Hi,
I have the same problem as this. But for me the blackout happens more often, at least 2x every 30 seconds and at any resolution. My Dell S2440L is brand new, less than a month old and my GFX card was bought at the same time, it is an Asus GTX 750 Ti. My rig specs are:
I tried the test you gave and the Dell S2440L passed them. Are there known compatibility issues? Btw, the mobo board is an Asus P8Z77-M Pro and the Nvidia web drivers are the latest just downloaded them last week. Hope you can shed some light on this.