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Soft Raid vs Hard raid. CPU utilization.
I’m looking into purchasing a new DAS raid solution again. I’m an indie producer/director that mostly works by myself. So fibrechannel, SAS and other such multituser solutions are more than I need. Instead I’m limiting my search to Thunderbolt connected DAS. I hold out hope of a possibility of a NAS which supports link aggregation playing nice with my (2014)Mac Pro via dual gBE. But though the math makes it seem possible. I am dubious.
My main question is about CPU overhead. I’ve done a bit of research during this evaluation around ‘soft-raid’ vs ‘hard-raid’. During previous upgrade cycles this question has popped up as well.
To clarify;
A ‘soft-raid’ (Drobo 5D, OWC Thunderbay 4)is one which uses the host computer to perform raid calculations and then sends the data to a dumb disk controller to route to appropriate disks. If it is raid 1 then it merely sends one copy of the data to two destinations. If however you are using raid 5, 6, 50 or 60, then the host computer has to calculate parity data for all your data it writes to the array. It also has to allocate the parity and data blocks across the raid volume in order to tolerate a disk failure.
A ‘hard-raid’ (Pegasus R4) has a dedicated controller that handles all of the math for parity data, drive allocation as well as disk host controller duties.
Why this matters to me, is that I have noticed a few reviews which ding products such as the Thunderbay 4 or Drobo 5D for essentially taking over one core of the host to run the raid. There are examples which show the host app running 100% utilization on one core for both Drobo and OWC products. I’ve not found examples for other soft-raid products. But then I think this may be because Drobo and OWC are two of the more popular DAS products. Hence garnering more reviews.
I am curious if anyone has any wisdom to share on real world experience with CPU utilization, raid arrays and video production.
I’ve noticed that most of the hard date type websites such as Anandtech and storagereview focus on multiuser scenarios or transactional database types of use. Not so much HD playback and content creation.Salients: PP cc2016, nMP 6 core 32gb 1tb SSD. Mostly editing with some effecty music video style nonsense.
Pretty much all 29.97 or 23.97 1080p. Though I have been doing some animation in 4k and then bringing it in at HD.