I fell across this whilst searching on the net http://www.pcguide.com/ref/hdd/perf/raid/index.htm it has a comprehensive coverage in not too difficult language of all the benefits/pitfalls of all the various raid systems. Good bedtime reading!!

Julian

@cm said:

one more time ... be warned ... raid controllers behave different. even the Xraid has to be configured to give you best throughput for streaming

Hi Christian,

I use a Kano Tech (super-quiet) external 4 drive SATA rack for all my sample libraries, but they are not setup in any kind of RAID. They are JBOD (just a bunch of disks). So far, things are really working well, but are you suggesting that I should try a software RAID with these disks? I've always understood that for sample streaming RAID may not be the best solution, however, manually distributing the libraries across 4 drives as I've done may not always be a match for a particular orchestration. Maybe a certain piece uses many samples only from a single drive. For this reason I'm asking if I'd be better off with a RAID setup. What do you think?
Thanks,
Gary

@Jack Weaver said:

However, since cm has pretty much confirmed that VI will sit comfortably on one 500GB drive - you don't necessarily need a RAID configuration.

Jack -- I think that although the entire library will FIT on a 500GB drive, you'd be putting that single drive through the wringer trying to make it access and spit out enough samples for a large orchestration. (CM -- please correct my if I'm wrong.) Maybe one of the newer drives with a 16MB cache, but I would doubt it.

@Another User said:

... but are you suggesting that I should try a software RAID ...[code:1:7fb1e74b40]
gary, no i'm not (assuming your rack is connected via FW800 or actually sATA) - i've just noticed it is more performant in most cases as a (usually cheap) hardware raid, because of the special demands of audio streaming.

i'd say software raid adds 3-5% load to the system - so if you need just these 5% performance (for an additional instance of VI, for some other plugin) the software raid would be contraproductive.

to spread a library *right* across multiple drives can be tricky and depends of course also on the type of performance you have to arrange.

the most significant value for a drive is IMO the average seektime (for our needs), thats why NCQ (found with SCSI and some sATA) is the superior thechnology when we look at sampling.

christian[/code:1:7fb1e74b40]

Christian -- not sure I a understand what you mean. (BTW, I have a SATA card connecting my 4 drive rack). I understand you do not prefer software RAID, but are you saying that a hardware RAID is better than manually spreading the library across 4 drives. Also, what is NCQ? Thanks.

Gary

gary, sATA drives connected via sATA is a very good solution - i'd say no need to experiment with software raid.

NCQ is Native Command Queuing (aka Tagged Command Queuing) - a technology originating from SCSI.
in a nutshell: if the operating system (OS) requests data (say portion A-B-C-D, 512 bytes each) which resides in different sectors of the harddrive NCQ can re-order the requests (say to B-D-A-C) to minimize the movement of the heads (in the harddrive) - this reduces seektime to the half (average 8,5 ms to 4,5). this happens in the interface sitting on the harddrive itself.

a hardware raid makes only sense, if you can be sure it does not try to cache files (and so effectively reducing your performance) and also uses NCQ _and_ an intelligent read-algorithm.
my example here:
IBM expansion unit SCSI 160 drives, i5 controller, raid5 = ~20 MB/s
EONstore (sATA drives to SCSI), 39160 controller, raid 5 = ~120 MB/s

your sATA drives should give you around 60 MB/s and i'd assume you will not reach this limit with any arrangement, especially if the (instumental) sections are spread across several drives. sATA I (the bus itself) is 150 MB/s - capital B means Bytes

christian

christian

Thanks Christian -- very helpful info.
Best,
Gary

@Guy said:

-G5 Quad, 6.5 GB RAM
-1st internal drive 250GB
-2nd internal drive 500GB (being installed)

-Logic Pro

-VSL Pro Ed and Perf Set
-VI Library

-Redmatica

I'm looking seriously to get SOHORAID SR3600/2 X 500GB from my local Mac retailer. Will this carry the load? Opinions....


http://www.stardom.com.tw/main_e.htm Click on SR3000 Series.


Jack,

Thanks for that explanation, I actually understood it! [:D]

garylionelli,

I currently use a single drive for VSL orchestral mockups. I usually run into a Digidesign coreAudio issue long before I ran into drive issues. So perhaps I did not have the opportunity to hit the ceiling of drive throughput. Perhaps after NAMM and I see MIR so I can figure out what shape my VI system will eventually be and get a new interface for Logic other than having to use my Digi 192 I will have more first hand experience. I don't have the real world VSL experience of cm, naturallly. However, I did own a company that built Fibre Channel networks for nonlinear video workstations, Pro Tools and digital film dubbers so I have a feel for the crude basics involved.

