Where is the bottleneck? at DVinfo.net

Jordan Berry · April 11th, 2009, 12:01 PM

Hello,

My Setup:

Macbook Pro 17" Duo 2 Core 2.5Ghz \ 4GB Ram \ GeForce 8600M GT 512mb / 200GB 7.2k HD

Software: Final Cut Pro 6.0.5

Footage: 2x Streams of AVCHD transcoded to Pro Res 422 (in FCP) 1920 x 1080 29.97fps.

I'm watching the edited multicam sequence in FCP in a small window. The preview is set to draft. RT set to unlimited. And my macbook just can't play it back smoothly!

I've tried restarting and FCP is the only program running.

Suggestions?

James Venturi · April 11th, 2009, 12:17 PM

What about playing the footage from an external FW800 drive with plenty of room?

Shaun Roemich · April 11th, 2009, 12:22 PM

Sounds like your bottle neck is indeed the harddrive/codec issue. You're trying to pull 35+MBytes per second from 2 different areas of the disc (2 media files) from a system drive. Sounds like a recipe for failure in a laptop to me.

William Hohauser · April 11th, 2009, 04:06 PM

I third the suggestion to transfer the footage to an external FireWire800 drive. This is just too much for the internal drive to deal with.

Jordan Berry · April 11th, 2009, 04:31 PM

Quote:

Originally Posted by Shaun Roemich

Sounds like your bottle neck is indeed the harddrive/codec issue. You're trying to pull 35+MBytes per second from 2 different areas of the disc (2 media files) from a system drive. Sounds like a recipe for failure in a laptop to me.

Yeah the 1Gb per minute of Pro Res 422 is quite nasty.

I'm going to run a benchmark on my HD to see what I could possibly pull of it.

I actually don't own a Firewire HD so I'll need to get one in order to test that out. Makes sense to me though.

I hear xbench isn't very reliable...

http://img.skitch.com/20090411-rj9kb...r1n7sump4m.jpg

I checked the activity graph and it showed a peak of 30.65MB/s after playing the multi-clip sequence.

EDIT: I tried putting one of the files on a external USB drive. It plays back smoothly. The HD is definitely the bottleneck.

Robert Lane · April 12th, 2009, 10:52 AM

First, is the sequence fully rendered?

You can't expect high-performance real-time playback from any MBP most especially from the single internal HDD, there just isn't enough data-pipeline available on the mainboard.

An external drive would help substantially but it would need to be eSATA connected via the ExpressCard adapter for there to be a real benefit. FW800 doesn't have enough bandwidth to support multiple-stream HD playback however a fully-rendered sequence will have an 80% chance of getting smooth playback with the sequence settings you're using.

April 11th, 2009, 12:01 PM	#1
Jordan Berry Regular Crew Join Date: Sep 2007 Location: Kansas City, MO Posts: 128	Where is the bottleneck? Hello, My Setup: Macbook Pro 17" Duo 2 Core 2.5Ghz \ 4GB Ram \ GeForce 8600M GT 512mb / 200GB 7.2k HD Software: Final Cut Pro 6.0.5 Footage: 2x Streams of AVCHD transcoded to Pro Res 422 (in FCP) 1920 x 1080 29.97fps. I'm watching the edited multicam sequence in FCP in a small window. The preview is set to draft. RT set to unlimited. And my macbook just can't play it back smoothly! I've tried restarting and FCP is the only program running. Suggestions? __________________ BerryGood Video LLC Kansas City, Missouri

April 11th, 2009, 12:17 PM	#2
James Venturi Regular Crew Join Date: Sep 2008 Location: NYC Posts: 81	Idea What about playing the footage from an external FW800 drive with plenty of room?

April 11th, 2009, 12:22 PM	#3
Shaun Roemich Inner Circle Join Date: Sep 2002 Location: Vancouver, British Columbia (formerly Winnipeg, Manitoba) Canada Posts: 4,088	Sounds like your bottle neck is indeed the harddrive/codec issue. You're trying to pull 35+MBytes per second from 2 different areas of the disc (2 media files) from a system drive. Sounds like a recipe for failure in a laptop to me. __________________ Shaun C. Roemich Road Dog Media - Vancouver, BC - Videographer - Webcaster www.roaddogmedia.ca Blog: http://roaddogmedia.wordpress.com/

April 11th, 2009, 04:06 PM	#4
William Hohauser Inner Circle Join Date: Dec 2005 Location: New York City Posts: 2,650	I third the suggestion to transfer the footage to an external FireWire800 drive. This is just too much for the internal drive to deal with. __________________ William Hohauser - New York City Producer/Edit/Camera/Animation

April 12th, 2009, 10:52 AM	#6
Robert Lane Go Go Godzilla Join Date: Nov 2004 Location: Scottsdale, AZ USA Posts: 2,823 Images: 15	First, is the sequence fully rendered? You can't expect high-performance real-time playback from any MBP most especially from the single internal HDD, there just isn't enough data-pipeline available on the mainboard. An external drive would help substantially but it would need to be eSATA connected via the ExpressCard adapter for there to be a real benefit. FW800 doesn't have enough bandwidth to support multiple-stream HD playback however a fully-rendered sequence will have an 80% chance of getting smooth playback with the sequence settings you're using.