There were three reasons for upgrading the Apple computing power from the current 24″ iMac:
Graphics Performance – All the video studio software packages (Wirecast etc) use the power of the Graphics Processing Unit (GPU) in the graphics adapter to do much of the processing work for video, as well as overall system performance. You need a balanced system and as you cannot upgrade the graphics adapters in an iMac the only option is to buy a new system.
Processing Performance – As well as the power of the GPU the overall system performance is important, not only for video studio software but when editing and transcoding (converting from one format to another) video files for uploading to youTube, Blip TV, Vimeo etc.
Expandability – to be able to add video capture cards to increase the number of cameras and video sources available for applications. The Mac Pro has three spare PCIe slots and these can be used to add cards such as the Intensity Pro (singles input from HDMI, component, s-video and video) and the Decklink SDI cards (single or dual port versions) from Blackmagic Design. S
The Mac Pro we ordered has 2 x 2.93 GHz 6 core Westmere processors, giving 12 cores in all, coupled with and an ATI Radeon 5870 Graphics adapter. This was the highest specification available at the time of ordering.
So what system performance improvement did we get over the current iMac with a 2.8GHz Core 2 Duo processor? We used the Geekbench benchmark program (also now available on the App store) running in 64 bit mode to test the two systems.
iMac 2.8GHz Dual Core (purchased Feb 2008)
Mac Pro Dual 2.93GHz Westmere
These test results show a nearly 6x performance improvement for the Mac Pro (and what a relief that was!) However benchmarks are clearly only an indication of how any system will perform.
When transcoding the last episode of A House in France we were able to run a real life comparison between the two systems. We use Apple Compressor (part of Final Cut Studio) to do the video conversions and we do at least three – YouTube, Apple TV and iPad. We started the YouTube conversion on both machines at the same time and the Mac Pro had finished all three before the first one finished on the iMac. In fact the Mac Pro processed 4 times the data in 80% of the time the iMac toook to do the first file! This makes a significant difference to our workflow and changes the transcoding from being a half day exercise to a long coffee break!
Our next benchmark will be comparing the two systems running Telestreams Wirecast!
Update 27 January 2011:
Cinebench
We have also run the Cinebench benchmark popular with may people in the video/graphics area:
System OpenGL CPU
iMac 12.9 1.52
Mac Pro 31.96 15.45
Mark
