I am using a Mac pro Dual core 2.66GHz and thought that by adding a second DVD drive i would be able to cut the time to rip a pile of DVDs to MP4 by half. Unfortunately, when i run two versions of handbrake, and rip from each drive at the same time, the frame rate for each drive drops by more than half it would be if just one drive was running by itself. So, my hope of halving my overall rip time is not to be. Infact, if i do it running the two drives concurrently with two versions of the application, i actually increase the overall rip time.
What am i doing wrong? or is there no way to rip from two drives at the same time?
I have both drives set to cable select mode, as the mac handbook suggests, should i set one to master and one to slave?
Currently i frame rates between 60 and 90 fps for a single DVD this can drop down to 20 for each if i try two at once.
How to rip 2 DVDs at the same time without reducing fps
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For starters, are the files being created going to the same HDD? If so, stop it. Send the files to different times, otherwise you are likely to trash you drive. This WILL speed up your rips as I have learned from experience. I run multiple instances on my Quad G5 on a regular basis and lose maybe 5 - 8 Fps per instance over a single instance.
iamarchie,
It sounds like both Handbrake instances are trying to utilize only 1 of your cores, whereas it utilizes multiple cores when encoding just one DVD.
What does Activity Monitor report for Handbrake's CPU usage? Are all 4 cores being utilized? It should report at least 240% (4 x 60% per core).
Have you tried ripping your DVD to hard drive first and then encoding with Handbrake, while running a second Handbrake encoding process off DVD?
Download this benchmark test (rar password is v9a2) and run it with one instance of Handbrake. Then run it with two instances of Handbrake. Watch your cpu usage and see if it maxes out. Mirror.
From my personal experience, outputting two files to the same drive will not slow the encoding process down (unless you HDD is like 10 years old). You drive is capable of writing hundreds of megabits per second. Writing a couple megabits per second isn't going to damage it or cause it to sweat. So I would rule that out as the bottleneck.
It sounds like both Handbrake instances are trying to utilize only 1 of your cores, whereas it utilizes multiple cores when encoding just one DVD.
What does Activity Monitor report for Handbrake's CPU usage? Are all 4 cores being utilized? It should report at least 240% (4 x 60% per core).
Have you tried ripping your DVD to hard drive first and then encoding with Handbrake, while running a second Handbrake encoding process off DVD?
Download this benchmark test (rar password is v9a2) and run it with one instance of Handbrake. Then run it with two instances of Handbrake. Watch your cpu usage and see if it maxes out. Mirror.
From my personal experience, outputting two files to the same drive will not slow the encoding process down (unless you HDD is like 10 years old). You drive is capable of writing hundreds of megabits per second. Writing a couple megabits per second isn't going to damage it or cause it to sweat. So I would rule that out as the bottleneck.
If you've ever looked inside the MacPro optical drive area, you'll see that the two drives share the same IDE cable. This means that bandwidth performance is shared between these two drives. Any simultaneous reads can result in reduced performance on two mactheripper rip's going at the same time. The encode speed is way slower than any current HDD's, so writing the encoded output to the same drive will not be the limiting factor. The read drive may be a different story. I still feel that the biggest hit for simultaneous rips will be the initial read off the DVD. I've done two encodes at the same time reading from the a single 500GB SATA disk and writing the output to a different drive and they both ran the same as if single encoded.