Can I use a modern GPU with an LGA 1155 motherboard?
You can, but with modern GPUs coming with PCI-E 4.0 and higher support, you might find performance lacking. PCI-E is fully backward compatible, meaning a 4.0 or 5.0 device an work in a 3.0 slot. However, it will only use the full bandwidth for the 3.0 standard.