Cheap RAID card any good? 1

[Nelviticus]

I want to set up my system with RAID 1 but my stupid motherboard (an Asus P5B) only has one RAID-capable internal SATA port - to do RAID your second drive needs to use the external SATA port.

So I've been looking around for a PCI-express SATA RAID card and I saw this one for under 15UKP (manufacturer's page here). It seems almost too good to be true and I can't find any reviews for it, although Scan are a highly-regarded retailer so I don't think they'd sell rubbish.

Does anyone know whether it is likely to be any use? All the other PCIe SATA RAID cards I've seen start at four times this price but I don't know enough about them to figure out what one card could do that another couldn't.

It is only 1x PCIe but I have read reviews of other 1x cards (like this one) which give good results, so I assume that's not a significantly limiting factor.

I know for that price I could just 'suck it and see' but I'd also have to buy the drives and spend the time setting things up.

Any advice gratefully recieved!

Nelviticus

 

[wahnula]

Two SATA ports??? How can it run RAID 5 or 1+0 like the specs say? A time to worry. I would spend a bit more and get a card with a known good controller, like 3Ware, Adaptec, Promise, Sil, or JMIcron.

Tony

Users helping Users...

 

[Johnthephoneguy]

My P5B has no problems with raid, are you sure you have that model or are looking at the right place? I have 4 SATA connected right now.

JohnThePhoneGuy

"If I can't fix it, it's not broke!

 

[BadBigBen]

rule of thumb:

If it sounds too good to be true, then usually it probably is...

meaning, there is a reason why they are cheap, and that usually incorporates cheap/old SATA controller chips... they are fine for adding SATA ports to PC's and will give you simple RAID, but usually are not robust enough for prolonged work...

at work, we use two different types of SATA controllers, the first is an 'el cheapo' two port, similar to the one above, and we do not RAID them at all, they get used to supply SATA capability to older hardware... the second is a 3ware (4 to 12 ports) cards, now these babies will support all the RAID that you will ever need and are robust, downside on these is the price (EUR 259,00 for the 4 port version)...

@Johnthephoneguy - the p5b mainboard behaves like Nelveticus described, the JMicron JMB363 chip is responsible for the RAID on that mainboard, you may have the Deluxe version where the RAID functionality is controlled by a different chip (Intel Matrix)...




Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[Nelviticus]

If you look at the manufacturer's page it does say that it can only do RAID 5 or 1+0 with a port multiplier. But I'm only interested in RAID 1 so a two-port card is fine for me.

I believe that the Deluxe version of the P5B uses the Intel ICH8R southbridge, which supports RAID, but I just have the vanilla P5B which uses the ICH8 (non-R). The mobo has an extra JMicron controller for RAID and IDE. I double-checked the manual and the Asus forum last night - for RAID on the vanilla P5B, you definitely have to use the internal JMicron port and the eSATA port.

Nelviticus

 

[Nelviticus]

Ah, looks like you replied while I was typing Ben.

So what do the 'el cheapo' cards lack? Are you saying they're more likely to fail, or that it will be slower than a single drive, or that the CPU load for RAID will be a lot higher than a more expensive card?

I'm just wondering whether the extra expense would be worth it - I don't mind not having ultimate performance but I don't want to end up wishing I'd stuck to a single drive!

Nelviticus

 

[BadBigBen]

Firmware/driver based RAID ("fake RAID")

Operating system-based RAID cannot easily be used to protect the boot process and is generally impractical on desktop version of Windows (as described above). Hardware RAID controllers are expensive. To fill this gap cheap "RAID controllers" were introduced that do not contain a RAID controller chip, but simply a standard disk controller chip with special firmware and drivers. During early stage bootup the RAID is implemented by the firmware; when a protected-mode operating system such as a modern version of GNU/Linux or Microsoft Windows is loaded the drivers take over.

These controllers are described by their manufacturers as RAID controllers, and it is rarely made clear to purchasers that the burden of RAID processing is borne by the host computer's central processing unit, not the RAID controller itself, thus introducing the afore-mentioned CPU overhead. Before their introduction, a "RAID controller" implied that the controller did the processing, and the new type has become known in technically knowledgeable circles as "fake RAID" even though the RAID itself is implemented correctly.

Source: Wikipedia

If you are going to use it for a home environment, then it would be alright to go ahead and use it, since you are aware of the performance that a RAID 1 setup will have, lower throughput (write speed is reduced due to the mirroring) and capacity will be set to the smallest drive you are using...

suggest that you get yourself a second card as a backup (or at a later time), in case the first fails, so that you can get at the data...

in a work environment, where stability is the key, I would never use that card or another 'el cheapo' (we use SIL 3512 (SATA I) from a no-name manufacturer)...


Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[Nelviticus]

Aha, I had read that article before but thought it only applied to the controllers on cheap motherboards. It sounds like the card I linked to will be no better or worse than most motherboard-based RAID then, in which case I might go for one.

It's annoying - I already have an XFX Revo 64, which is a proper hardware RAID controller, so the PC sees the array as a single IDE drive and Windows doesn't need any extra drivers installed. That was even cheaper - 10UKP in one of Scan's "today only" offers - but it's PCI, not PCIe, so if I added a second one they would share the same bus and speeds would be terrible. One card saturates the PCI bus as it is. It proves that full hardware RAID doesn't have to be expensive, but unfortunately they don't do a PCIe version

Ideally I want to have my data and applications on the existing RAID array and my system on another. At the moment it's all on the same one which slows things down, as the page file is on the same 'drive' as all the data. Not terrible, but I know I'd get a performance boost from having OS and data on separate arrays.

Thanks for your input.

Nelviticus

 

[kmcferrin]

I wouldn't worry too much about the performance hit of the software/firmware based RAID as long as you're doing simple mirroring, or even plain striping. The big performance hit comes from parity calculations used in RAID5 and other parity-based RAID levels.

________________________________________
CompTIA A+, Network+, Server+, Security+
MCSE:Security 2003
MCITP:Enterprise Administrator

 

[BadBigBen]

Nelveticus,

you are always welcome, and as kmcferrin mentions it should not matter too much, except on a RAID 5 setup...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[jurgen36]

Have a look on E-bay. I bought a 4 channel Sata raid card for less then 20 Euros. Can handle raid 0,1,2,5 and 10. Work very well indeed it is also bootable. Fitts into any free PCI slot.


Jurgen