Click to expand.Just checked a powermac manual. It says not to mix ECC and NECC in a pair. So, technically you could use NECC which I think is fine for your applications. From Apple website 'For users in mission-critical and compute-intensive environments, there's also the option of ECC (Error Correction Code) main memory, which allows automatic correction of single-bit errors and detection of multiple-bit errors.' If you save your files to disk periodically you will be fine. ECC is great for correcting for cosmic radiation alterations of single-bits in RAM. That's why ECC is used for space critical missions.
Memory (RAM) Computer DDR2 FB-DIMM SDRAM; Skip to page navigation. Filter (1) Computer DDR2 FB-DIMM SDRAM. Hot This Week. Apple Mac Pro Memory 16GB 800MHz DDR2 FB-DIMM ECC 4x4GB Kit MB194G/A. Free shipping. For Apple Mac Pro 3,1 2008, Micron 8GB 2x4GB PC2-6400F 800MHz Memory. Items 1 - 90 of 170 - 16.0GB (2x 8GB) PC3-10600 DDR3 1333MHz SO-DIMM 204 Pin CL9 SO-DIMM. 204 Pin CL9 SO-DIMM Memory Upgrade Kit for 2011 MacBook Pro models. 4.0GB Apple Qualified PC6400 DDR2 ECC 800MHz 240 Pin.
Unless you plan on going to the moon to make music, buy NECC. Click to expand.Yes and no. One bit of error is roughly equivalent to distortion level of 1/24 which is like 4% per sample (sounds like a lot), but then again, to be able to compare digital off-bit distortion to harmonic distortion of analog world for example, you cannot do comparison for one sample only (because analog is not discrete); one off-bit in one second is 1/(24.44100) distortion, which is practically nothing. One per million.
And it is even less than that if you use higher sampling rates (which IMHO you shouldn't if you make music for human ear and not for dogs and bats). Sell that ECC gig and buy as much regular ram as you need. By the way, if you do audio only, you would be fine with that gig - you'll only need more if you rely heavily on softsynths and samplers.
Audio processing only benefits from CPU, and having a gig is enough for now.