There are a lot of ways to do this. I haven't checked recently for pricing on the higher rotational speed SATA drives but per the Seagate website:
Barracuda 7200-RPM drives with SATA NCQ match performance of 10K SATA drives at much higher capacity and better price per gigabyte (in apps with higher-transaction workloads)

You want to access all those little .wav files as quickly as possible. Having them on more than one disk would be fine. Higher rotation speeds aid in faster seek times.

I haven't yet seen the utility that is supposed to come along with VI for linking the instruments with the samples, a la EXSManager (which to the best of my knowledge won't work with VI since there are no EXS instruments). However I can envision having two external SATA drives (in JBOD mode) each with the full VI on it - using one to link, say strings, and the other to lin to winds, brass, percussion.

This way you could have the advantage of accessing sample files from multiple disks for speed and, in the case of catastrophic failure you would still have a full copy of VI to use in the mean time.

Of course, gary, this is assuming that you aren't recording audio in addition to composing with VSL/VI. Currently, I use a second, internal SATA for recording audio from Pro Tools. I generally don't record with Logic.

cm is certainly correct about the throughput of SATA being more than adequate - and seemingly everything else regarding this for that matter. He should be considered the final authority on these matters. You might not need software RAID for speed. RAID mirroring might be nice though.

I sure do look forward to going to NAMM and finally figuring out what's going to be required for the rest of the system, including the PC that hosts MIR. Everything is a bit on hold for me until that time.

Hmm, maybe I should ask cm now what I need? OK, I have one G5, Pro Tools HD2 Accel w/ 192 interface and Logic. I record audio in Pro Tools, MIDI in Logic and mix in Pro Tools. I have Pro Cube w/ Performance Set & most of the Horizon stuff - all in EXS. I've ordered VI and think I want MIR.
I need to get another audio interface (probably FireWire) for Logic because of the Digidesign coreAudio problems. I am replacing all my FireWire drives with an external SATA drive system (JBOD, RAID?). That will take up my third and final PCI slot.

What will I need for a MIR PC? How do I link the MIR PC with the G5 with Logic on it. Can I still mix in Pro Tools? I don't mind changing my methodology as VI will make it all worthwhile. However, I have a ton of TDM plugins. Note: Pro Tools v7 doesn't work with Logic in TDM mode. Eventually it would be nice to simply work in Pro Tools with the, ahem, RTAS version of VI.

Thanks,
Jack

I've already ordered the 2 bay internal RAID 0,1 Module, with 2 X 500GB.(and it ain't cheap!) So if you have bad news don't say it. Just pretend it's an excellent deal! [:D]

Jack -- your seup is similar in some ways to mine. I use an internal SATA for audio too. Sounds like from what Christian said, as long as the library is split into orchestral sections, JBOD will be the way to go (as I'm doing now).

I'm not sure we'll ever see an RTAS version of the VSL VI, though - it might be a wrapper (hope not). That's the reason I'm thinking of setting up my new Quad without ProTools (I use DP as a front-end to PT). Hope we can find out more specifics about VSL's plan's for RTAS soon -- I'd like to get moving on my setup.

Guy,

It's an excellent deal. Spot on.


Gary,

So you will end up with two G5's - one for Pro Tools and one for DP? Add MIR to that and you have a ton of hardware. How are you going to get audio back and forth between DP and PT? Lightpipe through an RME Fireface or bounce and send files?

The dual core, dual processor cpu's look great but I haven't seen enough to persuade me to get one now. Sometimes I actually like to use this stuff instead of spending all my time trying to make it work together.

I'm still holding out hope for RTAS. As much as I like Logic it would be nice to have one platform instead of two, especially the one that is definitely more stable. My thoughts on this are that there is a purely financial reason VSL would develop RTAS. There's all those individuals and companies that own Pro Tools who perfectly fit in with VSL's customer demographics. I think I understand why they didn't develop it first - they had their hands full and they needed to get out new product quickly to get a substancial boost in income and also to satisfy their current customer base first. After all, it never worked within Pro Tools to begin with. And maybe Digidesign got a little sticky with them. The issue may not be on VSL's side.

VSL did say that they plan to have it working sometime in the future. I'll just hold that thought in a positive mode. Besides, much to VSL's credit they run in 'silent' mode until a product is just about ready to ship.

