Understanding Hrd drv controllers for unRAID (can i just use a JBOD controller?)

[gaikokujinkyofusho]

Hi I have been looking over the forum and trying to get up the speed on unRAID, its requirements, and hardware. One of the things i know least about is controllers. In the forum i see mentions of lots of nice controllers but they all seem to be RAID controllers. Would the RAID part of the controller be needed if one is using unraid? I had thought about (and i am trying to pinch every penny i can) finding a few 4 port, or more, JBOD controllers but it doesn't seem like most people are doing that. When i try to search for these kind of controllers i come up with brands like Addonics, StarTech, SYBA, Rosewill (http://bit.ly/MRzboU & http://bit.ly/Qe194S) which i am not wholly sure are great brands (that said i am just looking for good enough in terms of quality, in terms of speed i am willing to take a hit as i just need to be able to stream my bluray images to my htpc).

 

Is there a reason, other than performance, that many people seem to be opting for RAID controllers and is anyone familiar with the JBOD controller brands i mentioned before? Or are there any other suggestions for minimal/cost-effective controller options?

 

Any suggestions/comments would really be appreciated!

 

Cheers,

 

-Gaiko

[PeterB]

There are certainly people on here using Rocket 620/640 JBOD controllers.  Also, the likes of LSI do offer JBOD controllers, although I found that the RAID versions can be purchased cheaper than the JBOD versions.  Hence, many people buy a RAID controller then reflash it to JBOD mode.

[gaikokujinkyofusho]

Hi I have a few more questions. As i have been reading (head is spinning a bit) I see that some cards like the HighPoint RocketRAID 620 mentioned before support 10 drives via "port multiplier" but only have two physical ports, i feel foolish for asking but can one SATA cable have multiple plugs (ie support multiple drives) like the old IDE cables? Or more to the point, how does one connect 10 drives to a two port controller?

 

Sorry for such noob questions but this is turning out to be a steeper learning curve than i had originally expected (so your patience is really appreciated!!)

 

Cheers,

 

-Gaiko

[PeterB]

...how does one connect 10 drives to a two port controller?

 

You need an additional piece of hardware, called a 'port multiplier'.  Remember, though, that the base sata port is still limited to 1.5/3/6 Gb/s and the bandwidth of the host bus interface, which has to be divided among the connected devices.  With unRAID, this restriction will be most obvious during parity checking/building.

[gaikokujinkyofusho]

A port multiplier *and* hard drive controller? I am confused. I just need a way to plug in a bunch (at least of drives into my computer so unRAID can do its thing. When i look online it seems like most cards that are for hard drives have #1 RAID #2 port multipliers built in #3 2-3 physical sata ports that a single drive can be plugged into. So to be able to plug in 8 drives I would need, for example two Syba SIL3124 PCI (http://bit.ly/QvvZF5) cards that have 4 physical SATA ports each? and that is it (bandwidth of the host interface issues aside, point taken though).

 

Thanks!

[BobPhoenix]

If you insist on PCI you can get a SuperMicro AOC-SAT2-MV8 and use it in a PCI slot.  It is a PCI-x card (slots for old server boards) but will work in a normal PCI slot.  This will give you 8 ports on one card.  It will be slow but it shouldn't be any slower than 2 SIL3124 cards in multiple PCI slots since it is the bus that would be slowing you down not the card.

[opentoe]

If you insist on PCI you can get a SuperMicro AOC-SAT2-MV8 and use it in a PCI slot.  It is a PCI-x card (slots for old server boards) but will work in a normal PCI slot.  This will give you 8 ports on one card.  It will be slow but it shouldn't be any slower than 2 SIL3124 cards in multiple PCI slots since it is the bus that would be slowing you down not the card.

 

What do you mean it will be slow?

[BobPhoenix]

If you insist on PCI you can get a SuperMicro AOC-SAT2-MV8 and use it in a PCI slot.  It is a PCI-x card (slots for old server boards) but will work in a normal PCI slot.  This will give you 8 ports on one card.  It will be slow but it shouldn't be any slower than 2 SIL3124 cards in multiple PCI slots since it is the bus that would be slowing you down not the card.

 

What do you mean it will be slow?

If you get a parity check speed of 60-80MBs with PCI-e you could expect 10-30MBs possibly less with this in a PCI slot and 8 drives.  If you have a PCI-x slot then you would be able to increase that back close to the same 60-80MBs speed.  On my X7SBE with 22 drives, 2 AOC-SAT2-MV8s plugged into the 2 separate PCI-x channels I got between 60-80MBs on parity checks.