Do be aware that no ATI card will give you hardware assisted Mercury Playback Engine support
For a list of supported nVidia CUDA cards go to the FAQ
If your power supply is compatible (the GTX 470 has 2 power connectors on the card) and is large enough (I use 850watt, you may be OK with 750watt) I would recommend the nVidia GTX 470
I'm running an i7 980 Extreme with 12GB RAM and a 1,000 watt PS. So hopefully this will be adequate for AVCHD work. I've been editing for a little over 10 years starting with Premiere 6.0 and working my way up as the technology has changed.
I have a ATI card now and didn't notice on the compatability chart the note next to the NVIDIA cards about GPU Acceleration so I just went to an ATI card. Thanks for point that out for me.
I'm confused though by your recommendation. The link you pointed me to lists 5 different NVIDIA cards with Acceleration but the GTX 470 is not among those listed.
Can you confirm for me that the GTX 470 does support GPU Accleration??
There are a number of nVidia cards officially supported, among them the 470, but a number of other nVidia cards can easily be made to work with hardware MPE as well. One does this with a simple modification of a text file, known as the 'hack' around here.
If you look at PPBM5 Benchmark and go to the results page and then click on the link to the MPE Performance gain chart, you will see all the nVidia cards that were submitted for the test and that work with hardware MPE.
Here is that summary:
All you need to do is navigate to C:\Program Files\Adobe\Adobe Premiere Pro CS5,
open the cuda_supported_cards.txt file and add a line like:
"GeForce GTX 480" without the quotes, save the file and you are ready to roll.
The forum list is out of date... PPro update 5.0.2 added GTX 470 support
Nvidia cuda enabled cards will give more performance because it will be able to use the mercury playback engine .
You can check the latest tested cards with MPE in this link :
And as per my expereince, nvidia driver updates are more robust than it's counterpart.