Four X25-E Extreme SSDs Combined In Hardware RAID

theraindog writes "Intel's X25-E Extreme SSD is easily the fastest flash drive on the market, and contrary to what one might expect, it actually delivers compelling value if you're looking at performance per dollar rather than gigabytes. That, combined with a rackmount-friendly 2.5" form factor and low power consumption make the drive particularly appealing for enterprise RAID. So just how fast are four of them in a striped array hanging off a hardware RAID controller? The Tech Report finds out, with mixed but at times staggeringly impressive results."

Comments

Solid State Slashdot Drive.

[Ostracus]

"So just how fast are four of them in a striped array hanging off a hardware RAID controller? The Tech Report finds out, with mixed but at times staggeringly impressive results.""

So in other words I'll get First Post much faster since slashdot switched over.

Re:Oh good

[spazdor]

'cause regular hard drives usually survive 5 years in an enterprise environment, yep yep.

Actually, that RAID card seems more interesting

[the_humeister]

A 1.2 GHz processor with 256 DDR2 memory? Holy crap! That's faster than my new Celeron 220! And the perennial quesion: can this thing run Linux?

Re:Actually, that RAID card seems more interesting

[Wonko the Sane]

That RAID card was the bottleneck. It can't support 4x the raw transfer rate of a single drive.

Re:Actually, that RAID card seems more interesting

[default luser]

Actually, I felt that the limiting factor was probably the craptastic single-core Pentium 4 EE they used to run all these benchmarks.

What, you shove thousands of dollars worth of I/O into a system, and run it through the paces with a CPU that sucked in 2005? I'm not surprised at all that most tests showed very little improvement with the RAID.

What I want to see

[XanC]

Is 4 of these in a RAID-1, running a seek-heavy database. Nobody does this benchmark, unfortunately.

Re:What I want to see

[Aqualung812]

Why not run RAID-5 (or 50 or 15) if it is seek-heavy? I thought RAID-1 was only used if you had to deal with a lot of writes. Those are slower on 5 than 1, but 5 is much faster for reads.

Re:What I want to see

[afidel]

Good controllers do read interleaving where every other batch of reads is dispatched to a separate drive.

Re:What I want to see

[Anonymous Coward]

RAID5 has terrible random write performance, because every write causes a write to every disk in the array. it's VERY easy to saturate traditional disks random write capabilities with raid5/6. So, it's rightly avoided like the plague for heavily hit databases.

I'm not certain how much of the performance hit is due to latencies of disks. So i feel it would be an interesting test to also see raid5 database performance.

Also, Raid1 (or 10 to be more fair when comparing with RAID5) in a highly saturated environment. reading data should do marginally better than Raid5 since you don't lose a disk to parity--and any raid controller worth it's salt will send independent reads or round robin your read's to both disks).

Then, there is also that whole disk failure thing. It's a huge performance hit to lose a disk in RAID5. For that reason alone in a heavily hit environment it would probably be best to avoid it.

Disk failure is not an IF, but a WHEN. i Dont care what manufacturers say about MTBF's.

Re:What I want to see

[XanC]

RAID5's write performance is so awful because it requires so much reading to do a write.

I have to read from _every drive in the array_ in order to do a write, because the parity has to be calculated. Note that it's not the calculation that's slow, it's getting the data for it. So that's multiple operations to do a simple write.

A write on RAID1 requires writing to all the drives, but only writing. It's a single operation.

RAID1 is definitely faster (or as fast) for seek-heavy, high-concurrency loads, because each drive can be pulling up a different piece of data simultaneously.

Re:Oh good

[LordKaT]

'cause SSD's don't cost $300-$500 more than their spindle counterparts, yep yep.

Re:Oh good

[poot_rootbeer]

I'll be sure to do that, and replace them every 5 years when they run out of write operations.

Winchester drives, on the other hand, use a time-honored complex system of delicate moving parts, and last virtually forever. They certainly do not start experiencing sudden failures if kept in continuous service for more than 5 years.

Re:Oh good

[ChienAndalu]

Make that 228 years.

Life expectancy 2 Million Hours Mean Time Before Failure (MTBF)

Hint: learn about "wear leveling"

If I keep my current 15K drives that long

[Shivetya]

I will be surprised.

See, in the enterprise environment that I work in the majority of our big hardware is leased. I am quite willing to use what I can to maintain performance and reliability. That being said my system is built entirely on 15K drives of various sizes. I am not worried about five years or so of read/write that SSD drives have, all I want to see is a track record. I expect to replace most of the drives I have now within five years so this "five year limit" many like to toss out is immaterial to me. Reliability over that lifetime is of more importance.

Besides, the nice benefit of SSD drives is I don't need special enclosures (read: ones that can handle the torque these puppies can put out)

Re:paging benefits?

