Is this RAID good?

[Shalashashka]

I am building a professional video editing computer. Here are the specs:
Intel i7 950
Asus Rampage Extreme III
Nvidia gtx 580
24 GB RAM
1 Intel 128GB SSD
4 Hitachi Deskstar 1.5TB 7200 RPM sata drive in RAID 0
On board RAID controller Intel ICH8.

The RAID seems to be working but I want to make sure they will work perfect and fast for video playback. They must do seamless playback with uncompressed HD video. I ran HD Tach and it says 399.0 MB/s which seems fast, but there are some large spikes in the graph. Is that normal? I don't want it to drop frames in playback or anything. Ill attach an image of the HD tach results.

Any advice would be great!!

 

[mryoink]

4 Hitachi drives in RAID 0 sounds risky, any of those fail you lose the data. Just make sure you have a good backup solution in place. HDDs in general can be spikey as they search for random data.

 

[geofelt]

I suggest you try your critical app using a couple of different methods. A synthetic benchmark shows the maximum potential, and, is representative only if your app processes hard drive data the same way.
1) Raid-0
2) No raid at all.

If your playback app is written to read ahead data before it is needed for processing, then raid-0 will perform very well.
If not, then a simple hard drive may be better.

Let us know which works best for you.

If you are serious about raid, then a discrete raid card will perform much better, but a good one will be expensive.

 

[Shalashashka]

Thanks for the replies everyone. I just had a chance to play some HD files and it all runs good. I think the 24 GB of RAM helps alot. I am still not sure how it will perform under a big load as we have not started using this computer for work though. I am beginning to think the spikes in the HD tach graph are normal.

A discrete card would be nice, but they are upward of $700. I think the on board RAID will do what we need.

 

[tokencode]

I agree with Mr. Yoink, if you care about that data make sure you have a backup. Your array is 4 times more likely to fail than a single drive and if it goes you will lose all your data potentially.

 

[natx808]

1920 * 1080 = 2073600 number of pixels
2073600 * 24 = 49766400 24-bit color (16.7M colors)
49766400 * 60 = 2985984000 60 frames per second
2985984000 / 8 = 373248000 convert to bytes/sec
373248000 / 1024 = 364500 convert to KB/sec
364500 / 1024 = 355.957 convert to MB/sec

That isn't factoring in audio, btw. you're also very close to the limit of SataII (2.85 Gbps vs 3Gbps)

I would recommend for a "professional" rig that you get a PCI-E SAS 6.0 controller with 1 gig battery backed write cache and an array of 10 15k 300GB SAS drives in an external enclosure running Raid 10.

 

[Shalashashka]

So what youre saying is 355.957mb/sec is what is required for HD playback?
I am not concerned with data loss. The drives will only have captured, unedited footage. I would love to setup something like you suggest, natx808, but that would cost too much. Really all I am asking is if my current RAID is configured right. The spikes in the graph concerned me and prompted this forum post.

 

[geofelt]

Thanks for the replies everyone. I just had a chance to play some HD files and it all runs good. I think the 24 GB of RAM helps alot. I am still not sure how it will perform under a big load as we have not started using this computer for work though. I am beginning to think the spikes in the HD tach graph are normal.

A discrete card would be nice, but they are upward of $700. I think the on board RAID will do what we need.

Don't try to solve a problem you don't have.
If your workload runs well, you are done.

If you are concerned about a heavy workload, test it. Using your app, and your data.
Synthetic benchmarks are tests using someone else's program and data that is convenient for them.
It is an indicator only. What you care about is how your workload will run.

 

[FireWire2]

Don't try to solve a problem you don't have.
If your workload runs well, you are done.

...

2nd to that - Bench test only tells you half of the story!

natx808

Most of the 1080p(s) are use VBR, and bitrate is based on the codec also... Your calculation is way overboard. LOL