Hi, I have a 2008ish Macbook Pro, and I have resisted from upgrading OS since Snow Leopard, as my Logic Pro 8 suit isn't compatible from Lion upwards. It occurred to me I could install Mavericks on my primary internal HDD, and install Snow Leopard on a spare external USB HDD I have at home, purely to install Logic Pro 8 on. My Macbook Pro has USB 2.0 ports. Would I experience significant performance reduction loading the OS and running Logic from an USB powered external HDD vs my internal SATA HDD? I know I could also install on a separate partition, but as I said, I don't use the Logic software frequently, and would prefer to save HDD space on my primary HDD.