RAID 5 Performance as Main Drive

Y

y13

n00b
Joined
Jul 15, 2008
Messages
8
I have several 750GB HDs and planning to RAID them. If I do a RAID 5 and use that as my main drive would I suffer any performance or any other issues. I know the read will be slower than doing a RAID 0 but if do a RAID 5 over at least 4 drives can this be compensated? What number of drives would be the best to use or is it just best to do a RAID 0 with one set and RAID 5 the leftovers?

I'd really appreciate the help. Thx.
 
Others can explain it better than I, but RAID 5 suffers from inherent write speed deficiencies due to the parity calculations required. There's also computation overhead that will either take up some CPU power (although not huge by todays standards), or require an expensive hardware controller.
If you want speed and reliability, look at a RAID10. It requires 4 disks and gives you the capacity of 2, but gives you speed benefits of RAID0, but with mirroring.
 
Thanks for the info. If the write is not a big issue and the reading of files would be, can I still go for the RAID 5 because I am trying to keep the space if possible rather than losing another drive to RAID10?
 
y13 said:
I have several 750GB HDs and planning to RAID them. If I do a RAID 5 and use that as my main drive would I suffer any performance or any other issues. I know the read will be slower than doing a RAID 0 but if do a RAID 5 over at least 4 drives can this be compensated? What number of drives would be the best to use or is it just best to do a RAID 0 with one set and RAID 5 the leftovers?

I'd really appreciate the help. Thx.
Click to expand...

Ok well first off how many drives do you have?
Are you talking about Raid5 vs. Single drive performance?
What raid card do you have or are you using onboard controller?
 
nitrobass24- I currently have 4 or 5 but I know someone who can give me some of his if I ask. As far as I am concerned at the moment I am sticking with about 4 or 5 right now.

I plan to use an onboard controller if at all possible. Last resort is I am going to buy a controller but I don't really wanna do that right now if possible.

Here is what I know in terms of performance. I know RAID 0 works much better in reads and writes compared to a single drive without losing space. RAID 5 can get much better reads but writes are slower because its writing to an extra drive which I lose in usable space. In comparison to doing a RAID 0 with two disc and a RAID 5 say in 4 disc, would there be a great performance difference? Will there be a better performance if I add an extra disc (or 2 or 3...) to the RAID 5 array or not much at all?

The major use of this PC is going to be for HD playback, storage, and possible streaming and editing from time to time (gaming rarely). I assumed that getting better reads will give make my HD playback smoother therefore I thought RAID 5 would be the way to go while having some sort of security.

Sorry for all of the questions but in general, will using RAID 5 as an O/S in addition to what I will be using this system for be sufficient while not holding me back a whole lot in performance?
 
If you are using the onboard controller I would not use a raid5 for the system drive...due to the parity calculations you will notice a slow in your computer during writes to the array. It seems to me that your looking for something that is fast, but you would like some data security you sound like a good candidate for a RAID10 or 0+1 speed and redundancy. Definitely would not do raid5 without a dedicated controller.
 
RAID5 is more appropriate for long-term storage solutions with some kind of redundancy, I personally wouldn't recommend RAID5 for an OS partition because of the processor overhead in regards to parity calculations. RAID5 is preferably on a hardware solution, with dedicated processors and memory optimized for disk I/O, but those tend to be pricey. Another solution would be to utilize RAID 10 or 0+1 for speed and redundancy, but the disk overhead is 50%.

For your needs (HD playback and other read-intensive tasks), software-based RAID5 would be a possibility that's not outside the realm of possibility, but it's preferable to use a separate disk for an OS and keep the RAID5 partition free of Windows/OS files. Of course, software RAID5 is slower and requires more processor usage to calculate parity while writing onto the disks, and would also tie you down to the OS you are using.
 
I recommend a dell perc 5/i. They can be had for around $100-160 on ebay or here is where i got mine
Link
its a 8 port hardware sas controller. You can find the cables you will need to convert sas to sata here
Link
and here
Link
It made a massive difference in my vista 64 experience. I went from 4 250 gig sata drives in non raid to 7 drive raid 5 (+1 hotspare) raid array. average reads of around 250 MB/s and Writes about 150-175 MB/s and that's with vista 64 native drivers no manufacture reference drivers. You can get the whole setup including the cables for around $150. It is a 8 port hardware raid controller for under 200. That is a outstanding value in my book. It will do either sas or sata.

Edit: you will also need a pci bracket for it
Here
 
Thanks a lot for the info. Looks like the only time that it would be worth it to do a RAID 5 with my drives is to make it into some type of storage server.

Just for curiosity sake if I use the onboard controller, will RAID0 or RAID1 performance suffer to to clock cycles being used like RAID 5 or any other problem? Should I just stick to a hardware controller for any type of RAID being used?
 
no, Raid 1/0 does not use any kind of parity checks, which means it uses very little cpu overhead. I've been using Raid 0 for the past 3 years for my OS drive, and I'll never go back to a single drive again.
 
djgizmo said:
no, Raid 1/0 does not use any kind of parity checks, which means it uses very little cpu overhead. I've been using Raid 0 for the past 3 years for my OS drive, and I'll never go back to a single drive again.
Click to expand...

This thread has pretty much answered a lot of my questions. Thanks.
 
y13,
I have been impressed with my Areca 1210 card and RAID 5 setup using 3 drives with a hotspare.
It was night and day for me when I had a single seagate drive and I installed 4 WD 6400AAKS. It was like a whole different world. Things are super fast. Again take this with a grain of salt though. My setup has improved things for MY PC NEEDS. My game load times and other things I do have shown improvement.

After I had did research on RAID software/hardware i figured I never wanted to depend on on-board RAID. I'm glad I have made the choice I made and remember with anyone route you take. Backup your data and don't depend on the RAID to save you.
 
You must log in or register to reply here.
Back
Top