You are thinking of the ethlargment pill. It's generally not needed any more as Phoenix miner/ claymore*/ T-rex and others have memory tweaks/ timing built in via command line. It is -straps for Phoenix and --mt for T-rex. Take a look at the readme files for the miners. I am getting 45 MH @ 165 watts with 120 OC and -1000 (linux, -500 win). I could get higher with more power but that seems like a good balance for watts to MH. Claymore isn't supported anymore by the dev so I wouldn't recommend it.
I stop mining actually for very long time due to Electricity rate so I don't have idea about straps. But I heard there are still some people use ethlargementpill and I remember that latest driver would not work the last time that I mine but downgrading the driver will work.
ETHthlargment pill
What OS do you mine? At HiveOS then you are creating flight sheet - there is a button to power on this pill. At win - you need to edit bat file.
Planning to use the Windows OS again since this is what I use when I start mining before.
Did you get around 50mh/s on HiveOS?