Changing my recommendation re fusion drives vs SSD’s

[Rick Lang]

Further to John’s observations about the speed of the internal SSDs, MacWorld just published their benchmark of the new Pegasus2 R6, on a Mac Pro using RAID 5:

Drive Black Magic Write Black Magic Read
Pegasus2 R6 (7200-rpm hard drives) 833 742 MB/s

Looking at Wikipedia:
The storage and data rates for the widely used YCbCr 4:2:2 chroma subsampling uncompressed video are listed below:

1080i and 1080p HDTV uncompressed
8 bit @ 1920 x 1080 @ 24fps = 95 MB per/sec, or 334 GB per/hr.
10 bit @ 1920 x 1080 @ 24fps = 127 MB per/sec, or 445 GB per/hr.

8 bit @ 1920 x 1080 @ 25fps = 99 MB per/sec, or 348 GB per/hr.
10 bit @ 1920 x 1080 @ 25fps = 132 MB per/sec, or 463 GB per/hr.

8 bit @ 1920 x 1080 @ 29.97fps = 119 MB per/sec, or 417 GB per/hr.
10 bit @ 1920 x 1080 @ 29.97fps = 158 MB per/sec, or 556 GB per/hr.

Clearly HD is not a concern for very short duration work, but when you quadruple it for 4K (UHD) data rates:
10 bit @ 3840 x 2160 @ 29.97fps = 624 MB per/sec, or 2224 GB per/hr.

Clearly one isn’t going to use the internal flash for storage of 4K video, but are the Pegasus2 write and read speeds going to provide a comfortable performance margin for 4K workflows? Or is an 8-bay RAID 5/6, the preferred and highly recommended option? Thanks for any comment you may have.

Rick Lang

iMac 27” 2.8GHz i7 16GB

[Jeremy Garchow]

Those are uncompressed numbers. My guess is that you’ll be using ProRes.

Aja makes a handy data calculator were you can calculate/observe, forwards and backwards, data rate, storage requirements, time allotments.

iOS:

https://itunes.apple.com/us/app/aja-datacalc/id343454572?mt=8

Mac:

https://static.aja.com/ajashare/ajasoftware/AJA_DataCalc_Mac.zip

[Rick Lang]

Jeremy, you are correct that normally ProRes 4:2:2 HQ would be the codec of choice and that’s about 110 MB/s (884 Mbps) for 4K work if memory serves me correctly. I was curious what impact uncompressed video would be though to see if that was even feasible on the Pegasus2 R6. It appears it may be possible looking at the numbers but I’ve no experience with 4K, ergo my post.

I know an 8-bay will handle it, but that starts to get expensive. A Pegasus2 R4 in RAID 0 might as well but I hope to avoid that temptation and have the data redundancy of RAID 5 or 6. I remember someone advising to steer clear of a 6-bay configuration, but I’m not aware of the rationale for that warning. Perhaps it was just that RAID 6 on an 8-bay is the best insurance and performance.

Thanks for your advice re the calculator as I had forgotten that. I’ll pick that up now.

Rick Lang

iMac 27” 2.8GHz i7 16GB

[Jeremy Garchow]

A Pegasus will handle any form of ProRes. I’d buy the most you can afford, and work in ProRes.

Will you need real time uncompressed 4k edit, playback, and effects? You are going to need a small closet full of drives!

Raid 6 takes away two drives worth of capacity, so if you want Raid6, you’ll want an 8 bay.

A 32TB 8x4TB Raid6 stripe becomes 24TB formatted.

Jeremy

[Rick Lang]

Thanks, Jeremy. I’m going to take your advice and stay with a ProRes workflow. Makes everything manageable.

Rick Lang

iMac 27” 2.8GHz i7 16GB

[Joe Valenti]

Hello Oliver,

I trust your judgement. Would you recommend the standard 1TB Fusion drive over the 1TB Flash Upgrade in the new 5K IMAC Retina? We’re not editing off the drive, just running Premiere, SpeedGrade and Media Encoder. Storage is currently Thunderbolt 2 and a fair amount of our footage is 4K UHD. We’ll save some cash and upgrade all the ram to 32GB ourselves. Also planning to go with their higher-end graphic card and processor. Wanted to purchase a few of these for the 4K editors so we can really see our rushes.

By the way – our world is single stream only: We’re a stock video pipeline.

Many thanks,

Joe Valenti
Clippn
http://www.clippn.com