[tom17]

I really don't get this obsession with page files these days. Say you have 4GB ram and an 4GB page file. Memory is cheap these days, so rather than using 4GB of (relatively slow) SSD, why not just get another 4GB ram?

Redundant Array of what?

[telchine]

This is a very expensive solution. What part of Redundant Array of Inexpensive Disks don't they understand?

Re:Redundant Array of what?

[grub]

Independent disks. And remember that some high end SCSI or Fiberchannel RAIDs have never fit the antiquated "Inexpensive" bit.

Re:Redundant Array of what?

[Ioldanach]

That's right. Marketing switched "Inexpensive" for "Independent" years after the term was coined, because they couldn't convince people to buy their non-Inexpensive disks for RAID use as easily under the old meaning.

Re:Redundant Array of what?

[afidel]

Dude, 4 of these drives can keep up with my 110 spindle FC SAN segment for IOPS. Here's a hint, 110 drives plus SAN controllers is about two orders of magnitude more expensive than 4 SSD's and a RAID card. If you need IOPS (say for the log directory on a DB server) these drives are hard to beat. The applications may be niche, but they certainly DO exist.

Re:Oh good

[spazdor]

Your enterprise environment must not be hitting its drives very hard.

Where SSDs is in disk operations that are usually lagged out by seek times; a big unwieldy database that gets a lot of writes and no downtime, for instance, is happiest when it lives on a striped SSD array.

Coincidentally, this is exactly the type of workload which is most likely to shorten a magnetic drive's life.

Re:Oh good

[FauxPasIII]

> 'cause SSD's don't cost $300-$500 more than their spindle counterparts, yep yep.

Hint: Enterprise storage purchasing often looks at dollars/IOPS rather than dollars/GB.

Comparisons a little unfair in places

[heffrey]

It seemed a little unfair that they only used the nice hardware RAID controller with the Intel SSDs. I would have liked to see them use it with all the other disks to get a more level playing field.

Re:paging benefits?

[Vectronic]

I'm no expert, but wouldn't that be a redundant statistic? if it handles normal read/writes faster than a disk drive, then could you presume paging would be faster as well?

Although it would be interesting to see a RAM-less PC try and run on SSD's only... somehow using normal data read/write, and memory read/write on the same SSD (if thats possible). Guess that's what we'll end up with eventually anyways, where your amount of MEM is the amount of free-space you have on your SSD, no longer seperated components.

Re:Oh good

[Anonymous Coward]

"Enterprise storage purchasing often looks at dollars/IOPS rather than dollars/GB."

Which is good news, as this Intel Slashdot advert says its "compelling value if you're looking at performance per dollar rather than gigabytes.".

Re:paging benefits?

[guruevi]

SSD shouldn't be for paging. That would become very expensive (even with wear leveling) if you have a minimal amount of RAM (say 256M) to run large (say 16G) operations. It would also be slow since you have the overhead of whatever bus system your hard drive/ssd is connected to.

Technically hard drives aren't supposed to be paging either, it's just a cheap and simple trick to avoid having people pay a lot for (expensive) RAM or have their programs crash when occasionally they run out of RAM. However if your system is paging heavily it's better and faster with more RAM.

Anecdote: I worked at a place once where cheap ($500) hardware was sold as dedicated SQL/IIS servers (you could fit 10 of them in 5U) and a lot of customers thought they could run whatever they wanted (Microsoft ran MSN for a whole country of one for a while) in them but they only supported a maximum of 2G RAM (4G according to BIOS but the modules back then were too expensive). Of course PHB just said: let them swap and besides the heavy slow downs they ran fairly fine. Well, those heavy users all crashed their software-RAID's in less than a year (the heavy load made Windows get the RAID system out of sync and then you had the first hard drive fail). The temperature was fine but simply swapping out was too much for the cheap hard drives (Maxtor and Seagate) and they all failed.

Re:Oh good

[neoform]

I must be doing something wrong then. Should I put my computer in the freezer when I'm not using it or something, like, to keep it fresh longer?

Re:Oh good

[bluefoxlucid]

All modern hard drives are Winchester drives; Winchester drives are just the first iteration, made by IBM, who figured they'd ship two 30MB platters and name the hard drive after the Winchester 30-30 rifle. Who the hell modded you insightful, especially for claiming a system of delicate moving parts lasts virtually forever...

Re:paging benefits?

[Wonko the Sane]

* AMD opteron boards can use ordinary DDR2 but the CPU performance sucks compared to the aforementioned xeons.

If you go multiprocessor (not multicore) then you get much higher memory bandwidth (NUMA). Sometimes that matters more than CPU power.

Re:Oh good

[CMonk]

I think you're comparing against SATA drives. People that worry about IOPS are normally using FC drives which are much more closely aligned in price with SSDs. (btw, been a while since I was in the market for FC drives)

Re:New acronym: RAVED?

[CompMD]

No, its got a cooler acronym, RAVEN: Redundant Array of Very Expensive Not-disks-but-some-silly-stack-of-flash-memory-chips.

