Move OSX to external drive

[Thomas Smet]

I love my new Imac for FCS but it really kills me that FW800 is the best solution for video storage. I recently read about people using external drives to load OSX and I thought this may actually be a decent option.

Here is what I am thinking of doing. Move my boot drive to an external drive. I can live with a slightly slower boot time. I can then turn my internal 7200 SATA drive into my edit drive. Currently FW800 is a bottleneck since it can't seem to go higher then around 80MB/S. I just did an AJA speed test of my internal drive with OSX with everything else currently on it and it seems to be a steady 120MB/S. That seems like a pretty big boost. Now I know a single drive can slow down as it gets full but honestly I don't really plan on working with that much video at the same time. I tend to use my media drive for my current project and backup projects I'm not working on to other external devices. When I need to work on another project I move the media back to my media drive.

Anyway am I nuts in thinking that this may be a good solution?

[Nigel Barker]

It all depends whether the disk performance of your external FW800 drive is really hindering you at present. I doubt that it is & think that you will find the serious inconvenience of your proposed solution will outweigh any possible benefit.

[Robert Lane]

I see where you're going with this theory but actually you'd be hurting performance rather than helping it by making your OS drive external. Remember that all your apps and the OS itself requires a ton of back-and-forth communication to the mainboard bus for round-tripping to the CPU, RAM and FSB cache. If you take your OS externally now you're forcing all that communication down to a single pipe whereas with the internal SATA drive the OS can choose which lane on the FSB it wan't to move it's data.

You're best off making your media and cache drive external on a fast 7200rpm FW800 drive. Take a look at the offerings from OWC (Performance Upgrades; FireWire USB SATA Storage; Memory, more at OWC)

Also, if you're ever in question about what method to use for taking your system to the next level you can use this post as a rough guide:

Grumpy Quail: Setting up your Computer for HD Video Editing

[Thomas Smet]

Hey thanks for the feedback. I kind of had some suspicions that may be the case with an external OS drive. Thats why I came here to ask. I was a PC user with Avid for years and just recently moved to FCS. So far I have been very happy. I bought a base model Imac just to see if it was the direction I really wanted to move. I think next year I may move to a Mac Pro anyway so I may just deal with the external media drive for now. To be honest I have actually had decent Prores results even from an external USB2 drive so I think I would be more then fine with FW800.

One other question. How about doing a partition of my internal drive. That way I can keep 100GB or so for the OS and dedicate the rest to Media. This should give me the best of both worlds I guess. I will look into an external FW800 solution however.

One thing I did notice is that performance wise a 2 drive external FW800 raid doesn't seem to really perform all that much faster then a single FW800 drive. Assuming 3.5" 7200 drives of course. I realize the case may be different for 2.5" drives or 5400 rpm drives.

Thanks again for the guidance. I used to be a forum moderator for Avid and it has been a little frustrating at times not being an expert anymore due to a total system change.

[Arnie Schlissel]

It's a bad idea to partition your internal drive like this. You will still be using the same hardware device for both booting and media, but now the heads will be working overtime shuttling back & forth between partitions.

[Vic Owen]

"One other question. How about doing a partition of my internal drive. That way I can keep 100GB or so for the OS and dedicate the rest to Media. This should give me the best of both worlds I guess. I will look into an external FW800 solution however."

This is not recommended. The demands on the boot drive are fairly intensive, and asking it to keep up with media access, as well as housekeeping chores, will cause you lots of problems. Keep ALL media on a separate internal or external drive, dedicated for that purpose, only. Your computer will like you...

[Thomas Smet]

Alright that settles it then. I guess a lot of the same rules do apply on the Mac. Thanks for confirming all of this for me. It has been very helpful so far. Now I just need to figure out if I want a FW800 raid or if a single drive will be fine. All the reviews I have seen of modern 7200 rpm drives indicate that when full a good drive may only slow down to about 75 MB/S or about what FW800 will give me anyway.

[Carl Rubin]

Get a copy of XBench and do some performance comparisons between internal and external drives. You'll be surprised. For example, a MBP 5400 rpm internal drive is slower than a FW800 7200 rpm G-Drive.

[Shaun Roemich]

For what it's worth, I reliably pull Apple ProRes media at 1GB/minute off a FW400 connected hard drive that is 8 years old. Unless you are using VERY high bitrate media compression (uncompressed HD for example) or MULTIPLE streams of high bitrate material, you are unlikely to have a bottle neck with a FW800 connected external.