nginx 1.2.0 is slower than 1.1.12?

[Delta Yeh]

Hi,

   I did a simple load test  for 1.2 and found that 1.2 is slower than 1.1.12 ?

  client---nginx(1.2/.1.12)----nginx(1.1.12)
   The tested nginx worked as a reverse proxy before another nginx box
 which serve static file,  upstream keepalive is not enbaled.

    Same test suite , the only difference is the version of nginx.
1.2.0 is about 30% slower .

BR,
DeltaY