Building A PC for Video Editing
Dennis writes, "Do you have any suggestions regarding what motherboards would be best for speed while doing home movie processing and live streaming of video. I get discouraged while doing my home movie editing while waiting for Pinnacle Studio to render a one hour video, only to find out that I made some errors during editing and then have to wait while rendering again to see if I fixed the problems. I am intending to build a new computer specifically for video editing. Could you recommend any web sites that test motherboards specifically for video editing? Am I using the wrong (slow) software?"
Rendering video of any size takes time. It's one of the most resource intensive operations we do with our computers. Beyond hardware bottlenecks, the rendering time is greatly increased when complex transitions and effects are added to videos. Putting titles over your video image adds a layer of complexity. Even adding multiple audio tracks, like layering a soundtrack under the original movie audio increases the amount of time it takes to render a video. The best way to reduce rendering time is to apply the Alfred Hitchcock school of filmmaking to every project, which is to record as much of your footage as possible without needing transitions and when transitions are required, make them simple cuts not a wipe or dissolve. While keeping the image complexity to a minimum will help reduce rendering time, it's also true that there are performance gains to be had from optimizing hardware.
Four key areas offer the biggest hardware performance boosts for video rendering. These are the main areas where the system has bottlenecks in communicating the video processing information. The amount of memory your system has is one potential bottleneck. Processor speed and processor bus speed both play a role in determining how effectively your computer can crunch all that video information. The third area where you may see a small performance boost is in the speed of your hard disk. The fourth potential area of improvement is dedicated GPU memory.
How much memory (RAM) your computer has, whether it's a Mac or PC, makes a huge difference in how quickly your computer can render video because it plays a role in determining how much video information the computer can work with at any given time before it has to swap the information out for the next chunk of data. Without making any upgrades, you can improve your performance in this area by turning off excess programs. Close browser windows, shut down your anti-virus (yes, this is safe while you aren't doing anything that might result in infection) and exit your email app. These are three of the biggest memory hogs in computing. Max out your systems available memory, whether that's 1GB, 2GB or 3GB. Purchasing a computer with a 64-bit processor makes it easy to dramatically increase the max RAM your system supports. You can easily get by with less memory, but if you want a noticeable performance increase, you need to invest in serious hardware upgrades.
Processor speed and processor bus speed play a significant role in video rendering. Ideally, having a multi-core system and/or a 64-bit processor is required to make significant performance jumps when processing video. Even if your video editing software isn't optimized for a 64-bit processor, I've found dramatic speed increases rendering the same video on a 64-bit processor machine when compared to performance on an otherwise comparable 32-bit system. Also make sure you look at getting the processor with the fastest front side bus speed you can afford. You may find a great deal on a seemingly fast machine, but make sure the bus speed is the top end version and not hobbled. Bus speed determines how quickly information is fed in and out of the processor, which is a choke point when dealing with complex operations like video processing.
Hard drive speeds and drive seek times are both important but only marginally change the speed of rendering. Look at SATA drives here, with 10,000 RPM speeds and seek times in the 5-6ms range. Data transfer speeds are also important factors to consider, but most SATA drives are fairly comparable in transfer speed. If you are picking one of these four areas to not upgrade for budgetary reasons, this would be the one you could skimp on from a rendering perspective.
The fourth area to consider is your system's GPU. This only comes into play for video editing software with support for addressing the GPU directly, but makes a huge difference when available. I recommend anyone working with HD video should invest in a GPU with a minimum of 512MB of dedicated video RAM. This allows your computer to offload intensive video rendering directly to the video card, saving your CPU for other operations.
Ultimately, you're only shaving minutes off the rendering time in maxing out your system. While upgrading from an old P3 system to something built in 2008 will offer dramatic performance enhancements across the board, maxing out hardware of a current computer will only add marginal benefits over the cheaper version. Video rendering takes a ton of resources and tends to use as many resources as are available. Even in a fully optimized system, plan to wait approximately 1 minute of rendering time for every minute of video footage. Faster render times are possible, however, if you invest a bunch of time in editing, you likely want the best looking result possible and quality takes more time. When I render video for my own projects, I tend to start the process at a time when I can go do something else, like sleep or work on a different computer, so I avoid waiting around for the job to finish.