Time frame selection can prove to be very important to the success of any strategy.
Often we want to be similar to the high frequency traders of Wall Street..... and have trades going every couple minutes.
There are many problems with trading the lower time frames, latency and broker server errors are two causes.... Keep in mind that the broker has to scramble to get the right position, if he can not find the right position for your trade he just increases the slippage.
The people trading the fast time frames are fodder for the sharks.
I have assembled some articles that people should read before deciding on working with a fast time frame. It may save you a lot of heartbreak.
http://www.theforexguy.com/forex-daily-time-frame-busting-myths/
http://www.myfxbook.com/community/experienced-traders/we-just-plain-scared-trade/298964,1
http://www.moneyshow.com/articles.asp?aid=currency-28082
http://www.forexcrunch.com/trade-responsibly-chapter-3-use-higher-time-frames/
One advantage of the higher time frames is the amount of data that you need. far less..... meaning. faster processing time.
It may be worthwhile for you to digest what is in these articles and then plan your approach to an automated system.
Have fun.!!
My 'secret' goal is to push EA Studio until I can net 3000 pips per day....