Re:Oh good

[DMalic]

It's obvious sarcasm.

Re:paging benefits?

[Cthefuture]

I don't think anyone should be using a page file at all if you have 4 GB or more of RAM. Maybe even 2 GB. It just doesn't make sense. With that much memory what good is a 512 MB page file going to do really? And if you're swapping more than 512 MB of RAM to disk your machine is going to be thrashing like mad and unusable anyway.

It's stupid that many OS's allocate 2 times your RAM as a page file. Are you really going to swap 8 GB of RAM to disk? I mean seriously, that would be unusable.

Even when I had 2 GB of RAM I never used a swap file and now with low-end machines running 8+ GB (only about $100 of RAM), page files just don't make sense any more.

Fantastic Slashvertising

[damn_registrars]

Intel's X25-E Extreme SSD is easily the fastest flash drive on the market, and contrary to what one might expect, it actually delivers compelling value if you're looking at performance per dollar rather than gigabytes

I hope someone got a healthy commission from Intel for writing that...

Re:Oh good

[horza]

MTBF is a highly inaccurate way to show how long you should expect a drive to live. The whole Seagate Fiasco is a prime example of why NOT to believe them.

Misuse of a statistical figure is a problem with those misinterpreting it. Obviously things have changed since schools taught the difference between the mean, the mode, the median, and the minimum. If I run an ISP then MTBF is useful for me to calculate costs, both in replacements and labour costs. It's not supposed to be a measurement for consumers though that will be buying single unit quantities.

Buying a hard drive is like buying a washing machine. If I'm lucky it will go on practically for ever. On the other hand if I'm unlucky it could die tomorrow. As Piranhaa says, there are too many variables. All I can go on is that if it comes with a garauntee of 3 years then I assume the manufacturers have designed it to mostly exceed that figure otherwise they would end up losing money on the product. I still have to ensure I have a contingency plan in case it breaks down.

Phillip.

Re:paging benefits?

[ErikZ]

I'm Betaing Windows 7. Before going to bed I set up a swap partition for it. After getting up the next morning and checking, it was full.

I have *no idea* what W7 put in there while I was sleeping.

USB flash drive RAID?

[hack slash]

When will someone come up with a hardware or software RAID solution to enable several USB flash drives to appear as a single drive on Windows? with relatively reliable & fast (12MB/s write, 30MB/s read) 16GB flash drives as cheap as £16 each I'd love to cram as many as I could inside my Eee and have them appear as a single drive instead of many individual drives.

I hate to ask but...

[Douglas Goodall]

As SSD drives come into the market used, how will people know how close these drives are to "used up". That is to say, we will have to worry that these cheap drives on ebay will have lots of "bad" spots that can no longer be written. We are going to be needing a program or device of some kind that can certify the state of a drive so as to set a fair value on it. I expect a lot of unhappy people when used drives get installed and start failing soon after. There will have to be some pretty sleazy warrantees to cover used SSDs.

Agreed

[LostMyBeaver]

My wife who loves me very much bought me the 28 port 512mb version of this hard drive controller for Christmas and I have loved it, but I feel like I'm wasting it by running it in a shitty Core 2 Quad motherboard instead of a Xeon motherboard.

I have actually run this exact controller in a Pentium M motherboard during my 3ware to Adaptec transition phase, and the results are entirely different. Especially since the Adaptec drivers are poorly suited for single core systems. After all, you just don't add a $300-$1700 controller to a computer that costs more to ship than to buy on eBay.

So far as I'm concerned, the test is entirely unrealistic and invalid. It's time these guys "rebooted" and got at least a quad core PC, at least using the x58 chipset, bus performance is less of an issue and peripherals should perform at their full potential.

Re:paging benefits?

[illumin8]

I'm Betaing Windows 7. Before going to bed I set up a swap partition for it. After getting up the next morning and checking, it was full.

I have *no idea* what W7 put in there while I was sleeping.

In any modern operating system, including Windows , swap isn't just used for out of physical memory conditions. It's also used to "page out" portions of the operating system and libraries, shared objects, dlls, etc., that aren't being used at the moment. This actually speeds your system up by allowing more memory to be used as disk read/write cache.

I've looked at Linux boxes with 64GB of memory in them and only using 25% of that. I usually get asked by someone, "wasn't 64GB enough? Why is there some usage in swap right now?" It's normal, I explain. The kernel just pages out sections of Linux that aren't needed, to free up more RAM for filesystem caching.

I think perhaps Windows 7 just has a more aggressive way of doing this, probably because if you need to use some obscure Windows Directmedia SuperDRM doubleplusgood Plugin X, it's just as fast to reload it out of swap into memory as it is to load the binary from disk. But 99% of home users will never load that plugin so it can stay safely swapped out, giving you more precious memory for applications and disk cache.