Maintaining a Stable Computer System for Video Editing

 

Introduction

One of the more common peices of advice you get for maintaining a good Non-Linear Editing system is to dedicate the computer to just video editing: no Office, no games, no internet: just video editing software and hardware only.  This isn't bad advice, and if you're a business relying on it to pay the bills, then you should have two or more dedicated systems so that when one goes down (not if one goes down, but when), your clients aren't left hanging for two  months while you try to sort through the finger pointing to find out what is really broken and get it fixed.  For the rest of us mere mortals though, we can afford only one computer system and we're the only ones left hanging if there is a problem because it's just a hobby.  This essay is for us.  

I originally wrote this essay about three years ago now.  Computer technology has gone through two full iterations of Moore's law since then, so I felt that some of the advice was sorely in need of updating to reflect more current machines.  I've therefore rewritten large portions of this essay, although I will refer back to the older advice to give some historical perspective.

Disk Subsystem

While we may have only one computer to use for everything and can't afford to have a second computer to dedicate to video editing, it is absolutely necessary to dedicate a disk drive to video editing.  The absolutely last thing you want to happen while you are capturing or playing back video is for something else to also want to read or write from the same physical disk at the same time.  With today's fast interfaces and fast disk drives, you can get by with a little bit of I/O happening to a different physical disk, but the latency of moving the heads back and forwards will kill your throughput if you get I/O to the same physical disk..

Now, on you're non-video disk or disks, there are at least three sets of things you want to keep isolated from each other: the OS and application installation, documents, and temp files (including the swap file).  These should be in separate partitions.  With 80GB disk drives being only $205 now mail order, I'm going to assume that is what we are working with for a system disk.  I recommend partitioning it 8-16-54.  Note that Microsoft's fdisk has a bug in dealing with physical disks bigger than 64GB.   They have an update to fix this.  Search for Knowledge Base article Q263044.   However, this one doesn't work on disks bigger than 128GB.  More on this below.

The boot partition on the system disk should be just under 8GB and be reserved for installing the OS and applications.  I'm assuming the use of Win98SE and FAT32 here.   WinME is just too buggy and it seems device manufacturers still come out with Win98 drivers first, and WinNT drivers in beta much later, if ever.  I used to recommend installling applications on a separate partition from the OS.  The huge size of current disks makes creating a full image of the boot partition for backup purposes very easy.  It is no longer necessary to keep it small to make that practical, so I no longer worry about an application installation trashing my boot partition.  I do recommend keeping the boot partition size just under 8GB.  The OS and application installations create hundreds, nay thousands, of tiny files.   FAT32 uses 4KB cluster sizes until the disk exceeds 8GB, then it witches to 8KB or larger cluster sizes.  You'll waste less space with the smaller cluster size.

Document files should be kept on a partition by themselves.  By not putting them on the same partition as OS or application installations, or on the same partition as temporary files, they are far less likely to get trashed by an installation gone bad or the OS corrupting the swap file or inconsistancies in the file system from system crashes happening with lots of temporary files open.  You can point My Documents to any directory you want by right clicking on it and selecting Properties.  Since Documents are typically a little larger I don't worry so much about cluster size on my documents partition.  I set mine at just below 16GB, which gives me 8KB clusters.

The remainder of the disk space is one huge partition that should be used for more transient files.  Set the swap file to go to this partition.  For any application, like Outlook, Internet Explorer, PhotoShop, Premiere, Media Studio Pro, etc. that let you direct their temporary files, direct the temporary files to this partition.   This is the partition that gets the brunt of the file system corruption when the system crashes.  If you are trying to get by with only a single hard drive, this is the one where you would do your video capture to as well.  Even better though would be to have a separate disk, or a RAID, for video capture and backup purposes though.

SCSI vs IDE vs RAID

Modern IDE is fast: really really fast.  Modern IDE disk drives are also huge and fast.  I used to recommend dropping IDE in favor of a pure SCSI system since SCSI was faster and allowed more devices.  Now, with 80GB disk drives being dirt cheap, I don't think the high cost of SCSI disks is justified anymore. 