Best regards,
Jack

Jack -- it's my intention to do everything on a single Mac (the Quad). DP running DAE, as I've always done. For me, things are very simple with one computer. I had 3 G5s at one point for large projects. Now with the SATA setup and other tweaks, I'm down to 2. A buffer of 1024 with DP under DAE feels like a 256 or 512 buffer running DP natively under MAS. So you can get a lot of VI tracks going with barely noticeable latency, preserving CPU horsepower. I will keep the other G5 as a slave though, use it as needed.

@Jack Weaver said:

Guy,

It's an excellent deal. Spot on.


Jack

Thanks man! I'm really glad you think so. [[[:D]]] [[[:D]]] [[[:D]]]

Have a little problem here...

I bought a sata system, but I can't seem to extract the content of the DVD ROM that came with it. It contains 2 files: Firmware and RaidGuide. I presume they are vital for it to work?

2nd question: the wire with the 10 tiny holes, there's that connection in the back of the sata module but not in the back panel of my G5 Quad. Are they also suppose to connect with that wire?

@Guy said:

Have a little problem here...

I bought a sata system, but I can't seem to extract the content of the DVD ROM that came with it. It contains 2 files: Firmware and RaidGuide. I presume they are vital for it to work?

2nd question: the wire with the 10 tiny holes, there's that connection in the back of the sata module but not in the back panel of my G5 Quad. Are they also suppose to connect with that wire?

I'm not sure what type of SATA setup you have, but there are no PCI-Express cards available for the Quad that will allow you to connect external SATA drives yet. A month or 2 away, from Sonnet and others. If I'm understanding your question, you can't connect them to anything on the back of a G5 (you need to install the PCIe SATA card. There's a card from Highpoint, but it's only for extra internally mounted drives.

guy, i'd assume it is this device - the firmware is just attached for service purposes, before you update firmware it's always a good idea to look on the website of the manufacturer for a newer version, although this should not be neccessary at first.

the *raid guide* is possibly a raid monitoring software - for this purpose you had to connect the system via a serial port - nothing like that on a mac since years ... i'd say: both pieces software are windows only ....

the display should tell you in which raid-mode the system is configured by default - make yourself familiar with the buttons on the front and change the raid-type if needed. after power-up the device should start configuring by it's own.

regarding the connection: well, the quick solution would be to take one of the PCIe-slot caps out and connect it with the sATA-wire to the free internal sATA-port of your G5.
once the selfconfiguring process of the device is finished, you should see it in your disk utility ready for formatting

christian

I may be wrong here as I'm no expert!

If you are using an external enclosure that presents 2 or more drives through a single eSATA connection there are 2 things to consider. Firstly there is a data limit by all drives having to pass data via a single eSATA therefore with SATA 1 the theoretical limit is 150MB's per second regardless of drives whereas if the enclosure provides seperate eSATA connections to your host card the SATA limits (SATA 1 150MB/ SATA 2 300MB) apply to each drive. In this case the only limiting factor will be the transfer rates of the drives thus potentially much higher transfer rates will be achieved in a Raid 0.

The 2nd issue is will 2 drives connected on a single eSATA be available to the Mac for software raid solutions or formatting? - I'm not sure they will be so perhaps special software is required - I saw from the link Christian provided that that particular enclosure had specific software (windows only) so how this works with a G5 it would be sensible to check.

G5's internal SATA connector might require an eSATA-SATA lead as the internal connections are of a different profile.

Julian

Thanks cristian, garylionelli and Julian.

christian, that is very very close! You a verrry smarrrt man!
It's SR 3600 http://www.stardom.com.tw/main_e.htm


Now I bought it from the Mac shop where I bought the Quad, so it was understood they would work well together. Unfortunately, a few hours later after I had left he closed his shop until Jan 3rd. Just great!!! But I assume it's not a major thing.

I at least want to be sure of the connections,

I'm not sure if these are standard names for the cables but this is what's in the back of the module:

RS232 Cable(10 little holes)
USB2.0
1394-B "Out" and "In"

the specific model is SR3600-2S-WB

So what would be the connection going to my Quad? I'll understand better this way...

If I could get this, that would be a wonderful christmas present! [:D]

Hi Guy,

couldn't see a SR 3600-2S-WB only a 3500 version. Looks like you've got yourself a USB2/firewire 400/800 device. If that is the case ignore USB 2 (too slow) and get a firewire 800 (1394-B) connector to connect directly to your G5. Check your G5 instructions to locate and recognise the FW 800 connects (they should be the same as the ones on the external enclosure).

This won't be the same level of speed as a SATA interface but will be compatible with your Mac without having to install extra drivers. If you have 2 discs in the enclosure they will either present themselves as 2 seperate discs or if the enclosure is running a hardware raid (like the Lacies do) then it will be a single disc.

Julian.