Re: 2 Promise E-Class enougth for 6 HD Streams?

Hey Berenger, I just wanted to chime in and agree with a lot of the stuff Jordan said. Even for your low-stress edit suites doing ProRes work, I'd budget 3-streams of video per workstation as a minimum.

And, Jordan's dead on about the "theoretical direct attached" versus "real world Xsan" performance. 500MB/s writes and 900MB/s reads is attainable with for a good RAID in an Xsan. 1400MB/s is not.

However, as an Xsan administrator at a small corporate video shop, I just want to encourage you, your resellers and anyone else you deal with on this purchase to consider Active XRAIDs instead of Promise.

When Apple discontinued their old RAIDs and "blessed" Promise as the new Xsan solution, I assumed it was the only way to go -- and for a time it was the only option. Thankfully, though, Apple has wised up and allowed other RAIDs to be a part of Xsan, and some very good options are out there.

We've had Promise RAIDs here in our old Xsan, and I helped out a little with a larger (120TB) Promise RAID (Xsan) deployment down the street. Bad drives and controllers were not uncommon out of the box. Documentation was poor. Administration was difficult. And, performance was not what I hoped for.

We switched our smaller (20TB) Xsan over to Active XRAIDs this summer, and life has been much better. Everything worked -- nothing DOA. Management software is very easy to use. Setup and configuration was a breeze -- no complicated scripts to find and load, and all settings were very straight forward. Performance has been great. We're running eight edit suites -- five are pretty heavily used -- all working in DVCPROHD or ProResHQ. It all works fine with just two Active XRAID boxes.

Now, as an editor, it might not really matter to you that the storage is easier to administer and configure. I can't say Promise equipment would fail quicker than Active -- in fact, once everything got running, the Promise gear has been fairly stable. I can't even say categorically that Active is really faster -- I haven't done a fair head-to-head comparison. (I can say that my new Active-based Xsan is more than twice as fast as my old Promise-based one.)

But, I believe Active storage is better. Easier to use means less down time in the long run. More flexibility means more long term value. Higher quality components make a more reliable Xsan.

I don't really know you and your situation, so I can't say for sure what is best. But, I know that my life has been better since moving from Promise to Active storage, and I won't likely switch back. There are some solid vendors out there who sell Active and know Xsan -- if it was me, I'd find one of them and save some headaches.

Feel free to get in touch if you have any questions or want to chat. I don't work for anyone who sells things, so don't really have a dog in the fight. Just want to make sure people know there are some good Xsan storage options out there. Regardless of what you decide, good luck with the purchase!

Dave