Further, many motherboards come with built in RAID that uses IDE disks.  My new system has an 80GB drive for my system disk on the regular IDE controller, and two 80GB disks on the builtin RAID controller.  If you are desparate for IRQ's, RAID controllers can be booted from and occupy only a single IRQ, so you may be able to recover IRQ 14 and 15 by just using the RAID controller.  Beware when building a RAID partition bigger than 128MB that the fixed version of fdisk mentioned above does not work.   You can use the original version of fdisk and specify 100%: just ignore everything it says about 21GB partition being created!  Unfortunately, this sets the cluster size to 32KB.  For my 160GB RAID, scandisk and defrag won't work unless the cluster size is 128KB for that size disk.  Nortan's scandisk seems to work OK, and you may be able to use the lastest version of Partition Magic to correct the cluster size.  They claim to have fixed the >64GB problems they had before, but I've not upgraded yet, so I haven't verified that it works OK.

FAT 32

Don't be scared by the newness of FAT32 or reports of it being slower (OK, so its not so new anymore; still, the advice is good).  With modern disk drives, you have to have it in order to access the whole drive.  FAT16 can only be 2GB in size and must be in the lower 8GB of a drive.  If you want to use the newer gigantic drives, you have to use FAT32.  These new drives are so much faster than drives of only a few months ago (viva Moore's law!), there is simply no reason to worry about a couple of percent performance loss from FAT32. 

Compressed Volumes

With the huge size of modern disks, and the fact that compressed volumes require FAT16 host file systems, I no longer recommend installing your applications on a compressed file system.

Backups

The number one important thing to do to maintain a stable system is to keep backups.   I used to recommend keeping the boot partition small, with no applications installed on it, to make backing it up to CD-R easy.  I've modified that advice now to keep OS and applications on a single 8GB partition, which makes backing up to CD-R inconvenient.  What I recommend doing now is using a full partition imaging program, such as Ghost, to make an image of the boot partition on a separate physical disk.   Putting it on a different partition of the same physical disk is fine as a safety measure before installing a bunch of software, but for safety from the death of a physical disk, you really need to put it on a different one.  I keep a couple of recent images on my RAID array.  With the speed of these things, it only takes a few minutes, compared to a few hours to burn that many CD-R disks.

I still prefer burning backups of my documents on to CD-R.  This makes them more easily accessed from multiple computers.  I'm still looking for decent software to automate this process.  Backup Exec has the problem that it doesn't use the standard file system, so you need Backup Exec installed on any computer you want to recover files from.  Worse, it won't read its own format on anything but a CD-R drive -- it won't read its backups on a regular CD-ROM, which makes it extra inconvenient.

Backing up multimedia files is pretty much hopeless.  They are just too large.   I suppose with the DVD-R,-RW,-RAM,+RW formats becoming more affordable, it may soon be practical to make backups of the source files of small sized projects, but a backup of 100GB of video files would still take about 20 DVD's.  The only real backup of your sources are the original video tapes.

Bring your backup of your boot disk up to date before doing major installs, especially things like new versions of Internet Explorer or new drivers.  The biggest disaster I ever had was the installation of the original Internet Explorer 4.  The Active Desktop extensions back then had some nasty bugs that would completely trash your system.  If you didn't have backups, the only alternative would have been to "format c:" and start from scratch.  Fortunately, all I had to do was restore my C: partition and reinstall Real Audio(tm).  In less than an hour, my system was back up and running as though nothing ever happened.

I've seen so many postings on the net about people of feel the need to format and reinstall everything several times a year.  Well, few people have as much esoteric stuff as I do, and I have had my system trashed by IE, I've had disks go bad, I've had new drivers that didn't work, scanner drivers that thing they need to delete other drivers before they install, etc.  I've never, in six years of owning a Wintel system had to format and start over from scratch.  I did it once to do a major rearrangement of my disks and once to upgrade my motherboard.

Software

Virus Protection

There is a lot of good interesting shareware out there.  My advice is to, for the most part, just leave it out there.  Now, some of the standards, such as AC/DSee, or winzip, by all means, obtain from a reputable source and install them.  For anything else, I've had too many friends get bitten by non-malicious software that went and did destructive things because it was just not designed for their system.  Then there is the issue of viruses.   To really protect yourself, when you do download shareware, quarantine it.  Download it, save the installer away, then wait a month to see if there are any virus reports and for the virus protection software to get up to date with the viruses current when you downloaded it.  Then check it out with the virus protection software before and after installing it.

