Reading CSV files in R: read.csv vs read_csv

set
  i /a1*a100/
  j /b1*b100/
  k /c1*c100/
  l /d1*d100/
;

parameter d(i,j,k,l);
d(i,j,k,l) = uniform(0,1);

$setenv gdxcompress 1
execute_unload"d.gdx",d;
execute"gdxdump d.gdx output=d.csv symb=d delim=comma format=csv";

D:\tmp\csv>head d.csv
"i","j","k","l","Val"
"a1","b1","c1","d1",0.171747132
"a1","b1","c1","d2",0.843266708
"a1","b1","c1","d3",0.550375356
"a1","b1","c1","d4",0.301137904
"a1","b1","c1","d5",0.292212117
"a1","b1","c1","d6",0.224052867
"a1","b1","c1","d7",0.349830504
"a1","b1","c1","d8",0.856270347
"a1","b1","c1","d9",0.067113723

D:\tmp\csv>dir d.*
Volume in drive D is My Passport
Volume Serial Number is 74B7-6DCC

Directory of D:\tmp\csv

12/08/2016  03:42 PM     3,656,869,678 d.csv
12/08/2016  03:30 PM       806,199,476 d.gdx
               2 File(s)  4,463,069,154 bytes
               0 Dir(s)  1,099,214,491,648 bytes free

D:\tmp\csv>

> system.time(d<-read.csv("d.csv"))
   user  system elapsed 
1361.61   50.56 1434.39

> system.time(d<-read_csv("d2.csv.gz"))
Error in .Call("readr_read_connection_", PACKAGE = "readr", con, chunk_size) : 
  negative length vectors are not allowed
Timing stopped at: 57.53 4.43 62.29 

t0=pc()
df=pd.read_csv("d.csv")
print(pc()-t0)

158.2270488541103