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How many drives for raid 0?

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Hi,

I'm a newb and have only been using single drives for years. I need some questions answered about raid 0.

Just how many drives can you put together in raid 0 on the motherboard chipset( X58 )? Or seperate raid controller?

Is the motherboard raid good enough for everyday tasks/gaming or do I need to buy a controller?

One last thing...would it be better in terms of performance/price to buy, say, 4 cheap drives or 2 of the best drives ( think raptor ) for raid 0?

I'm going to be building a new computer soon and I'm still on the fence as to which way to go for storage. Mainly going to be using the new computer for games and lite stuff. Data safety is not a issue. ( dont need raid 10 or NAS )

Thanks

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Hi,

I'm a newb and have only been using single drives for years. I need some questions answered about raid 0.

Just how many drives can you put together in raid 0 on the motherboard chipset( X58 )? Or seperate raid controller?

Is the motherboard raid good enough for everyday tasks/gaming or do I need to buy a controller?

One last thing...would it be better in terms of performance/price to buy, say, 4 cheap drives or 2 of the best drives ( think raptor ) for raid 0?

I'm going to be building a new computer soon and I'm still on the fence as to which way to go for storage. Mainly going to be using the new computer for games and lite stuff. Data safety is not a issue. ( dont need raid 10 or NAS )

Thanks

MB Sata ports are usually perfect for RAID 0, 1, 10 conf with 4-6 drives max

If you are looking for sequential transfer throughput: the more disk you have in raid 0, the better it is

If you are looking for direct io throughput: the faster rpm your disk are, the better it is (SSD rules this direct io world)

==> As I have no idea (neither time to learn) of the kind of io of your favorite games, I can not help more

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raid 0 is not good. you want it for imaginary reasons.

That's the most quotable thing I have heard all day.

Thanks Loomy =)

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What you buy and use is entirely dependent on you dataset and application...

Tell us that, and able we might be forth with knowledge. (Sorry for the bad Yoda line).

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RAID0, like all striping RAID, also increases the IOps, not only the maximum sequential throughput in MB/s.

The problem is that on Windows, you end up having a filesystem on the RAID0 volume that is not aligned with the striping blocks. This is due to the way Windows partitions and is not easily corrected. The result is that many of the potential of parallellism goes to waste due to two disks being needed for 1 I/O transaction, whereas you want 1 I/O to be handled by 1 disk so the other disks can take other I/O in the mean time. With a perfect alignment, most often found on Linux and BSD/UNIX families, you can boost Random IOps performance considerably:

Single drive
concurrency Performance in I/O's per sec. average
1		   106 106 107				   106
4		   106 106 106				   106
16		  116 116 116				   116
32		  127 125 126				   126
128		 151 151 150				   150
256		 156 156 157				   156

geom_stripe (RAID0) with 4 drives - 128KiB stripe
concurrency Performance in I/O's per sec. average
1		   173 173 173				   173
4		   270 270 270				   270
16		  338 338 338				   338
32		  370 370 370				   370
128		 444 434 434				   437
256		 465 465 465				   465

Analysis: performance increase ranging from 63% to 300%.

But you won't see any of that when using Windows without specifically crafting the filesystem to be perfectly aligned. Aside from that, if the topic starter wants performance for his desktop, i think an SSD drive might be the best choice, given you can justify the cost and settle for limited space to store your OS/Apps/Games on.

A nice and kinda cheap SSD is OCZ CoreV2 60GB or 120GB. These have very nice performance as well, just not as good as Intel X25-M SSD which is currently too pricey.

You can put SSD's in RAID0 without much risk, since SSD's don't just fail they have a predictable lifespan and even when failed you should still be able to read the data, just not write to it.

Just know that RAID0 does not improve gaming loading times alot, and certainly not the framerate. Games are too badly programmed to utilize performance potential, when loading data from disk.

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From what I've seen, you usually get a bigger boost with one very fast drive than with two cheap drives in RAID 0. For example, a single VelociRaptor will normally be quicker than two 150 GB Raptors (or four 74 GB Raptors, depending on the test) in RAID 0.

With spinning disks, there is often more to be gained by splitting your concurrently accessed datasets across two independent disks rather than trying to access two (or more) different parts of the same RAID array at the same time.

With SSD's, there's less penalty accessing separate datasets at the same time, because the access time is so much shorter. So there's no good reason not to run them in RAID 0, though again, performance differences between models can be substantial (for example the new Intel X25-M SSDs vs. just about every other MLC based SSD out there, and even some SLC based models).

So if you've got enough for one Intel or two OCZ Core SSDs in RAID 0, I'd pick the Intel.

Theory aside, if your budget allows, I'd pick an Intel X25-M SSD for your OS, apps and games, and a regular spinning hard drive (if you need the space) for bulk storage, backups of your SSD, media collections, etc. Store documents and other user data in a separate partition from your OS, and keep backups (that aren't stored in or next to your PC) of whatever you can't easily replace.

If your budget doesn't stretch to that, one fast drive (VelociRaptor?) and one big drive if you need more space makes more sense to me than RAID.

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raid 0 is not good. you want it for imaginary reasons.

SSD will probably be soon used in raid 0 as you won't expect a "head crash" and you can watch the SMART data safely (Of course, you do have a backup for those 0.0001% "century accident")

I am expecting next gen controllers to allow for raid 0 "hot plug" replacement (detect SMART problem -> mirror the drive using a spare -> remove the "bad" drive)

RAID0, like all striping RAID, also increases the IOps, not only the maximum sequential throughput in MB/s.

The problem is that on Windows, you end up having a filesystem on the RAID0 volume that is not aligned with the striping blocks. This is due to the way Windows partitions and is not easily corrected. The result is that many of the potential of parallellism goes to waste due to two disks being needed for 1 I/O transaction, whereas you want 1 I/O to be handled by 1 disk so the other disks can take other I/O in the mean time. With a perfect alignment, most often found on Linux and BSD/UNIX families, you can boost Random IOps performance considerably:

I strongly agree to alignment benefits and it will enhance the IOPS for the parallel io of a DBMS...but the io latency remains based on your drives rpm...and I think games are the kind of sequential apps that can suffer from this io latency. You are correct on SSD, that may help.

A nice and kinda cheap SSD is OCZ CoreV2 60GB or 120GB. These have very nice performance as well, just not as good as Intel X25-M SSD which is currently too pricey.

Not sure I will ever buy a SSD with a JMicron 602 controller (and the huge write latency occasional problem) on it...and I thought OCZ was build with one...

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The OCZ Core V2 is said to have corrected this extremely long write latency. Though i do not have clear confirmation, anyone considered buying an SSD is wise to checkout all relevant reviews and comparisons. If this is fixed, it should prove a good value for money, put alot of them in RAID0 on an intel ICHxR with write caching enabled (default is disabled) and the first X MB you write will slide into your RAM so you won't notice any slowdown in regular operation except for large writes but those the SSDs do pretty well.

Its the random writes that hurts, because the SSD has restrictions when writing to small parts in the memory, it must first be read, then erased, then re-programmed for a full cell block, so writing 4KB might mean the SSD has to process over 2MB, you can see this is going to hurt performance. Still, SSDs should provide the user with a new experience of instant-response, something that should be very appealing to all regular computer users.

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