VelociRaptors In RAID 5, A Case Study In Speed

The Data Center, HotHardware's new community for IT professionals, is sponsored by Dell's Future of Storage. This article is part of our ongoing series of topics and discussions related to IT, Enterprise Storage and related storage technologies.

If you were the type to think of 2.5" drive technology only in terms of notebook products, then recently, Western Digital probably helped expand your horizons a bit.  With the release of their VelociRaptor 300GB SATA hard drive, mainstream users were exposed to the advantages of the high transfer rates associated with 2.5" platters rotating at 10K RPM, with four access heads pulling data.  Though packed in a 3.5" form-factor for desktop system compatibility, the 2.5", dual 150GB platter platform that the VelociRaptor was built on allows it to outperform virtually all standard 3.5" SATA drives on the market today, even WD's 10K RPM Raptor WD1500 series. 

However, the VelociRaptor is definitely targeted to the performance enthusiast, with a price tag currently at $1/GB (MSRP $299).  Regardless, when you consider the upside potential performance gains and the fact that a hard drive is easily the slowest component and limiting factor in many areas of overall system responsiveness, it's obvious this new Raptor will do well from a retail perspective.  But what about the Data Center?  Actually, when you consider the average 146GB 10K RPM SAS drive retails for about the same price as the new VelociRaptor but with half the capacity, just maybe a few folks in IT will poke their heads up out of their cubicles long enough to give the VelociRaptor a look as well.  Of course, that all depends on the usage model, as clearly there are other advantages to SAS in terms of error reporting and recovery, but if the metrics are all about reliable, cost-efficient performance, there may be a solid case for the VelociRaptor in that storage server as well.

It was with a few of these questions in mind that we decided to RAID up not two but three WD VelociRaptor drives in a RAID 5 configuration with an Areca PCIe X8 hardware RAID card, to see what the numbers looked like.  This is only a quick-take on read performance but it certainly gives you a sense of scale and what these drives are capable of in the right environment.

WD VelociRaptor 300GB X 3 - RAID5 Areca PCIe Hardware SATA RAID
Windows Vista SP1 - NTFS

WD VelociRaptor 300GB X 3 - RAID5 Areca PCIe Hardware SATA RAID
Windows Vista SP1 - NTFS

A quick gander at the graph above shows relatively linear performance across the entire 600GB volume with some small vallies along the way.  The burst speed recorded was robust 598MB/sec which is about on par with what we've seen from WD's Raptor WD1500 line in this configuration.  However, average read performance is through the roof, with a 209.4MB/sec land speed record set for what we've seen in our labs and about a 33% performance gain over what we've seen with Raptor WD1500 drives in RAID 5 on the Areca controller.  Finally, random access clocks in at a snappy 7.2ms. 

So in short, whether you an end user with just a need for speed, or an enterprise user looking for mission critical performance, the VelociRaptor definitely has strong merits.  Straddling the cost line between standard, bulk SATA drives and high-end 10K RPM SAS, WD's new beast offers an interesting and compelling paradigm.

Rendus:

So... Where's the article? I see a decent teaser for something, but... Other than two artificial benchmarks...

Oh. Wait. That's it? Wow. "Fast hard drives are even faster in artificial benchmarks when RAIDed together. News at 11."

Legitimate question, Rendus!  This article is actually a follow-up.  The original launch article is here:
http://www.hothardware.com/Articles/Western_Digital_Velociraptor_300GB/

dizowned:

rapid,
what you've described is about as good as your going to get for typical home use. I wouldn't say that you need a standalone raid controller as that they can be expensive. Using a decent mainboard with onboard raid should be fine, and a raid 5 with nice reliable drives will also be fine. If you want speed I'd honestly have to recommend the Raptor series - although I'm biased as that I've been running a 4 drive Raptor setup for the last 3 years and these puppies are still putting out some nice numbers.

Hey Guys, Unfortunately I would not recommend RAID 5 with an onboard integrated RAID controller.  You're speaking of the RAID capabilities of the average Southbridge, right?  In that case you're looking at "software RAID", which for RAID 0 or RAID 1 is just fine beause it as relatively low CPU overhead.  However, for RAID 5, the CPU will be doing all the parity calculations and in a RAID 5 set, with three or four drives, that's going to eat up any performance gain you'll realize from a RAID 5 config.  RAID 5 on any Southrbridge (Intel's ICHR or NVIDIA's MCP ) that we've seen is actually slower by a lot. 

For RAID 5 you really need a hardware based RAID controller, and preferably in a PCIe slot, for best performance.  This is what we use:  http://hothardware.pricegrabber.com/search_getprod.php/masterid=16593069

It has a little Intel IOPs CPU on it and really works great.  We've even had a drive go bad in the array at one time.  Just popped another identical drive in, created a hot spare in the RAID BIOS and the card automatically rebuilt the array back to normal (which is the way RAID 5 is supposed to work).  Pretty sweet but yes, one of these cards will run you around $300ish so it isn't cheap. 

