Recommended RAID Config - 5 Disk

somewhatdamaged · 13 Sep 2007 at 09:46

Hi Guys,

I have 5 x 500GB Samsung Spinpoint SATA2 HDDs connected to an LSI Hardware RAID controller (8 Port)

My PC will be used mainly for games, but also storing MP3s and videos which I would like to be quite secure / redundant. What RAID config would you recommend?

I considered RAID 5 but worry that the write speed might not be very good, and I also considered RAID10 but would not be able to use one of the disks – it would have to be standalone as it would use 4 disks.

Also considered a 3 disk stripe and a 2 disk mirror, but 1.5TB seems a lot of space to risk on RAID0!

Any ideas?

Thanks

rpstewart · 13 Sep 2007 at 10:47

Do you have the full model of the controller? If it's one of the PCIe 8x ones then don't worry about the RAID5 write speed, it should be very good.

The bottom line is what do you want the PC to do?

If you do any disk intensive stuff then you need to consider the impact of I/O contention - if you put all five disks into a single array then you in effect only have a single set of read/write heads so any simultaneous read / write operations (copying, archive extraction, video editing etc) will be affected.

Remember that RAID will only give you hardware redundancy, it's not a backup. If you delete a file or it becomes corrupted for some reason it's gone. If you don't already have a backup plan in place then you need to consider that too.

There will be a layout that suits what you need so if you could answer the questions above I'll have a think.

somewhatdamaged · 13 Sep 2007 at 10:53

Hiya,

This is the model :-

LSI MegaRAID SAS 8308ELP (PCI-E x4)

I can backup anything really critical to another machine via gigabit so i guess data redundancy is not 'that' important. I supposed if all i really do is play games then i should go for maximum performance? I did consider a 5 disk stripe, but i was paranoid that the chance of a disk dying was pretty high, and all being the same brand would not help either!!

Cheers

PS - on a side note, i have just been on your website and your pictures are quite fantastic. I think i will order some for my wife. Do you do larger size prints (for framing and going on my front room wall) ?

rpstewart · 13 Sep 2007 at 11:05

That card has the same XOR engine (Intel IOP333) as the Areca 1220/1230 range of cards so the RAID5 performance will be on a par with the Areca, ie very good!

What OS are you planning on using? I've found that Vista doesn't hit the swapfile anything like as hard as XP (although 8Gb of RAM does help :cool:

) so with Vista I'd be tempted to go with a 5 disk RAID5 array and backup to the other machine over the LAN. For XP you might see a benefit from having a 4 disk RAID5 array and a single drive for the swapfile and backups.

somewhatdamaged said:
PS - on a side note, i have just been on your website and your pictures are quite fantastic. I think i will order some for my wife. Do you do larger size prints (for framing and going on my front room wall) ?

Thanks! Sizes up to 30" x 20", drop me an email.

somewhatdamaged · 13 Sep 2007 at 11:09

Hi,

I will be using Windows Vista x64 Home Premium

I am waiting for 3 of my disks to be RMA'd back to me (should arrive Monday)

In the meantime i tried a 2 disk stripe and the performance was fantastic, it was quicker than nearly every onboard RAID stripe i had seen in the benchmark part of this forum

I really hope the RAID5 performance will be good !

rpstewart · 13 Sep 2007 at 11:21

somewhatdamaged said:
I really hope the RAID5 performance will be good !

It should be, RAID5 normally gives read rates about the same as a RAID0 array with one less disk. Mind you if it ends up beating my 200MB/s average I'll not be happy - I can't afford any quicker disks at the moment!

somewhatdamaged · 13 Sep 2007 at 11:37

I'll let you know when the disks arrive!

Mr Jack · 13 Sep 2007 at 12:50

I'd go RAID 5 - it'll give really pretty good read/write speeds and you get redundancy. Your access speeds will suffer though.

RaiderX · 13 Sep 2007 at 12:56

raid0 would be very quick with that many drives, i would say raid10 for the speed and backup

Mr Jack · 13 Sep 2007 at 13:02

RaiderX said:
raid0 would be very quick with that many drives, i would say raid10 for the speed and backup

Raid 10 needs an even number of drives, and is significantly slower than RAID 5; although it does offer a bit more redundancy. RAID 6 offers the same level of redundancy, could use all 5 drives and would be faster than RAID 10 (assuming you're RAID controller supports RAID 6, of course). But me, I'd go with RAID 5.