-
“Lag” in Final Cut Pro and uncompressed video
I have a question that might have an answer. We just got a G5 for some editing and I’m experianceing a strange “lag” when it comes to playing back incompressed footage. The lag is not a A/V sync issue, it’s a playback-lag that comes when pressing “PLAY” in Final Cut och QuickTime player. I’ve found this on all uncompressed 8-bit PAL material I’ve used.
To further explain this the lag only appers the first 0.5 to perhaps 1 or even two seconds. It varries quite a bit. I have not seen this issue on our system with DV or DV50 material. What I’m suspecting is to slow HD’s
HARDWARE:
– Dual G5/2.5 Ghz PCI-X
– 3GB RAM
– 2-port SATA PCI-X Card in 133Mhz slot
– AJA Kona LS in 100Mhz PCI-X SlotDRIVES TESTED:
– ACUTA 4-disk SATA RAID-5 (1 SATA connection to host computer, hardware RAID-5 in external disc cabinett)
– Firmteck 2-disc SATA (software striped)SOFTWARE:
– MacOSX Tiger 10.4.3
– Final Cut Pro 5.0.3
– AJA Kona LS 1.1.4 DriversI’ve done system tests with Kona System Test and got:
ACUTA: 75 MB/s read, 51 MB/s write
Firmteck: 112 MB/s read, 103 MB/s writeStill the “lag” is there. It’s a bit worse on the ACUTA, but it evident on the Firmteck and internal SATA-drives. It apper the first time I go to a clip usually. However, if I playback it so the lag disaperas, there is NO lag on that clip the next time I play it back (as long as I stay on the same clip). The same goes for playback of uncompressed files in QuickTime player. A slight, but very noticable lag beforce playback begins.
I guess what I’m wonder is if this is normal OSX/FCP behavior or if it might be my drives or configuration. My suspision is some kind of cachine by the system or something
-
2 Replies
-
No lags here to speak of either with the FW 800’s (G-RAID and LaCie) or Fibre Channel array. Maybe with 10bit from time to time, but definitely not with 8 bit.
Walter Biscardi, Jr.
https://www.biscardicreative.com“The Rough Cut,” an original short film premiering December 7th in full High Definition in Atlanta.
rsvp@biscardicreative.com to reserve seats.
https://www.theroughcutmovie.comNow editing “Good Eats” in HD for the Food Network
“I reject your reality and substitute my own!” – Adam Savage, Mythbusters
-
Very strange I must admit. I don’t think my last workingstation (Dual 1Ghz G4 with a SCSI-RAID, softwarestriped) suffered from this.
Reply to this Discussion! Login or Sign Up