mediamaestro

Need sata raid5 advice

Recommended Posts

I am having trouble locating the hardware I need, does anyone know if any sata raid controllers with a pci express x1 connector? I also need raid 5 support with online capacity expansion. I'm building a new system based on Asus P5AD2 motherboard, has support for raid 5 with software patch but its very buggy and no WHQL certification, and no online capacity expansion. Anybody set this up yet?

I really want to base my system off of this motherboard, at least 2 of my32bit pci slots will be used and I don't want to buy a 32bit pci raid controller becuase it would limit sata drives to 133Mbps instead of 150, is the speed difference noticeable? I plan on connecting (4) 250GB SATA HD's to this system. It would be really nice to utilze the x1 connection 500Mbps to prevent the bottleneck. The only pci express raid controller that I have seen uses a x4 connector.

The purpose of this PC will be a top of the line Windows Media Center 2005 PC, I am considering my storage needs 2yrs from now and possible upgrade scenarios (online storage expansion) I know I could use external drives to add on but I want my massive media collection 100% protected from a hard drive failure.

Any ideas will be greatly appreciated.

Share this post


Link to post
Share on other sites

I don't know of any PCI-e 1x but there're two that are available or will be out soon (though only for PCI-e 4x).

Areca ARC-1210/1220/1230/1260 (4/8/12/16-port)

Tekram SIR-1210 4-port or Tekram SIR-1220 8-port

And those won't be cheap ... I guess we'll have to wait a lil longer to see if some manufacturer decides to make a PCI-e 1x 4-port RAID-5 controller but I wouldn't bet on it.

Share this post


Link to post
Share on other sites

Thanks Doc, yeah I saw the card from areca, it is a little confusing, I think their pdf may be wrong, the website for this card says x4 and photo looks like a x4 connector.

I guess only time will tell, that price is a little steep, adaptec's 4port raid controller is only is only half that much model 2410sa, too bad I don't have a 66Mhz 64bit pci slot or their card would work for me, maybe I could still cram that card in the 32bit slot, I hear it would still work, although still limited by pci bus.

Share this post


Link to post
Share on other sites

There is no reason the PCI-e x4 (or x8 or whatever) cards can't be used in an x1 slot, and for most users that will be fine. Personally I would not buy a storage controller with a fan on it ... I wonder if the shipping cards will have fans or not.

Share this post


Link to post
Share on other sites

The connector for PCI-e 4x is bigger than for PCI-e 1x, it can be clearly seen in this picture of a mobo > http://www.xbitlabs.com/articles/editorial...-express_2.html .

And I doubt that the connectors on a PCI-e card can be keyed like the ones for PCI 64bit cards that also work in a PCI 32bit slot.

My conclusion is that a PCI-e 4x card would fit/work in the longer PCI-e 8x slot but not in the shorter PCI-e 1x.

mediamaestro

You have more options than that ultra-expensive Areca controller (which we don't know yet if it even fits into a PCI-e 1x).

The Adaptec 2410SA manual says "64-bit, 66-MHz PCI interface compatible with 32-bit/33-MHz PCI slots" so it would work in a regular PCI slot, same goes for the 3ware Escalade 8506-4LP.

There is a hexeditor hack to enable software RAID-5 in Windows 2000/XP Professional, this would be an option to go without a hardware RAID controller when you have enough SATA ports though it is somewhat slower than a hardware solution.

It is true, a PCI-e card has more bandwidth than a PCI one, 250MB/s dedicated bandwidth vs 133MB/s shared bandwidth (which is more like ~ 110MB/s in reality). This is an advantage when reading from a RAID-5 array since its read performance scales almost like a RAID-0.

The write performance on the other hand is much slower since the array has to calculate the XOR parity before writing to the HDDs and that makes writing much slower compared to reading. The performace for writing depends more on the controller than on the interface, at least for 4-port RAID-5 arrays.

Am I right when I think that the main purpose of your RAID-5 will be storage for media files? Or will you also do some video editing/encoding on that Media Center PC?

Even PCI RAID-5 controllers are fast enough for playing HDTV videos (which use up to 25 MBit/s) so it wouldn't really matter if it is PCI or PCI-e.

If you plan on doing some additional video editing/encoding than you might as well do that on a RAID-0 array and write it to the RAID-5 for storage after your work is done.

