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Windows 7 Performance for Streaming Encoding
A Windows 7 upgrade can cost more than $300 for the software alone -- is it worth it if you're a streaming producer looking to shave encoding times? Well, that's what I detail in this article.
By way of background, I had a great testbed for this - a dual processor, quad core 3.33 Ghz Xeon (Nehalem-based) computer from custom workstation manufacturer Puget Systems. Puget supplied the workstation with three system drives in an easily swappable drive bay so I could change operating systems in a matter of moments. Thus equipped, I loaded a number of programs on the three system drives, including Adobe Media Encoder, On 2 Flix Pro, Rhozet Carbon Coder, Sorenson Squeeze and Telestream Episode, and ran the encoding trials on each platform. Click over to the main article to see the results.
The Puget Systems Genesis II workstation.
More specifically, the system was a Genesis II, liquid-cooled system with 12 GB of RAM, and all operating systems were 64-bit versions. Though the system was a soon-to-be returned loaner, I went through the typical buying process; pre-purchase conference, email notifications regarding the system's progress through manufacturing and testing, with thermal photographs showing the system's heat characteristics. The system included final test results with the tester's name so I'd know who to call if something went wrong (nothing did). It was a fun process, and the computer proved to be a real workhorse.
I used the system to perform multi-OS editing and rendering benchmarks for Adobe Premiere Pro and Sony Vegas, which you can read about here on the Digital Content Producer website. In the test resported here, I focused solely on encoding performance, but let's start with a metric that we all care about - boot time.
Table 1: Boot time.
As you can see in Table 1, there's not a lot of difference between the three OS; with XP taking ten seconds longer than Windows 7, which is two seconds quicker than Vista. Note that each boot time includes about 1:50 (min:sec) of hardware boot before the operating system even started working.
Adobe Media Encoder
After booting up, I ran the Adobe Media Encoder and rendered my 1:40 720p test file into the formats shown in Table 2. First was MPEG-2, where XP was actually 6 seconds (and 8.22%) faster than Vista, and 5 seconds (and 6.85%) faster than Windows 7. Windows 7 was 1 second faster than Vista, which translated to 1.27%. Nothing really significant here.
Table 2. Adobe Media Encoder running XP, Vista and Windows 7.
Windows XP was also fastest when rendering the same file to H.264 format, with Vista again the slowest. This reversed when producing FLV files, where Windows 7 was 18.75% faster than XP, and 10.34% faster than Vista. These differences are significant, but nowhere near the difference I saw with Windows Media files, where Windows 7 was a real burner, shaving around 40% off encoding times over Vista and XP. Taking all four tests into account, XP was the slowest (7:24) and Windows 7 the fastest, though most of the difference related to Windows Media encoding.
As mentioned, these tests are rendering only. When I tested project rendering and output to these formats for Digital Content Producer, the ~40% output advantage for Windows Media tempered to about 15%. Still significant, but much less than ~40%. Accordingly, if you'll be rendering and encoding to Windows Media format, think 15%; if encoding only, think 40%.
With Squeeze, I used the same source file and encoded to MPEG-2, H.264, VP6 and WMV formats. Here the results were much less dramatic, and XP proved the overall performance leader. If you're an XP Squeeze user, it's tough to create a performance-based scenario where it makes sense to upgrade to Windows 7, though if you're running Vista and producing lots of WMV files, the 9.16% time saving might look alluring.
Table 3. Sorenson Squeeze running XP, ista and Windows 7.
I ran a trial version of Episode on all three OSs, which only encodes the first 30 seconds of the test file, so don't compare these encoding times with any other programs. Here, XP was the fastest, Vista the slowest, and Windows 7 pretty comfortably in between. If you're running XP, there's no compelling reason to consider Windows 7, but Vista users would get a modest speed boost on all three formats.
Table 4. Episode Pro running XP, Vista and Windows 7.
Flix Pro produced wildly different results each time I tested. For example, encoding my HD test file to FLV format the first time on Windows 7 took 6:40; the second 4:30, the third 6:20. Ditto for the other operating systems. The only conclusion that I could draw was that I could draw no conclusion.
Rhozet Carbon Coder
I ran several tests with Carbon Coder. First I encoded two ~ 20 minute HDV files to four formats (WMV, VP6, H.264 and Blu-ray compatible MPEG-2) in a single batch, and then substituted an iPod encoding template for the MPEG-2 file for the second batch. In the first batch, XP was the fastest, in the second, the slowest, though the difference with Windows 7 was less than 4% either way. Vista was slowest in the first batch, fastest in the second, though again, the differences were nothing to upgrade about.
Table 5. Carbon Coder batch tests with the three operating systems.
In the second set of tests, I encoded sixteen files to the same FLV, H.264 and WMV formats. Here, XP was the overall slowest and Windows 7 the fastest, with the greatest disparity in the WMV encoding trials. If you're currently running XP, you might consider upgrading to Windows 7 if you're producing either H.264 or WMV files; if Vista, WMV encoders might also find the 9% performance boost worthwhile.
Table 6. Second round of Carbon Coder tests.
Back when it was first released, I avoided Vista like the plague because I loathed the interface and because it was slower than XP, by up to 25% in some of my early tests. I still loath the interface, but it's clear that Microsoft has goosed performance a good bit in subsequent updates.
Though some interface areas of Windows 7 are equally awful (the search function in particular), at least you don't have the performance issue to worry about. If you're buying a new computer, I would choose Windows 7 over Vista.
On the other hand, other than the Adobe Media Encoder Windows Media Encode only scenario, I don't see any compelling, performance-related reason to upgrade to Windows 7, though Carbon Coder users might find the acceleration in H.264 and WMV encoding worth chasing.