• Blackmagic Design

  Speed Test and Raid or no Raid considerations.

  Posted by Steve Lim on May 16, 2005 at 6:50 am

  Hi all,

  We have a new G5 with 2 400GB drives installed _internally_. I initially decided to raid stripe them together into one big 800GB volume. I ASSUMED that raid would be a good idea. Now I’m hearing from people that it is a BAD idea to combine your data with the same drive that your OS runs from. Is this true?

  I have 2 options

  1. 2 Internal 400GB in raid as one 800GB Volume (OS and Data share the same volume)
  2. 2 Internal 400GB as seperate volumes 1 * 400GB for the OS and 1* 400GB for the data.

  Which setup is faster? Or safer?

  Secondly my speed test has come up with the following benchmarks.

  Disk Read 87.0 MB/s
  Disk Write 108.1 MB/s

  Is this fast enough for SD? We would like to capture and output to betaSP and DV.

  Thanks,

  Kaspar Kallas replied 21 years ago 3 Members · 3 Replies
• 3 Replies

• 

  Kaspar Kallas

  May 16, 2005 at 7:11 am

  this why it is a badi idea: if one of the disks fails you loose data on both.
  this is why it is a good idea: you get more than on stream of uncompressed SD @ 10 bit

  my recomandation would be to get yourself an external FW drive for yer system and project fails – so when something happens with yer external raid then you would only loose the media that you can recapture

  if you are willing to spend a bit more than you could get yer self a swift data 200 (https://www.transintl.com/store/category.cfm?Category=2490) with the sonnet option then you would be able to add 3 extra drives to yer system so all three drives could be internal and you would have 2 slots for upgrade

  I use my self the latest version – very happy with this, I have 4 drive raid0 and a system drive all inside my mac, I get @ empty drives 210+MB/s rw

  -Kaspar
• 

  Markh

  May 17, 2005 at 1:15 am

  >”this is why it is a good idea: you get more than on stream of uncompressed SD @ 10 bit”

  Are you suggesting a 2x400GB RAID 0 is enough for two streams of uncompressed SD at 10-bit?

  -m
• 

  Kaspar Kallas

  May 17, 2005 at 6:38 am

  for sure SD pal @ 10 bit is 22.1MB/s
  and SD ntcs @ 10 bit is 23.1MB/s

  single sata drive should not go lower than 30MB/s on inner circles of the disk – when empty you should expect 55MB/s and stripeset almost doubles the preformance

  -Kaspar

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