1. Title: Relative CPU Performance Data 

2. Source Information
   -- Creators: Phillip Ein-Dor and Jacob Feldmesser
     -- Ein-Dor: Faculty of Management; Tel Aviv University; Ramat-Aviv; 
        Tel Aviv, 69978; Israel
   -- Donor: David W. Aha (aha@ics.uci.edu) (714) 856-8779   
   -- Date: October, 1987
 
3. Past Usage:
    1. Ein-Dor and Feldmesser (CACM 4/87, pp 308-317)
       -- Results: 
          -- linear regression prediction of relative cpu performance
          -- Recorded 34% average deviation from actual values 
    2. Kibler,D. & Aha,D. (1988).  Instance-Based Prediction of
       Real-Valued Attributes.  In Proceedings of the CSCSI (Canadian
       AI) Conference.
       -- Results:
          -- instance-based prediction of relative cpu performance
          -- similar results; no transformations required
    - Predicted attribute: cpu relative performance (numeric)

4. Relevant Information:
   -- The estimated relative performance values were estimated by the authors
      using a linear regression method.  See their article (pp 308-313) for
      more details on how the relative performance values were set.

5. Number of Instances: 209 

6. Number of Attributes: 10 (6 predictive attributes, 2 non-predictive, 
                             1 goal field, and the linear regression's guess)

7. Attribute Information:
   1. vendor name: 30 
      (adviser, amdahl,apollo, basf, bti, burroughs, c.r.d, cambex, cdc, dec, 
       dg, formation, four-phase, gould, honeywell, hp, ibm, ipl, magnuson, 
       microdata, nas, ncr, nixdorf, perkin-elmer, prime, siemens, sperry, 
       sratus, wang)
   2. Model Name: many unique symbols
   3. MYCT: machine cycle time in nanoseconds (integer)
   4. MMIN: minimum main memory in kilobytes (integer)
   5. MMAX: maximum main memory in kilobytes (integer)
   6. CACH: cache memory in kilobytes (integer)
   7. CHMIN: minimum channels in units (integer)
   8. CHMAX: maximum channels in units (integer)
   9. PRP: published relative performance (integer)
  10. ERP: estimated relative performance from the original article (integer)

8. Missing Attribute Values: None

9. Class Distribution: the class value (PRP) is continuously valued.
   PRP Value Range:   Number of Instances in Range:
   0-20               31
   21-100             121
   101-200            27
   201-300            13
   301-400            7
   401-500            4
   501-600            2
   above 600          4

Summary Statistics:
	   Min  Max   Mean    SD      PRP Correlation
   MCYT:   17   1500  203.8   260.3   -0.3071
   MMIN:   64   32000 2868.0  3878.7   0.7949
   MMAX:   64   64000 11796.1 11726.6  0.8630
   CACH:   0    256   25.2    40.6     0.6626
   CHMIN:  0    52    4.7     6.8      0.6089
   CHMAX:  0    176   18.2    26.0     0.6052
   PRP:    6    1150  105.6   160.8    1.0000
   ERP:   15    1238  99.3    154.8    0.9665

