To RAID or not to RAID

vbimport

#1

I recently purchased a computer for donation to a Non-profit Music Association in the Denver area. It will be used by the sound engineer for recording which requires a good bit of horsepower and speed when multiple tracks of music are being processed. The computer has these basic specs:

PhenomX4 1.8GHz (Not the fastest,but they’ve been on a P4)
GeoForce 6150SE nForce Chipset
6GB RAM (DDR2 SDRAM)
We had planned on one HD to house the O.S. and Recording Software, and a second for Storage.

The computer specs stated 1T SATA 3G, 7,200 rpm and I had been researching the merits of adding one 10,000 rpm drive, vs two 7,200 rpm dives in a RAID configuration. On a second look at the specs the 1T comes as two 500GB 7,200 rpm drives.

So my question is what to do now. Would it be fastest to set the two drives up in a RAID and run everything off of them, or would adding a smaller 10,000 rpm HD to handle the processing have any advantages? If not, would running the two in a RAID be speedier than using one HD for operations and one for storage. I guess my quandry is partly rpm vs RAID, and partly whether separating processing and storage onto different drives makes any difference.

I’m sure this topic gets beaten to death, but my search lead me to this forum and I’ve learned a lot in reading some threads, and it’s apparent that there is a high level of expertise gathered here. Any advice would be greatly appreciated, and I’ll say thanks in advance to those who share there time and knowledge here with the less informed.


#2

Don’t cross post. Which is posting 2 identical posts, it’s against forum rules.
as for the setup, not sure.


#3

My mistake, I had posted the question under General Computer Hardware and later saw the forum specific to Hard Drives and copied the question there. I’ ve not been able to delete the first post.
Kwaag


#4

It depends if you intend to use 24bit recording or 16bit.
If it’s 16 bit then i would have 2 HDD non RAID. A 10,000 RPM as the OS HDD and local cache for the recorded tracks, then use a larger 7200rpm drive for backup of these tracks and the finished mix. With that setup you should be able to manage around 16 tracks.

If it’s 24bit then you will always be trading off sequential read/write speed with latency (HDD access times). RAID can’t solve that, in fact RAID adds to latency. To get more than say 10 tracks in 24bit, you really need an SSD, and that will add to the cost by quite a lot.

My own setup is 24bit, with an Intel i5 @3.8Ghz and a OCZ Vertex 120GB SSD, plus a 7200rpm 1TB drive for storage.
Windows 7 running Steinberg Cubase.
With this setup i haven’t reached a track limit, yet. :slight_smile: The max tracks i have recorded so far is 21. The reason SSD does so well is its low latency which is around 0.1ms compared to even the fastest 10,000 rpm HDD which is around 4.5ms.


#5

[QUOTE=kwaag;2492264]My mistake, I had posted the question under General Computer Hardware (…) I’ ve not been able to delete the first post.[/QUOTE]Fixed. :slight_smile:


#6

Uhm… what?
Are you trying to say that you need a SSD for transferring 10 * 0.25mbyte/s ((44100224))/1000/8/1024) even if you double the sample rate you get a measly 5mbyte/s. Which HDD today can’t cope with that?
You’re probably better off running a separate HDD for the OS / Application and a RAID for recording (although I highly doubt its needed). Afaik Cubase is much more cpu dependent and sound card interface (ASIO etc) than picky on transfer rates.
//Danne


#7

DiiZZy with all due respect, you haven’t a clue what your talking about.
For starters, 24bit pro standard audio recording is normally 192,000bps x 2 for a 3 minute recording that’s over 200MB of data for each track.
If you happen to be recording your 10th track, that means 9 other tracks have to be read while the 10th is recorded. The head on an HDD can only be in one place at a time, 10x 4.5ms (best case scenario) = 45ms latency, long past the stage that the human ear can detect. Lucky the data is cached to a certain extent, but there is a limit before the whole system just has to much latency.
End of story, go check it out instead of trying to discount what other people say.
Multi track recording has very little to do with sequential read/write speed, its all about latency.


#8

Just for fun I did unscientific test which shows that at least this is old HDD (Hitachi T7K500 320Gb) managed to do 10 simultaneous writes @ 2.9mbyte/s (that’s more than twice as much bandwidth as 24-bit 192kHz and I assume you mean hz not bps) which wont introduce latency as data is read faster than it’s played (caching/read-ahead) unless it chokes on the way for some reason which will give you skipping audio. It surely wont cope 20 tracks at once tough…
//Danne


#9

Dee and DiZzy, thanks much for your responses. They differ, as often happens, but there’s more to learn from debates than agreement.
With limited funds, it seems wisest to start with what we’ve got and use the computers two stock drives, separating one for processing and one for storage. If he (Brian, the recording engineer) has problems we’ll move up a step, maybe a 10,000 rpm HD. SSD clearly has a speed advantage, but the cost is high enough we’d want to be sure the HD was an obstacle before going that route.
If you can believe it, Brian is currently on a P4, 1G RAM, and two 300GB HDs. I had latency problems with a better rig than that just recoding at home. I think he uses his external equipment to advantage, but it still bogggles me. His current problems aren’t so much in processing, but in system problems (his midi settings are resetting and other matters that I don’t understand).
So this computer, while not a powerhouse, will be a magnitude above what he has now.
He does have 24 chanels, but says he rarely exceeds 16 tracks. The bulk of his work is acoustic music with a limited number of instruments and may stay under the 10 tracks as tried in your test much of the time. The proof is in the processing so we’ll see how it goes.
Kwaag


#10

[B]Kwaag[/B], that seems like a sensible way to proceed, and good luck.
Please let us know how you get on with the new rig.


#11

Thanks Dee, the computer was delivered today so I can start setting it up and I’ll let you know how it goes.
You seem to be well versed in computers and recording. I’d like to throw another question to you. Brian is using a MOTU 424 interface, currently into a PCI card (proprietary audio wrie connection). There is a PCIe card available for about $250. Do you think upgrading the card will have any advantage. I don’t know if the faster transfer speed of the card can be used by the older Motu device. In other words is the card the limiting factor. I called MOTU, but they didn’t seem all that knowledgeable. I hope I’m not imposing, but if you have any advice, once again it would be greatly appreciated. Kwaag


#12

I have heard a lot of good things about the MOTU 424 cards, although i have never used one myself.
Until very recently i used a couple of Yamaha 2416 cards which were PCI and had no problems with latency.
I recently upgraded to a RME HDSPe AIO 38-channel card, its PCIe, although i’m pretty sure i haven’t got anywhere near using all the PCIe bandwidth.
I’d keep the MOTU 424 and see how it runs on the new system, and take it from there.
I think PCI has a bandwidth of around 100MBytes per second which should be more than enough, PCIe x1 has 250MBytes per second. PCIe2 x1 500MBytes per second.


#13

The latency isn’t in the interface (PCI), it’s either in the driver itself or lack of processing power of course some hardware can increase latency somewhat or give spikes given how they’re designed.
//Danne


#14

All the cards mentioned use the their own hardware and should do all I/O internally, there should be no problem with latency with any of these cards. The RME HDSPe is rated at 0.7ms, for example.
They can’t be compared to motherboard onboard sound, or sound cards such as SB or Sonar, which generally have crap and bug ridden ASIO drivers.


#15

Thanks to you both. You made it a lot clearer than the MOTU folks. We’ll use the PCI and save some dough. I’ll bring the computer to the studio tomorrow and we’ll start setting it up. I suppose it will be a few days before we put it to the test, but I’ll let you know how it goes.
It has been my good fortune to find this forum and get your expert help.
Kwaag