BIOS updates are being recalled and replaced. Woody Leonhard has the scoop on several vendors.
My new rig had a second BIOS update 2 days ago. Previous BIOS version was F5i. It has disappeared and been replaced by F5m. Yesterday I reran PCMark10 on that rig. Performance drooped again. On PCMark10 I now have a performance loss of 6.4% overall, with a high of 9.9% in Essentials. Post updated here: Meltdown & Spectre Updates Benchmarked