Share this post


Link to post
Share on other sites

PCI-E cards with fewer lanes may* be used in slots with more (the card negotiates the speed down to its speed), but cards with more lanes cannot be used in slots with fewer. They physcially won't fit. The PCI-E spec has one odd exception to this: PCI-E x8 cards are allowed in x4 slots if the slot is physically x8 but wired with x4 lanes (AFAIK this is just a wart to adress the expected number of lanes available in initial motherboard implementaions).

*Actually, the spec requires that x1 cards be usable in any slot regardless of lanes, but beyond that it's at the discretion of the implementer whether a card will be allowed to work in a slot with more lanes. They're only required to ensure that a card with the same number of lanes as the slot, and an x1 card, will work in that slot. We'll have to wait for implementations of slots and cards to see what the rule is in practice.

Share this post


Link to post
Share on other sites

I sent an email off to Areca to clarify the connector type, the pdf said x1/x8, I am guessing that it uses an x1 connector but if you put that card in an x8 slot it will utilize the increased bandwidth.

Its good to know that the adaptec 2410sa will work in a normal pci slot, my main reason for wanting a high end hardware controller is I want the OCE, online capacity expansion cabability. With that much data it will be nice to upgrade on the fly to larger drives down the road, yes the main use for the array will be media storage and playing content including HDTV, will use separate WD Raptor for video editing.

Also another main reason why I wanted to utilze the PCI express x1 connector for a RAID controller is that I only have 3pci slots which will be utilized by other devices. I wonder if an LGA775 board is worth all this trouble anyway, only features I see that would be nice are FireWire800, high def 8channel audio, DDR2. I'll let you know what areca says.

Share this post


Link to post
Share on other sites
I am guessing that it uses an x1 connector but if you put that card in an x8 slot it will utilize the increased bandwidth.

Nope, that doesn't work because all those single PCI-e datalines are running parallel into the PCI-e slot. If you plug a PCI-e 1x into a 8x it doesn't have the pins to connect to the other PCI-e datalines.

I wonder if an LGA775 board is worth all this trouble anyway, only features I see that would be nice are FireWire800, high def 8channel audio, DDR2.

DDR2 isn't worth the extra money right now, it isn't faster than comparable DDR memory (I think it's actually slightly slower due to higher latency).

A good Soundcard still beats any onboard sound, I'd say even that high def 8channel audio solution and you can always add a FireWire 800 card ... but you would need a board with 6 PCI slots , the three you already need plus RAID/soundcard/firewire ...

Dunno about the LGA775 board, I would prefer a AMD Athlon64 solution but that's my personal opinion ;)

wandergeist

You are correct, the BIOS has to support running a PCI-e card with less lanes in a bigger PCI-e slot. The german section of THW tested a videocard in a PCI-e 16x slot at 1x, (2x), 4x, 8x and 16x and they had to wait for a new BIOS from the mobo manufacturer (the german test can be found at http://www.de.tomshardware.com/graphic/20041105/index.html ). They taped the connectors so that the card used less of the PCI-e datalines for the slower speeds.

Share this post


Link to post
Share on other sites

Well Doc you have convinced me to forget about PCI express and to go with a socket 478 board with a bunch of 32bit pci slots. I will get the adaptec 2410sa and just live with the slight bottleneck, I probably will not notice the difference anyway. Also another factor I did not consider, audio quality, I will get better quality from SB Audigy 4pro board if I can find one versus the onboard sound.

Thank you all in helping me decide which route to go.

Share this post


Link to post
Share on other sites
There is a hexeditor hack to enable software RAID-5 in Windows 2000/XP Professional, this would be an option to go without a hardware RAID controller when you have enough SATA ports though it is somewhat slower than a hardware solution.

Snip

Can u tell me please where can I get infos about this hex Hack?

I'm disappointed about my 3Ware Raid card, and would like to give software RAID5 a try

Share this post


Link to post
Share on other sites

It seems that this article is only available on the german site of THG > http://www.de.tomshardware.com/storage/20041028/index.html (you can try http://babelfish.altavista.com/ for rough text translation)

But it probably won't be faster than your current hardware RAID, it was slower than 3Ware 9500S-12, Highpoint 1820A and Raidcore BC4852 with a 4x WD740 RAID-5 array on a new P4 system.

Beware: You can't transfer an existing RAID-5 array from hardware to software or the other way around.

