Which RAID for FCPX?

[Gary Adcock]

[Jason Jenkins] “Will a faster RAID increase realtime performance? In other words, will it decrease the need to render?”

That would depend on your setup.

the short answer is yes.

Render times are dependant on Processor speed, but handling of the content is done by drives, and the faster your drives the faster your computer can handle moving the data from one place to another.

This is especially important when moving massive files of data, as all of the read / writes are faster, allowing the CPU’s to work at optimium speed because they are not dealing with

gary adcock
Studio37

Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, IL

https://blogs.creativecow.net/24640

[Jason Jenkins]

[gary adcock] “handling of the content is done by drives, and the faster your drives the faster your computer can handle moving the data from one place to another.

This is especially important when moving massive files of data”

This is one of the reasons I wonder how much a fast RAID would benefit me; because the AVCHD files I work with are relatively small and don’t require a lot of bandwidth.

Jason Jenkins
Flowmotion Media
Video production… with style!

[Cy Starkman]

Hi, I don’t the answer to my question, but I know the answer to yours.

Increasing the speed of your storage will improve the following

– ingest speed restricted by the commection bandwidth of the camera / device (bring on thunderbolt cameras)
– playback rate of footage
– playback rate of multiple streams of footage, limited by qty of streams and how fragmented they are
– performance of scratch disk if you move it to the fast storage
– will improve the render speed of >previews< IF the potential render rate is faster than your current read/write
– restricted by qty of streams, the preview renderer has faster shared access to content while you keep working
– final render speed IF the potential render rate is faster than your current read/write
– copy speed between storage devices limited to the bandwidth of the slowest device

Notes
– qty of streams refers to how many simultaneous video tracks and the codec/s, size, color depth of the tracks
– if your computer is not fast enough to decode and present the track in real time, its maximum frame rate will apply

You can also improve performance significantly by thinking about your storage devices as video “tapes” in play/rec machines. If you play and record to the same device it is potentially only half as fast (at best). Using two drives one as playback and one as record (render) will boost performance to the limit of your computer or the slowest storage device. If you need to go multiple generations you can then (in your mind) swap so the record becomes the play (since that is where your new track is).

This method does require that you have the devices on separate I/O buses, for example two drives on 1 USB bus would be terrible (it is faster to copy from USB to internal and then back than USB to USB). Likewise if you had a FireWire 800 and a USB2 it will only go as fast as the USB (it is the slowest). USB can also only read or write not both. Multiple ports on a computer MAY share the same bus, so you have to know that detail.

But IF the bus had the capacity to transfer information faster than both the read and write potential of both storage devices and if the bus supported simultaneous read write, then they could both be on the same bus without penalty.

So back to your Pegasus R# question.
An R6 can read and write at an average of 500MB/s (raid 5) or 600MB/s (raid 0) across the device
An R4 is a wee bit slower in (raid 0) and much slower in (raid 5) with bigger individual files

Best compare I have seen
https://hamed.dk/blog/101-pegasus-r4-r6-review?start=1

Thunderbolt can read and write at the same time both at 1.25GB/sec so….

If you can afford it then total domination would occur with 4 x Pegasus R(4 or 6) configured so you have two RAID devices made of 2 Pegasus each. That would mean you could playback and record 1.25GB/sec (thunderbolt speed)

If what I interpret is correct then the 27″iMac has two thunderbolt buses, 1 per port. I suppose you could duplicate the above per port but we are getting quite exotic and I have no idea if a RAID could bridge two thunderbolt buses, if it did then you might get something around the order of 2.5GB/sec simultaneous read/write. (this is like copying a DVD in 2 secs)

Can an iMac / mini / MBP decode, process, encode and maybe display 1.25GB of data per second, or even 600MB. I don’t know. Would a networked render farm be able to do it or would the network be too slow, no idea.

And to tail off from that point…

The potential performance increase will be governed by what you do to video. If you edit video more improvement will be realized than if you process video doing all kinds of mad effects, blending layers, masks etc etc. All that processing is done in CPU/GPU so regardless if you can play or record the 10 streams of video in real time, if that decode-process-encode point in between takes 1minute per frame, it takes that (excluding grabbing/temp stashing/recording all the footage required to achieve it)

Potentially if you use a non destructive codec that your computer can decode/encode in real time then you could apply effects over generations (no loss to quality) and do it faster than composite effects at once but by jove you’d have to know the render performance of each effect intimately.

In the mean time depending on your system config, for a few bucks get a record storage device and have it on a separate bus. If your dec/pro/enc is slower than USB can write You can go FW800 > USB and if you get devices with 800 and USB plugs then you can physically swap ports so what you just wrote to (as fast as your computer could process) becomes the fast player.

Just for laughs (but serious) to boost more if the ambient temp and drives are really hot put em on ice to cool em down and keep them performing (I have done this with remarkable results)

Hope that helps : )