Modified GTX 260 for Premiere Pro

[Henry Li]

Thanks Oliver and Rudi!

I have some follow up questions. First, let me explain the situation.

1. I have a clip that contains 4 layers of 4K R3D files (original layer + 1 layer of mask + another layer of mask + 1 layer of rotoscope). The footage was shot in Redcode 36, and are dynamically linked to After Effects.

2. I turn off GPU acceleration (so, software only), the bar goes red in the timeline. I activate GPU acceleration, the bar goes yellow in the timeline. Now, correct me if I'm wrong, but that yellow line means the clip is now GPU accelerated and may be possible to play it back in real time (at some resolution...maybe 1/16?).

3. I play the clip. The audio plays fine, the video doesn't play at all, no matter what the playback resolution is set at. It just stops cold on the first frame.

4. I check Activity Monitor. The CPU is barely hitting 40%, the RAM has a few GB free.


QUESTIONS:

1 a) Sooooo...is it possible that the bottle neck is the hard drive read and write speed?

I have an external Raid drive (4 x 2TB) connected with eSata. I tested it. The read and write speed are 125MB (read) and 105MB (write). Right now, it's limited by the eSata card I have which caps everything around 125MB. If I get something like this: http://eshop.macsales.com/item/Newer Technology/MXPCIE6GS2/

I can get sustained rates of 220 MB (read) and 180 (write) from my external drive (according to LaCie's website).

b) If I'm editing 4 layers of 4K files at 36 MB each, in theory, I need sustained read and write speeds of 144MB (4 x 36MB) minimum, correct? Am I way off base here?

2. Another thing that's confusing me is how the playback resolution factors into all this. If I set it to 1/16, what sustained read and write speeds do I need to play back the clip (all 4 layers) in real time? 1/16 x 144 MB = 9 MB. Do I only need 9MB of sustained read and write speeds to play back the clip in real time? Is that how it works? If so, how come I can't get it to play back in real time?

3) Is there a software (for OSX 10.6.5) that can measure whether or not the hard drive read and write speeds are peaking? Apps like AJA System Test don't measure the hard drive when in use. I'd like to determine if the hard drive read and write speeds are being strained/ pushed to the max.

I'd appreciate any help. Thanks!

 

[Oliver Rabinovitch]

3) Is there a software (for OSX 10.6.5) that can measure whether or not the hard drive read and write speeds are peaking? A
!

Impressively thorough breakdown of the data rates! I can't confirm or deny the correctness of your calculations, but here's the first thing that comes to my mind to explain the lag you're getting:

From your quote above, it sounds like you're running Premiere on a Mac in OSX. That's probably the issue right there, and would explain why you dug so deep into the data rates, that is, so we'd have a cross-OS platform to make comparisons from. I don't have 1st hand experience running Premiere on Mac hardware, let alone on an OSX-based software. My suspicion is you can't expect to get PC-based Premiere CUDA performance in an equivalent Mac hardware/software environment. Either it's not possible yet, or the Mac hardware would have to be super beefy.

What do you think?

 

[Benoît-Joan Clariana-Roig]

Could do you put those files or another short example of premiere pro project you can't playback properly somewhere on a FTP ?