Best Results Have OS on Seperate HDD?

[Primary B]

Read a thread on frame dropping here but kinda turned into an Sata-SCSI discussion. Great timing for me. I'm new to this and I want to put my Analog tape to DVDR-. I have 2 Seagate 160G SATA HDD's coming tommorrow or Fri setting up in a raid o config. I already have 1 200G installed on IDE #3 on a MSI MoBo. I read it is best to keep your Operating Systems (Home XP in my case) on a seperate HDD. Some questions,
1 Install Video Capture, editing Programs and storage for video on the raid set-up and OS on the IDE HDD or all programs on IDE HDD and video storage on Riad O?
When I intially ordered these HDD's my idea was to put everything on the Raid set-up and take advantage of the speed and use the IDE HDD for back-up and storage. Since I going to have to reformat everything now would be the time to do this right. I also do some DVD backing up so does anyone have any advice? Thank's in advance.
PrimaryB

[Perro Grande]

For any process that is drive-intensive, I generally recommend keeping the OS and Applications on one drive, while using a different one for the working data. Ideally, it is also a good idea to have the windows pagefile on a different spindle (different physical drive) than the OS. Ideally, OS, Pagefile, and App Data should all be on different spindles.

That said, things must be thought through a bit differently when RAID enters the picture. A lot of the decisions you need to make are based on the way your particular RAID controller implements RAID 0. If it implements RAID0 via a simple overflow spanning operation, you'll get no particular speed increase and have no redundancy. If your controller implements raid 0 using byte or block striping, then you will gain performance increases (especially for larger reads and writes) but still have no redundancy.

If you're talking about RAID1 (mirroring), you'll get redundancy and *maybe* read performance increase, again depending on how your controller handles fetches to the physical drives.

That said, most "consumer" raid controllers are fairly simplistic in their implementations of the various available configurations, so your performance gains might not be as much as hoped for. If you're not gaining redundancy, I'd recommend against RAID in that case.

That said, if you're rebuilding everything and really want to use RAID, I'd put the OS and apps on the IDE drive, and your data on the RAID drives. Leave the pagefile on the IDE drive to reduce un-necessary hunting on the RAID set.

[jimmalenko]

Correct me if I'm wrong, but isn't the whole point of RAID is that it mirrors the contents to the second drive and so acts as a backup ?

EDIT: RAID (1) is according to the above poster.

If this is the case, I would put all programs and OS on your RAID, and leave your IDE for capture/DVD Backup.

[Perro Grande]

Technically, RAID 0 refers to spanning and does not include a redundant drive. Its kinda an oxymoron to have a non-redundant RAID system, but that is what Raid 0 is all about.

RAID 1 is mirroring.

When spanning and mirroring are combined, it is frequently called RAID 0+1 (sometimes RAID 10).

RAID levels 2-5 involve striping the data and the use of ECCs (error correcting codes) to provide redundancy. The subtleties of the various levels involve the size and nature of the stripe and the handling of the ECC (often inaccurately called 'parity') data.

Because of the way the data is spread out across the drives, different raid 'levels' are better at certain things than others. RAID 0+1 is excellent at maintaining performance when frequent small reads and writes are done. Likewise, RAID 3 or 4 is good for steady, large data reads (streaming video).

In this case, if he is using RAID 0, which is non redundant, any performance gains are dependant on how the controller manages the spanning of the two drives. He MIGHT be better off to just go with three separate volumes and scrap the raid 0 all together...

[jimmalenko]

Thankyou for that excellent summary Perro.

[redwudz]

I just keep video files on my RAID0. It does sometimes crash, but resets itself with no data loss. I have had one of the RAID drives fail and with that all data is lost. I keep the OS and programs on the boot drive. The video files on the RAID are just there temporarily, so if it dies, no big loss. I also use a backup drive for program files. RAID0 is not good for archiving, but great for speed.

[Perro Grande]

Yes -- RAID 0 *may* give you a performance increase -- it all depends on the controller.

In your case, Redwudz, it probably created the array by block striping the data across the drives. This WILL give you a nifty increase in speed, especially on larger transfers.

If, on the other hand, the controller just fills one drive and then flops on to the next, you'll get very little increase.

You can usually infer which method a controller uses. If the setup screen or the instructions are talking about block size or stripe size even when you're creating a RAID0 array, then you're probably in luck.

[Primary B]

Thanks guys. Perro, very informative. The raid controler on the MoBo is a Promise FastTrak378. The manual talks about doubling the sustained data transfer rate with striped arrays Which in this case with the Seagates would be 300MB's. I have the options of 0, 0+1 or 2 up to 4 HDD's. I can also select strip values for Raid 0 array. Once again thanks.

Primary B

[northcat_8]

I have 3 drives.

60 GB OS drive Primary IDE channel
120 GB capture/rip drive Secondary IDE channel
2-80 GB finishing drive - RAID Stripe 0 array.

60 GB WD:

Read: 7065 Kbyte/sec
Write: 8703 Kbyte/sec
Safe: 6358 Kbyte/sec

120 GB Maxtor Ultra 8 MB cache

Read: 30690 Kbyte/sec
Write: 31161 Kbyte/sec
Safe: 27621 Kbyte/sec

2 - 80 GB Maxtors in Stripe 0 RAID array

Read: 76424 Kbyte/sec
Write: 27338 Kbyte/sec
Safe: 24604 Kbyte/sec


My 60 GB is a quite a bit older than the Maxtor drives.

I capture just about everything to the 120 drive, the write is about the same for the 120 and RAID, but the read is much better from the RAID, so when I need a program to read the video, I want it read off of the RAID. So like when I back up a DVD, I rip to the 120, encode and output to the RAID, so that when Decrypter reads the ISO file the drive is more than capable of giving it the speed it wants.

Since I went with the RAID...I have not had dropped frame issues or any kind of issues related to a hard drive. I won't ever have a video system without RAID ever again.

On a side note, I also think because my video files are on the RAID drive and the program can read the file as fast as it wants to, is one major reason why I have never had any audio sync issues with any authoring program. Including, DVD Workshop and TDA. I think this because I had a file on my OS drive once, it was decent size and I did have an audio sync problem but only with that file. I moved it to my RAID drive, re-authored the DVD and the audio was in sync. (that was a DVD Workshop project)