Believe it or not,  virus protection software can be a major source of instability in a system.  The problem is that a lot of these insert themselves between you and the OS so that they can monitor everything you do and run to see if a virus is involved.   Sounds like a good idea, yes, but Windows is fragile enough as it is.   Further, virus protection software like this often interferes with legitimate installation processes, causing the installer to leave the system in an inconsistant state that may only be recoverable from by using your full backup.  On more than one occasion, I've had a friend with unstable systems: frequent crashes and bizarre behaviour.   After uninstalling the virus protection software or the crash protection (which does similar interceptions of OS activities) software, and suddenly, their system was stable again.

Instead, I prefer something like Norton Utilities, which just sits in the background like a normal processes and reads all the files on  your disks looking for anything that looks like a virus.  Norton has the further benefit of some nifty tools that are usefull for disk recovery.  I don't have the most current version of Norton.  I know they have since separated out the virus checking from utilities, but I don't know what else they may have done.  Norton has had its share of bugs in the past, so cautiously make use of its features and fear and tremble when it comes upgrade time.  I've had problems with its registery backup component (its supposed to backup your registery when you install stuff, but it had a memory leak), I've seen its scan disk report false positivess, and I wouldn't trust its defrag with a ten foot pole, but its registry editor is nice, its virus scanner works the way one should, and the Norton trashcan has saved my hide a few times more than I care to think about.

Upgrades

Many major upgrades allow you to continue to have the old version installed.  When they allow this, install the new version to a new place.  This way, you don't have to uninstall or go back to backups or reinstall the old version when (not if) the new version proves to be a "downgrade".  Premiere 4.2 and 5.1 can exist at the same time.  So can MSP 2.5 and 5.x, Photoshop 4 and 5, Framemaker 5.1.1 and 5.5, etc.   You can always uninstall the old version at a later time, once you're convinced the new version is really an upgrade.

Defragging, Repartitioning, Scandisk

I don't trust defraggers, repartitioners, and scan disk programs any further than I could get into Bill Gates' mansion.  I've seen too frequently scan disk programs report errors that other ones didn't report.  Make a backup before letting any of these sorts of  programs loose on your files, especially things that try to move every block of your file like defrag programs and programs like Partition Magic.   Beware of older versions of them that don't know how to deal with physical disks bigger than 8GB especially.

CPU Hogs

A number of programs you install think they can use any amount of I/O bandwidth and CPU time whenever they feel like it.  These programs aren't particularly welcome when you are capturing video.  It important to identify these, and either permanently disable them, or remember to temporarily when you capture/playback video.  A certainly incomplete list would be (send me more via email and I may add them):

Get Microsofts wintop program and leave it running for a while.  Identify possible problem programs by noting what seems to get CPU time when you think the system should be completely idle.  In Windows98, use the System Info utility to access the System Configuration Utility to access the Startup tab to disable select programs from running at runtime (whether started from batch, ini, registry, or startup folder).  Other OS users will need to do some old fashioned detective work to track down who starts up obscure programs that sit around eating CPU time when you most need it yourself.

Reboot

Always reboot before and after major video editing sessions.  Nothing seems to make a system more unstable than doing a lot of video editing.  Starting the video editing from a clean boot maximizes the amount of time before the system goes belly up, and rebooting afterwards clears the cobwebs created by video editing so the system will be stable while you play Quake II (tm).  Another good idea (suggested to me by someone on the internet) is to do a "clean boot" before doing video editing.   This applies to Windows98 only.  Run the msconfig program, select selective startup, and clear the checkmarks beside everything.  This gets rid of all those pesky destabilizing things that run in the background, and in the end do nothing but cause mischief.  Some drivers may need some things to run anyway, so you may have to do some trial an error to determine a small list of things that you need to leave checked anyway.

DirectX6/8

Under Windows95, I could usually keep the system on for about 48 hours before it would become unstable.  When I first got Windows98, that time went down to 24 hours, but since downloading all the DirectX6 enhancements, that time has soared to over 100 hours.   Do it.  You'll be happy you did.  (People who don't have as much esoteric stuff in and attached to their systems will likely have systems that stay up much longer).   Microsoft is up to DirectX8 now, but that seems pretty stable too, and most newer video drivers seem to require it.

Conclusion

It is possible for a home system to be a relatively stable video editing platform, complete with games and Microsoft Office if you take a little bit of care as outlined above.  It doesn't come free, but it sure beats reinstalling from scratch every few months, or buying two $5000 computer systems for the home user.