Don't take my word for granted, but the OC on core clock is huge are you sure your cooler can work under such loads? Can you post an image of you MSI afterburner specs while under load?
What model is that xt ??
Those cards run notoriously hot & unless its the twin fan sapphire the coolers aren't good enough for that core clock , it'll 100% be throttling .
1050 core is the most I've seen on a single fan model