Charge your phone to a 100%, and download Better Battery Stats. Then use your phone with moderate settings, as you would normally. When it reaches 1-2%, check the screen time, and keep a record of how much was consumed by what. Then turn on Best WiFi performance, charge to full, and try this again. You should notice a difference according to the OP.
Sent from my HTC One X using Android Central Forums
I don't think he was wining, just adding more confirmation. Yes, it is a simple solution IF YOU KNEW that was what was causing the problem. And there in is the major problem. Many people turn that setting on, shortly after getting the phone, and don't even know their crappy battery life is abnormal. Others turn it on with many other settings and loading of lots of apps and then have to figure out what happened. It is a stupid setting with nowhere near enough warning to the user.
I appreciate that I am bumping an old thread, but I would like to relate my experience which is directly relevant to the OP's original comments.
I picked up an HTC One a month ago and then on Saturday set up a brand new router. Being a tinkerer, I was fiddling with this and that on the router trying to optimize everything. I also played with the phone and amongst various settings I decided to turn on "best wifi performance". The One has the warning about "may consume more power", but I did not think much about it as I knew I had very good battery life and believed that a bit more power would probably not change matters that much.
Come yesterday evening and my battery life was horrendous and I started scratching my head as to why it had gone to hell in a hand basket. Finally, I recalled that I had adjusted "best wifi performance" and did a search on this. The OP's post came up at the top or near the top (HTC One in a google search also includes HTC One X
I turned it off, recharged my phone and followed battery life keenly. It is far better today. Without a hint of an exaggeration, having "best wifi performance" on cut my battery life by 1/2 to 2/3 (just like the OP's experience).