   

       If you have an 8087 and a 4.77-MHz 8088 dated '78, you can get a free
       replacement 8088.  Contact Intel Customer Support for the replacement.

       NOTE:  Only 4.77-MHz 8088 chips need to upgraded.  The 8088-2 and 8088-
              1 do not require replacement.











   

   2/90                        Intel FaxBack # 3010                     Page 2




   ͻ
                                                                            
                  INTEL MATH COPROCESSOR TECHNICAL INFORMATION              
                                                                            
   (continued)ͼ



   MATH COPROCESSOR POWER CONSUMPTION
   

       The Intel Math CoProcessors consume the following amounts of power.

      Ŀ
         Chip      Power   
      ͵
       8087      3 watts   
       80287     3 watts   
       80C287A   1.5 watts 
       387DX     1.5 watts 
      

       These are worst case figures; typical power consumption is somewhat
       less.



































   

   2/90                        Intel FaxBack # 3010                     Page 3


