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Anatomy of a Video Editing Computer

When it comes to configuring your capture and editing station, it all starts with the processor.  Simply stated, no other system component comes close to impacting performance as much, though the direction varies by program. 

To test this, we used two computers, a Hewlett Packard xw4100 workstation running a 2.4 GHz Pentium 4 and a Dell Precision 650 workstation with dual 3.06 GHz Xeons.  Both computers were running Windows XP Professional, the HP with 2 GB of RAM, the Dell with 1 GB.  To test performance with and without hyper-threading, we ran tests with this disabled and enabled in the HP workstation while toggling the second processor in the Dell 650 on and off for our single and Dual Xeon tests.  The results are shown in Table 1.

All prosumer programs except for Sony Vegas showed significantly faster performance due to HT and/or dual processors, though results varied significantly by program.  For most prosumer editors, especially Premiere, it’s difficult to imagine that a dual processor system couldn’t pay for itself in a matter of weeks, if not days.

Sony Vegas is a special case.  We discussed our results with Sony, who informed us that when HT and multiple processors were present, they split the available threads evenly between audio and video processing.  Since our tests focused heavily on video effects, with only simple audio mixing, multiple threads provided only minimal improvement with HT enabled or dual processors running.  An HT or dual processor computer may make sense if your productions involve lots of audio processing, or if you plan to multitask with Vegas running in the background, but neither will dramatically speed video-only processing. 

Table 1: Performance by processor (DNT means did not test)

RAM Tests

Next up is RAM.  Here we tested with two programs, MediaStudio Pro and Pinnacle Studio, encoding the same test files used for the processor tests on a TK (Jonathan has this information) GHz Pentium 4 computer with increasing configurations of RAM, starting at a very low 128 MB.  As you can see in Table 2, the performance difference between 128 MB and 1 GB is very minimal, which was a surprising result, since glimpses at the Windows Performance Monitor revealed that MediaStudio Pro was using 206 MB of RAM during encoding, while Studio was using 293 MB.

When insufficient RAM exists, the computer pages back and forth to disk, which we anticipated would produce much longer rendering times.  However, with a fast, defragged disk with plenty of empty disk space, paging back and forth did not significantly slow the process.  Expect greater delays if you’re running an older computer with low RAM configurations and slower disks and less free space.

Table 2:  Rendering performance at multiple levels of RAM.

Disk Drives

To produce digital video, you’ll need capacious capacity, but do high RPM SCSI drives make a difference?  This depends upon the type of projects that you create.  In our first test, we rendered a 36 minute project in Ulead MediaStudio under three separate scenarios.  First was a single Serial ATA drive with all capture, preview, temporary and production files stored on the same disk.  This test took 55:42:42 to complete. 

Then we installed a 15K RPM Seagate SCSI drive, recaptured the files to that drive, and directed all temporary, preview and production files to that drive.  This actually slowed performance very slightly, down to 55:46:22.  In our third scenario, we directed all temporary, preview and production files to drive C, keeping the main source files on drive D, which reduced rendering time down to 50:27.32, a 9% performance boost.   

Then we set up multiple picture in picture effects in Pinnacle Edition, the only program that displays frame rate during preview.  When pulling streams from the serial ATA drive, Edition played four streams without dropping frames, but started choking when we added a fifth.  In contrast, from the Seagate SCSI, Edition played six streams without dropping frames, an increase of 50%. 

The obvious difference in the results is that during rendering, a slower than real time event, the processor is the performance bottleneck, not the hard drives.  If you produce exotic, multilayer productions, and frequently need real time preview, fast SCSI drives are a must.  On the other hand, for most other productions, your money is better spent on a faster processor and adequate RAM.  Also, when running multiple drives, note that you’ll achieve better performance when storing all temporary files and writing to the system drive.   

Table 3:  Hard drive performance (performed on HP 4 2.4 GHz Pentium)

Other Components

Getting video into the computer is your next priority.  If you’re working with a DV camera, any FireWire card will do.  Otherwise, if you’re capturing from analog sources, or mixed DV and analog, you need a capture solution that addresses both formats.  If your primary goal is DVD production, consider purchasing an external USB 2.0 product like the ADS’ Instant DVD ($199), that converts analog video to MPEG-2 you can write directly in real time. 

On the other hand, if your goal is more general editing and distribution, consider products like Pinnacle’s MovieBox DV, also an external product ($199.95), that converts analog footage to DV, offering a higher quality starting point for editing and distribution than MPEG-2.  

If buying a new system, check your video editor’s system requirements before buying a new graphics card.  Pinnacle Edition, for example, offloads 3D rendering to the graphics card, so you’ll need a card with 3D muscle, and 64 MB of RAM.  VideoStudio, on the other hand, works well with the Matrox Parhelia card to provide real time analog preview. 

When working at the high end, choosing the right sound card is also critical.  For example, to benefit from the ASIO support in both Vegas and Premiere Pro, you’ll need a sound card with an ASIO driver.  Similarly, to produce 5.1 surround sound tracks, your sound card must be surround sound capable.   

Finally, you’ll need a DVD recorder to produce your DVDs.  After years of format wars between the DVD-RW and DVD+RW camps, we’re now starting to see “dual RW” drives like the Sony DRU-510 and the Pioneer A06 that support both formats.  This flexibility is critical when distributing disks widely, because many older DVD Player drives support one format or the other.  Being able to produce both types of media doubles your chances of producing a compatible disk.