I don't know if you already did this but you might want to try some different settings like WriteBack vs WriteThrough or adjust your stripesize (cluster size should be selected according to the stripesize). Those settings can make a difference when you look at the numbers here > http://www.xbitlabs.com/articles/storage/d...are-8506-8.html

Share this post


Link to post
Share on other sites

I finally got a response from Areca, they do make a RAID 5 controller with a PCI express x1 interface. ARC-1210 The card is a x1 card but will also use the bandwidth provided in an x8 slot. I am planning on getting this card for my internal RAID 5 solution.

Share this post


Link to post
Share on other sites
It seems that this article is only available on the german site of THG > http://www.de.tomshardware.com/storage/20041028/index.html (you can try http://babelfish.altavista.com/ for rough text translation)

But it probably won't be faster than your current hardware RAID, it was slower than 3Ware 9500S-12, Highpoint 1820A and Raidcore BC4852 with a 4x WD740 RAID-5 array on a new P4 system.

Beware: You can't transfer an existing RAID-5 array from hardware to software or the other way around.

I don't know if you already did this but you might want to try some different settings like WriteBack vs WriteThrough or adjust your stripesize (cluster size should be selected according to the stripesize). Those settings can make a difference when you look at the numbers here > http://www.xbitlabs.com/articles/storage/d...are-8506-8.html

Thanks very much!

I'll take a look!!

Share this post


Link to post
Share on other sites

If you purchase a Nvidia nForce 4 based Motherboard supported SLI (Asus, MSI and Gigabyte have all announced solutions) then you can run your video card in one slot (at PCI-e 8x) and a PCI-e 4x RAID controller in the 2nd PCI-e 16x slot (which should automatically cut back to PCI-e 4x to match the RAID controller.

That might be a good solution for you?

That's what I'm hoping to do when I finally purchase a new PC, which is currently looking like a January timeframe.

Regards,

Michael.

Share this post


Link to post
Share on other sites

Unfortunately I need two PCIe x16 slots to run multiple monitors....

As a sad geek I'm trying to get the following setup!!

PC using PCIe

IBM T221 DG5 Monitor running @ 3840x2400 (this requires dual DVI outputs from the card so that's a whole slot committed)

Also on the same machine I want to run 4 x Dell 2001FP monitors @ 1600x1200 each....so that requires one DVI output per monitor.

On top of this I want to run SATA Raid5 (minimum) for performance and integrity using at least 8 and preferably 16 disks (200GB each or perhaps 400GB if they come down enough in price).

The only way I can see to do it at the moment is......

Mobo with 2 x PCIe x16 using the slots to run a couple of Quadro FX (possibly the 3500's) and a QuadroFX 600 in a PCI slot....as well as using say the SATA RAID card in the PCI slot.

Now given the current development cycle I suspect I'm better off waiting till there are proper multiple PCIe x16 mobo's and Raid SATA(2) cards that will work off PCI x1 (although I suspect that SATA2 may saturate a PCIe x1 slot?).

I suspect in the short term I'll end up splitting the screen and RAID requirements over two machines....but that means another monitor required.

In summary I suppose my wishlist mobo would be.......

6 PCIe x8 slots (that would spread the bandwidth requirements the way I need them).

P

Share this post


Link to post
Share on other sites

If I were you, I would just use the 8 sata found on the Asus board. I dont think all that money you use to spend on the controller is worth it. You could just buy a few more drives and create a raid01 on the Asus board. Or do a raid 5 from windows. I dont think on a media box you will such a crazy array. You will most likely need to change everything in a few years, so the future upgrades shouldnt really matter. This is what I think.

Thanks

Share this post


Link to post
Share on other sites

On the issue of the Areca PCI express cards.....I have emailed areca.us and they cleared everything up for me. First of all the 4 port PCI express card is not released yet ARC-1210, could not get an estimate either. They do have the 8 port ARC-1220 out now, this does cost a pretty penny though, over $600, unsure of exact price. Also have not found a vendor in the U.S., I think they may sell it direct, www.areca.us

On the interface they said they are producing the card in 2 flavors, a pci-express x1 and x8, they did assure me it would work in a x1 slot, the ARC120-1x. I think I am going to just spend the cash and go with this card, it has all the features you could ever want, SATA II, RAID 6, online capacity expansion, and RAID level migration.

Share this post


Link to post
Share on other sites

I think I'll put my purchase of the 3Ware Escalade 9500S-4LP for my next system on hold for now until there're a few more facts out, especially the price for the PCI-e 1x 4-port card from Areca.

Thanks for sharing the info :)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now