can you recommend hd (RAID?) array? Transfer/editing workflow?

[Malcolm Hamilton]

Originally Posted by Mark Huang

Malcolm:
I have a 6 TB Caldigit HDPro for a few weeks now. I got my from B&H New York. It works great so far. HDOne is similar to HDPro but with with some cost saving measures. (1) HDOne does not have a removable RAID card. (2) The memory on the RAID card is not ungradlbe. (3) No redundant power supply (I think).Mark

Hi Mark... this is great, to hear from someone who's got something very much like the HDOne. (by the way, George... if I do come across an ExpressCard hub, I'll let you know)... Mark - - if I do end up going for the HDOne, am I a fool for pinching pennies (actually, quite a few pennies) and not getting the HDPro? How important is a removeable RAID card (and how important is it to be able to upgrade the memory on the RAID card)? As you perhaps read from one of my previous posts, if I sink money into a RAID array, I want to make sure I get something that will last me quite a while.
Cheers,
Malcolm

[Mark Huang]

Hi Malcolm:

From what I gathered from speaking with Caldigit supports, it really comes down to how the product can be supported. For example, if RAID card is bad then you can simply send the RAID card back instead of the entire unit. The chasis is very heavy even without any drive in it. About the cache memory, he told me unless you are doing 2K or your drive is about 75% full, you will likely not experience a significant impriovement over the standard 256 MB cache. Either way you will probably ends up spending +/- $1 per GB. HDOne is still 8-bay units so you will get the benefit from having multiple drive spindles. I configured my 6TB unit in RAID-5 with usable space just about 4.7TB. I've tried RAID-6 already. I think the performance penalty is just too much. With 8-drive unit, you can certainly spit the drive into different RAID array with different RAID configuration. I personally finds a big RAID-5 is sufficient.

When you buy a unit with drive already populated, the entire unit has 3 years warranty with a single point of contact. When you have problem with drive youc all Caldigit. When you have problem with RAID card you call Caldig hit. You get drive replacement from Caldigit and not from the hard drive manufacture. I find that a great value.

Now about using your own drive. Yes you can. Technically you can. But one of a big side effect is getting false positive on your RAID status or at worst multiple drive failure simply because the different hard drives don't work well together. This really has to do with different drive firmware and drive self-correction .... yada.. yada. I know this because I've worked in a big IT data centers. The same theory apply to big HP SAN or Dell PowerVault. And yes, take out the 750 GB drive out of Caldigit drive cartridge and put your own 1 TB drive does void the warranty on the 750 GB drive itself.

I say get the largest drive that your budget can allowed. If you work on different uncompressed videos from differernt projects, 6TB is not really out of this world. It gives you some decent breathing room and that is about it. The 8 TB unit to me is just simply cost prohibitive. The 4 TB unit probably has a very short usable life before I start looking for a replacement RAID again. So I picked a 6 TB unit.


IF, that is big IF, if you ever need to have multiple computers sharing one external RAID array, then Caldigit is the answer for you. Very shortly you will see a "switch" device from Calidigit. You can have multiple HDPro units or computers all connected to this "switch". All HDPro units will be visible to all computers at the same time.

I hope I have answered your question. If not then please let me know.


Thanks

Mark

[Evan Donn]

Originally Posted by Malcolm Hamilton

But what about security (eg., RAID 5)? I had a firewire drive fail on me a few months ago (I lost three weeks of work), and swore that my next hd setup would be RAIDed so that this would never happen again.
If fw 800 is just as fast as RAID, what do people do for peace of mind... just make a habit of always transferring footage to two fw drives?

The choice isn't between RAID and fw800, it's between fw800 and eSATA - you could go with a 2-drive fw800 RAID1 enclosure for redundancy. If you want RAID 5 you're probably better off just getting an eSATA solution.

[Malcolm Hamilton]

Originally Posted by Evan Donn

The choice isn't between RAID and fw800, it's between fw800 and eSATA - you could go with a 2-drive fw800 RAID1 enclosure for redundancy. If you want RAID 5 you're probably better off just getting an eSATA solution.

Now you have me wondering why I got it into my head that RAID 5 is what I want - - I'm sure I read this somewhere... that RAID 5 is both safe AND fast.
But from what you said earlier, maybe RAID 1 is just as fast (and just as safe)... at least when it comes to a MacBook Pro (THAT'S where things bottleneck). But maybe not quite as good, though, if I get a Mac Pro?
Thanks for your patience on this...
Malcolm

[Mark Huang]

Malcolm:

RAID-5 is actually "slower" than RAID-1 and RAID-0. RAID-0 is the fastest but it offers no data protection. RAID-1 is fast but there is a 50% over head of loosing space to the mirroring.

Check out Sonnet Tech here:
http://www.sonnettech.com/product/st...ons/index.html

If you care, this is my HDPro pkg:
http://gallery.mac.com/huang.mark#100021

Good luck and happy shopping.

Mark

[Noah Yuan-Vogel]

Originally Posted by Evan Donn

On the link I provided ( http://www.barefeats.com/hard94.html ) you can see the drop in speed for small random vs. large sequential - it is significant, cutting the read speeds into the 30MBs range - which is still plenty for multiple streams of XDCAM. My experience with HDV has been that for any single dual-core processor (i.e when editing on a Macbook) the bottleneck is the processor's ability to decode multiple streams rather than the drive's ability to stream them.

With regard to the barefeats graphs, the "small random write" test may not be as useful as you think. they dont say how small or how random and i believe it is only meant to compare the drives listed based on this arbitrary test. this may or may not correlate well with playing multiple simultaneous video streams from a single drive. i have seen certain data transaction patterns bring drives to only 3MBps, and booting to your OS likely happens at about 10MBps because there are so many small files for the system to load into RAM.

[Noah Yuan-Vogel]

Originally Posted by Dean Harrington

Looks like eSata will transfer 6 gigs per second and ethernet 1 gig per second according to the literature! Of course, I wonder what people are really getting? I'm using a Mac Book Pro intel with a teribit eSata drives in a kit set-up and they are fast but ... don't know the exact speeds.

I believe you mean you have a Terabyte drive, not Terabit.

I'm not sure 6 "gigs" per second* is an accurate number, maybe 2.5Gigabits per second at most. the theoretical max speed for esata using sata2 is 2.5Gbps and 1.25Gbps using sata1, and the theoretical max speed of Gigabit ethernet (GigE) is, well, 1 Gigabit per second. That works out to 300MBps for sata and 125MBps for GigE. however, in practice, youll likely not see much more than about 250MBps over sata (probably less if it is attached using a single pci-express lane which itself maxes out at 250MBps). and probably the only way youll see that kind of speed over a single esata connection, since hard drives run quite a bit slower than that, is with a port multiplied RAID or a RAID that has an internal controller and outputs over a single esata. GigE on the other hand in practice wont get you much more than 60-80MBps. and i believe you will have a hard time finding a NAS under $5k that breaks 20MBps.

*note the difference between bits (b) and Bytes (B)