• Adobe After Effects

  Problems with video stutter on Intel machine

  Posted by Tony Rath on July 16, 2008 at 3:39 pm

  Hi all,

  I have the following config:

  2 x 3.2 Quad-Core Intel Xeon
  16 Gb RAM
  NVIDIA GeForce 8800 GT
  4 x 1T internal hard drives set up as RAID
  Mac OSX 10.5.3
  AE CS3 (8.0.0)
  Prefences – MMU=120%; MRCS=20%; Enable Disk Cache-size=8Gb

  I am doing a complicated comp of a video wall.

  1. I have created a still image of a mosaic at 11520×6480 and animated it to Zoom out from a single frame in the mosaic to the entire mosaic. I rendered this out using Apple Pro Res to a 1440×1080 .mov @ about 350Mb.

  2. I then imported numerous smaller videos (5-8) at 320 x 240 to fit within the various frames of the mosaic as it zooms out. I have tried numerous codecs including Pro Res, Animation and JPEG. The individual videos weigh in at between 1.5 and 4 Mb.

  3. I created a null object that tracks the zoom out of the mosaic, and attached the smaller videos to the null object so that it looks like a video wall which zooms out to a mosaic which then transitions to a still image.

  The effect is suppose to be similar to the screensaver that comes with Leopard, except that a number of the still images in the mosaic are replaced with video.

  Sorry for the long explanation but wanted to give enough info.

  The problem is that on RAM Preview and rendering, the whole mess stutters, the back ground mosaic freezes, the individual small videos stutter, etc. With any more than 2 smaller videos, the whole comp stutters.

  I saw somewhere that this is a problem with Intel Macs and AE?

  Have not been able to find definite answers as I think I should have enough processing power to handle the comp.

  Any ideas or thoughts on where to start?

  Sorry for the long post.

  Tony Rath replied 17 years, 10 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Kevin Camp

  July 17, 2008 at 9:24 pm

  i don’t know that this is related to your problem… but i have some concerns about your set up…

  you mentioned that you have 4x1tb drives as a raid. i assume raid0 (striped, no parody), and i assume that this acts as both you boot drive and media storage.

  personally (and from what i’ve gathered as preferred), you may rather have your boot drive separate (both separate from the raid and on a separate controller). there are a few ways to go for this:

  -you could keep one drive (or purchase a new drive) and use that as your internal boot drive
  -add a sata2 card and put your riad drives into an external sata2 enclosure and connect them to the sata2 card.

  the negative is that you have to buy both a host adapter and an enclosure.

  -or-

  -add a sas or sata2 card that is capable of booting you mac, get an optical bay to hard drive conversion kit to install an addition hard drive or two i the second optical bay, then add a separate internal drive (either sas or sata2) in the 2nd optical bay. since there are kits for two drives, you can potentially create a small raid for the boot drive to either increase performance or for parody.

  this may save some money by not requiring an external enclosure. also, it would give you an option to get a sas drive which, although more expensive, should perform better as a boot drive and disk cache.

  you also mentioned that you are running ae 8.0.0, there have been 2 updates since then, so you may want to consider upgrading to 8.0.2. again, i’m not sure that this is the cause of your problem, but it’s probably worth upgrading.

  you also have your max ram cache setting at 20%… that seems low for as much ram as you have (16gb). unless you lowered it to overcome other problems, i think i’d increase it to 50-60% (60% should give you 2gb per core which is supposed to be the optimal amount for ae’s render engine).

  now, as for the actual stutter problem, it may be that since your cache and media live on the same drive that is creating some issues with reading and writing data… you may want to try turning your disk cache off to see if that helps at all…. note, that ae uses disk caching for other things other than rendered frames (which is what the memory & cache setting’s disk cache is), so there may still be some issues, but hopefully eliminating the cache of rendered frames may help some.

  you may also want to choose edit>purge>all to clear out as much ram and cache space as possible to see if that helps.

  if that helps some, but you still see some stutter later in the animation, you might try the purge frames option from the secret menu…. i can’t say i’ve ever used it for this purpose, but it may help. to do this, hold the shift key and choose preferences>general, then click the preference pulldown menu and choose secret from the bottom. set the purge frames value to a frame that is less than the frame where the problem begins (so if it starts stuttering at frame 30, try 20).

  Kevin Camp
  Senior Designer
  KCPQ, KMYQ & KRCW
• 

  Tony Rath

  July 19, 2008 at 12:26 am

  Thanks Kevin for your detailed answer.

  I have separated my boot disk from my data drive. I have 2-1Tb drives raided as my boot drive and photo work, and the other 2-1Tb drives raided for video work.

  I have tried the purge after 20 frames on the secret menu with no luck.

  I have played with the RAM cache, again with no luck.

  I am thinking of upgrading but hate to do it in the middle of a project just incase there are problems. That will be my last resort.

  I still can’t get more than three separate videos to play within the comp at a time. Three works fine. More than three and the freezing and stuttering happens.

  What I’ve resorted to is to create the video wall in batches of three and then pre-render. Then I take three batches of three videos and pre-render again. I end up with 9 videos playing with in a single rendered video. Lots of work though. Really frustrating when I think I have the power to build it straight.

  Thanks again for your thoughts.

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