Multiple OS in a Laptop or Desktop
The limiting factor is probably the available disk space or the number of partitions you can create.
You can have three and more OSs installed, though I am not sure that W8 is a good candidate at the moment. It might not play nicely with other bootloaders, like Grub or EasyBCD.
Performance is unrelated to the number of OSs installed.
If you want to use the OSes in parallel, you might consider installing only one OS directly (e.g., Ubuntu/Linux) and then run the other OSes inside a virtual machine such as VirtualBox or VMware Workstation.
Virtual Machines allow you to run multiple OSes in parallel without the need of partitioning the disk accordingly. They even allow you to share folders between virtual machines (e.g., have a Linux directory available in your virtual Windows installation). They suffer from lower performance, though. So if you want to use Windows for gaming, it might be worthwile having a native Windows installation and running Linux inside a virtual machine instead.