BUT I DIDN'T GET RPLY THERE WITHIN 2 DAYS SO I POST THE SAME QUESTION HERE.AND THE FIRST ONE IS NOT RELATED TO THIS QUESTION.AND THANX FOR ALL YOUR RESPONSE.
Then If I may on behalf of the active members answering and helping allot on the forums, please restrict the question to one thread as is is difficult enough tracking member questions across the forums without having to answer the same person three time for the same question and if we ignore the other two it looks bad on the community as it seems to others were not helping
If you really must do this then simply link from that forum to the primary question and state it is a duplicate from another thread... ie help us to be more eficient
As Mark said the great majority of Arduinos in use use the AtMega 328 chip there's very little extra hardware on an Arduino and if you put the boot loader on the chip the performance will be the same.
However over the years there has been a proliferation of variations of Arduino designs most been similar to above but others like the Arduino Mega or Leonardo for example use the AtMega 2560 and At32u4 CPUs respectively with differing specs to the '328 CPU.
Further more the latest Arduinos are based on totally different Architectures such as the cortex M3 based Atmel SAM3X8E on the Arduino Due http://arduino.cc/en/Main/arduinoBoardDue
Basically yes they are the same, but remember the fringe cases where some one has done something different
