Cheap GTX 1080ti How does it perform (inno3d Gtx 1080ti x2) Firestrike

The cheapest Gtx 1080ti i could find at £620 how does it perform, there will be a series of benchmarks. System Specs are 6700k @4.7ghz 16gb viper 2800mhz ram asus z170 pro gaming motherboard 256gb nvme ssd