Spiking GPU usage while playing Minecraft?

I'm concerned about my videocard because my previous videocards died from Minecraft. First videocard overheated (but only fan was damaged), second videocard was runing nice after playing Minecraft, but next morning i get black screen when turning on computer. Why Minecraft damaged my previous videocards? And why now i'm getting spiking GPU usage while playing Minecraft, one second it's 70% and then other second 0% and so on. I'm Really concerned about that, but i also want to play Minecraft, because it's kinda creative game. My biggest worry is that i will burn my new videocard that cost me 130 Dollars.

My GPU-Z screen:

My specs:
Pentium(R) Dual-Core E6500 2.93 GHz
RAM: 3.00 GB
Windows 7
AMD Radeon HD 7770 1GB

My Previous videocards:
Nvidia GeForce 8600GT 512MB
Nvidia GeForce 9800GT 1GB (I'm not if it was 1GB or 512MB)

Added (1). My previous videocards didn't have issues with other games, only with Minecraft.
And only Minecraft gives me spiking GPU usage, other games work fine and GPU usage is steady.

Added (2). raina_vissora… It only happened after/when playing Minecraft. (for old videocards)
And same for new videocard… I only get spiking GPU load when playing ONLY Minecraft. Other games work fine and GPU load is steady.

FORinfo

Er… Have you ever considered that maybe you've got a short on your board somewhere that's killing your graphics cards? Running a game might accelerate the problem, but odds are it's something hardware related that's actually killing it.

raina_vissora

It's all good, as long as your gpu temp doesn't go above 80 degrees

Matthew

I doubt your graphics cards were actually damaged, but try investing in something more substantial, like a http://www.newegg.com/...6814130838. That GPU is pretty good to start out with, you shouldn't be worried about your graphics card being damaged. I don't think that your previous graphics cards were damaged, since it would shut down automatically due to heat, without it damaging parts (most parts have a thermal sensor that will shut them down). I would say continue chopping trees, and grief on. Don't worry about your graphics card.

Lafar