Davo:

Hey Guys, Unfortunately I would not recommend RAID 5 with an onboard integrated RAID controller.  You're speaking of the RAID capabilities of the average Southbridge, right?  In that case you're looking at "software RAID", which for RAID 0 or RAID 1 is just fine beause it as relatively low CPU overhead.  However, for RAID 5, the CPU will be doing all the parity calculations and in a RAID 5 set, with three or four drives, that's going to eat up any performance gain you'll realize from a RAID 5 config.  RAID 5 on any Southrbridge (Intel's ICHR or NVIDIA's MCP ) that we've seen is actually slower by a lot. 

For RAID 5 you really need a hardware based RAID controller, and preferably in a PCIe slot, for best performance.  This is what we use:  http://hothardware.pricegrabber.com/search_getprod.php/masterid=16593069

It has a little Intel IOPs CPU on it and really works great.  We've even had a drive go bad in the array at one time.  Just popped another identical drive in, created a hot spare in the RAID BIOS and the card automatically rebuilt the array back to normal (which is the way RAID 5 is supposed to work).  Pretty sweet but yes, one of these cards will run you around $300ish so it isn't cheap.

Ackkk... I edited the typos out of that one but the system doesn't catches it in the email notifications so make sure you go to this thread to read it again.  Didn't mean to say "memory controller". 

Sorry to post semi-off topic here.....but Davo, you should write up an article just discussing RAID in general around your labs...hardware you use, configurations you set. I would be very interested to see how engineering buffs like you and Marco throw storage together (whether it be in the form of servers or on singular rigs).

What do you think buddy?

My comment is deffinately off topic, but relevant I feel. i just noticed that techspot put together a 08' builders guide... I'd love to see Hot Hardware do 1 as well!

Check it out HERE

Davo:

Heya Ice, not off topic at all. No worries... RAID is always an interesting dicussion point for sure. We'll be revisiting that I think in the near future. We have lots of ideas actually. I personally use RAID 5 in my rig. It offers nearly the speed of RAID 0 with the parity checking and resilancy of RAID 1. For end users, if you have the budget, it's worth it. If a drive fails you just replace it and rebuild, no data loss. However, you definitely need a hardware RAID card for it, in my opinion, because of the overhead. That's where the cost comes in.

Regardless, more to come in this space, I assure you.

Thanks!

OK that I too would like to see, hopefully including ideas one some of the better raid controllers (perhaps with a cost to performance ratio).  I wanna get started with this sort of stuff, but alas there are things even I don't know completely.

Yes, this is something we've done before too with our Holiday Shopping guide but would like to have as a regular occuring segment. http://www.hothardware.com/Articles/Holiday_Gift_Guide_Extravaganza/

Rendus:

So, where's this article's follow-up? The one where real-world testing is done? Where it's compared to a RAID-5 of other drives?

This 'article' had all the quality of a HardOCP forum post wherein someone states 'lol raptors r fast in raid am i rite? lol'

Rendus, again, this was more of a fun experiment than anything else.  We did full VR testing in the original piece that I linked above.  We may come back and look at various RAID setups with the VRs but in time.  This wasn't meant to say anything is better than anything else, just that here's a taste of what things look like.  Obviously it created a bit of buzz so we'll likely come back with more.  Be patient though! 

Davo:

Yes, this is something we've done before too with our Holiday Shopping guide but would like to have as a regular occuring segment. http://www.hothardware.com/Articles/Holiday_Gift_Guide_Extravaganza/

This also we be fun to see from you guys every 6 months or so......*thinks quickly, gets a abicus and slides beads for 27 minutes* ... Davo are you aware its been about 6 months since you have done this article? That means that you guys should do a "gift guide" for us again!

As far as RAID is concerned as I said before I would like to know just how you have storage set up around you lab and servers.....as specific as you wanted to get...I get enough "what RAID is" from reading but I guess I want it straight from the horse's mouth as to how real-life billionaire businesses (such as HH ) and everyday consumers take adavantage of it

I recently built a workstation with storage speed in mind and opted not to go with the onboard Intel Matrix raid but rather use an Adaptec 5405 SAS Raid controller and 4 VelociRaptor drives in Raid 5. I chose the Adaptec card because of my past experiences with them and the ultrafast 1.2GB/s bandwidth available as 4 x 300MB/s channels. Needless to say, shelling out $1560 (wholesale) for a storage array on a personal computer is a little excessive to say the least but all said i am extremely happy with the results.

As you can see in the pictures below the benchmarks proved that this combination is lethal (In a good way).

In Summary:

279 MB/s Average read with 440.5 MB/s burst on HD Tune 2.55

302 MB/s Average read with 838 MB/s Burst Speed on HD Tach 3.0.4.0

i think i just drooled on my keyboard

warlord:

i think i just drooled on my keyboard

This system may be sold to make way for an 8 drive system with an adaptec 5805 and the new backplane compliant VelociRaptors. Hot swap bays with lights flashing are teh kewlness.

warlord:

i think i just drooled on my keyboard

 Dang I just peeed on myself but it all about the money right now. Lol[:'(]