Storage 4xHDD Raid 0 Performance

Hi folks,

having recently bought a home server, I was going to shunt all the important data onto that.

I've got an ASUS P5B motherboard with a Q6600 CPU and a GTX260 graphics card.

Currently in the machine I have 2x1TB Samsung F3 HDD set up in a Raid 0 (with an external backup)

I've also got 4 x 250GB Hitachi HDD sitting in a drawer from an earlier machine. I've been thinking about re-building the machine with the 4 250GB HDD in a Raid 0 configuration.

Am I going to get twice the performance? I can't make up my mind whether it's worth doing or not given the time required to rebuild the machine.

I have a feeling that the HDD is the main bottleneck in performance in the machine, or am I dreaming.

I mainly use the machine for playing Civ/CoH, simulation number crunching and the occasional multimedia ripping.

I do plan to completely upgrade the machine next year.

Any advice?

 

First of all, no, you won't get twice the performance. A decent SSD will smoke those hard drives for a desktop.

Secondly, it's quite insane to put four drives in RAID 0 as you're quadrupling your chances of disk failure. Remember, if one drive dies, everything is lost.

If you'll be getting a new system soon, you might as well wait out and pick up an SSD which will be faster and cheaper than the ones currently available.

 

Use Raid 5 if you've got 4 disks. You'll get roughly 750 GB usable and have disk failure redundancy.

 

raid 0 is hard to justify really

its headache and you dont really get much of a boost unless your doing soemthing very specific

also old 250GB HDD are most likely quite slow to start with so a nice fast modern drive would be better anyway.

oh and you NEVER want to raid 0 in a home server EVER. redundancy and backup are the most important things for servers not speed unless its a large business environment where data throughput is important.

 

Thanks for the input. The HDD are for my desktop. The home server would be Raid 1 on some eco drives.

So, there would be nothing meaningful data wise on the desktop. That's what made my think about Raid 0.

Interestingly, I do have an SSD (Crucial 128GB) and it's only about 20 per cent faster than a 2 disk Raid 0.

I had a rocket card but it's not compatable with this board. Indeed I can't find a Sata3 card that is compatable.

Mmm back to the drawing board.

 

20% faster... In what ? Sequential read ? Do you really do that often ? Or you really use your computer, where 4k writes and access time are lot more important. And in those stats, we are talking about 10-20x performance of one SSD vs RAID0.

 

why does your board not support the rocket ?

all it requires is a PCI-e x1 slot

 

It's interesting you say that about requiring a x1 socket. You actually need a x4 socket, it seems to get the throughput.

There's something in the asus board that doesn't cope with this for the Rocket, as confirmed by Asus.

 

Fair point about the 4k blocks. Can you recommend a good benchmark tool to measure it?

 

Is your life made up of benchmarks?

Iometer or Crystal disk are good for measuring random performance.

Even a slow SSD is going to be much faster in application loading, OS operations and booting than a Raid configuration will be with spinning disks.

My vertex 60gb drive is at least twice as fast in loading Win7 and applications than my 500GB Samsung f3. At least. For some of the smaller file operations it is noticably several times faster (Adobe elements 2 loads in about 12s off my F3, in about 4s off my SSD).

 

I'm an engineer, what can I say!

No matter how much I want it to, I'm not getting an order of magnitude performance improvement over the HDD.

I'm thinking it's 'cos I'm limited to Sata 2 speeds with this mobo.

 

Random, not sequential performance is what's really important on a desktop system. And SSDs definitely offer several orders of magnitude of improvements over HDDs in this regard.

 

the 620 is a x1 slot which has 2 6Gbps SATA ports

the 640 has a x4 slot which has 4 6Gbps SATA ports

although the bandwidth is only 4Gbps from a x1 so yeah whats the point lol ? seems a bit daft

 

Yeah, found that one out the hard way!

 

At most you'll nearly get quad performance of your 2 slower disks, like they say it's the 4kb random reads and writes that slow physical disks down and no amount of raid is going to speed those up much.

If you really want to do this, your best bet is to raid 0 each of your pairs of identical disks, then use Windows to stripe those pairs together (with dynamic disks), that way you'll have all the available disk space.

Probably worth doing some extensive benchmarking first so you can match up the speeds of your disks.

As I'm sure you're aware the closer to the beginning of the disk, the faster the access, but if the last 250GB of your TB disks are still faster than your 250GB disks then it won't make any difference to the raid partition in (terms of speed) where you put it on the TB disks, so you might as well put it at the end so you can take advantage of the faster part of TB disks (you can do this with windows disk manager) . That way the speed will be more evenly balanced out.

 

Have you considered RAID 10?

 

Have you considered that your network is the bottleneck anyway?

 

Thanks folks, I think, given the good advice I'll wait till I upgrade the motherboard and the go to an SSD with a fast HDD.

I would be messing about for limited returns with the Raid.

Thanks everyonre!

 

Yep.

Why not raid 5 with another 1tb disk? Or 0+1?

I have a raid 5 server and my network is the limiting factor, plus samba overheads. It didn't need a quad either... but if ones spare, it'd probably be in there. lol

 

^^ Yup, I can easily pull 100MB/sec from my server over gigabit ethernet.