"I don't know much about the scratch disk with a virtual machine. What I do know is that it's usefull to have an external drive on which your media is. This way you have 2 drives, which will increase speed. Cause one is for when your RAM is full, and the other for your files (scratch disk)."
I hope you don't mind me asking all these dumb questions but what you are telling me above is important and I could use some clarification please... 😕
1) When you say "media" are you referring to the actual program (which is Premiere Pro for Windows in this case)? And if so, does that mean that you install the actual program on the external hard drive?
2) What do you mean when you say that "one (hard drive) is for when your RAM is full"?
Thanks again.
Steve
Scratch Disk: The amount of video data, applications need to handle, can not be simply put into RAM. In full HD quality they might go into TBs of data. Editing application will but the temporary ("scratch") data on the disk while rendering effects, cuts, etc. In a usual editing environment you will have very fast RAID sets or at least, in smaller scale, dedicated disks for the editing application to use. Since there is a lot of disk access necessary while huge amounts of data is shuffled between RAM and HD, mostly, the scratch disks are used solely for this temporary data. Source material and final products, applications, the OS, etc are running from separate disks.
Of course it is possible to to run everything of one disk, like it is often the case on laptops for example. But performance will suffer immensely and it is only advisable for rough pre-editing on the road, or, if you will, making a home movie. Since Apple laptops provide (these days "provided"
🙁 ) firewire ports the situation could be helped to some extend. USB is feasible but less so since it is not a streaming protocol.
Virtual Machine (VM): In a VM everything the OS sees, in your case Windows, is abstracted by the application (Fusion, Parallels, etc). Inherently, Windows "thinks" it is running on a standard PC. Nevertheless, almost every call to the system as in writing/ reading data to/ from the disk image, drawing a picture on your screen via the graphic card, etc travels through this extra layer of virtualization. Besides this your host OS, OSX, is also running, requesting disk, CPU, GPU, RAM access, etc. Especially for the guest OS, huge bottle necks on all fronts are a certain reality, and unforgivable for high performance computing as video editing is. Another example, real-time previews of effects, are impossible in such an environment since there is no direct access to GPU features.
Software VM, as Fusion and Parallels, are certainly useful for a large range of appliances and have become quite usable. These days even older 3D games will perform admirably on it but don't confuse this with video editing, scientific computing, and akin. It is still a limited solution to run several OSes at one time and add benefit to your computing experiences if you need such.
Boot Camp: This is not a virtualization. Boot Camp will create a partition on the hard disk for use with another OS and provide an EFI hook to simulate a BIOS (Macs don't have a BIOS they use the more advanced EFI standard) upon which Windows is able to boot on a Mac. Additionally, Apple provides Windows drivers for the Mac hardware. Unlike in a VM solution, only one OS can run at the time. To switch, one must restart the computer into the other OS. However, nothing is virtualised (arguably the BIOS but can be neglected) and Windows us running as it would run on a PC with direct access to all the hardware and performance available.
I hope that helps.
