i think you need both type cables:

- simple sata to sata cables to connect disks to motherboard ports

- SFF-8087 to SATA breakout cables(two for each SAS card) to connect disks to SAS controllers

 

Edit: More info here: http://lime-technology.com/forum/index.php?topic=20515.msg181975#msg181975

you will need Forward breakout cables, notice length also, 0.5m may be too short..

 

@uldise, looking at pics expansion boards I ordered, I see what you mean.  It's becoming less and less confusing.  Probably just jinxed myself.    Everything save for the cables will be here Wednesday or Thursday.  Thanks.

 

CW

 

... Since there are twenty connectors I am assuming, and I'm embarrassed to not know this, that each of these correspond to a drive bay so therefore I need 20 sata cables to go from each connector on the backplane to sata connectors on the mobo and expansion cards.

 

Yes, you need 20 SATA connections on THAT end ... but on the other end you need 4 mini-SAS connectors.    So you need 4 breakout cables for the 2 expansion cards (each of these has a mini-SAS connector on one end; 4 SATA connectors on the other) and 4 ordinary SATA cables to go from the motherboard ports to the remaining 4 connections.

 

This looks dangerous.  Here goes nothing...

 

CW

I'm surprised you went with the 4020.  It lists supporting SATA I and II drives for the drive cages.  I'm not sure if it matters.

Don't tell me I picked the wrong case 

Don't tell me I picked the wrong case 

you will be ok, SATA III is for SSD only now..

...  SATA III is for SSD only now..

 

NO !!  While it's true that only SSDs have sustained data rates above the SATA-II speeds, transfers to/from the drive's buffers will still occur at the maximum interface speed.

 

But that's moot anyway, as the bays in the 4020 support full 6GB SATA-III transfer speeds anyway (assuming, of course, that you're using SATA-III controllers).    Some sites mistakenly mention SATA-I/II in the description of the Norco 4020 (although they also mention 6GB transfers, which is, of course, SATA-III speed).  But the Norco site clearly shows that the case supports SATA-III for its drive bays:  http://www.norcotek.com/product/rpc-4220/

 

NO !!  While it's true that only SSDs have sustained data rates above the SATA-II speeds, transfers to/from the drive's buffers will still occur at the maximum interface speed.

Gary, can you explain this in more details?

when this buffers can help in everyday usage when you use spinners?

Every drive has a cache buffer that is used to help improve the effective performance of the drive.  For example, most 4TB drives have a 64MB cache.    Any reads/writes to this cache are transferred at the speed of the interface, since both the cache memory and the computer's memory are much faster than the drive interface.

 

Granted, this is a small % of the transfer activity for most use cases -- especially if you're simply streaming a video.    But in some cases it can be significant ... especially if your typical writes are small files that fit entirely within the cache.

 

Every drive has a cache buffer that is used to help improve the effective performance of the drive.  For example, most 4TB drives have a 64MB cache.    Any reads/writes to this cache are transferred at the speed of the interface, since both the cache memory and the computer's memory are much faster than the drive interface.

 

Granted, this is a small % of the transfer activity for most use cases -- especially if you're simply streaming a video.    But in some cases it can be significant ... especially if your typical writes are small files that fit entirely within the cache.

 

thanks for clarification..

this mean, you have a small benefit when you write a lot of small files that not exceeded 64MB in total in above 4TB drive example. when you write a lot of small files more than disk Cache then this will be slow anyway

 

original question was: "Don't tell me I picked the wrong case  ". and i say again, your case will work just fine

 

Famous last words but things are going together pretty effortlessly.  Waiting on 4x mini sas to 4 sata breakout cables.  My flash drive from LT shows it should be waiting on me when I get home.  Reading up now on preclearing drives for use in the server.  My wife is wondering why I'm building a server for our new house when the new house isn't going to start construction until next year but I told her it's all about priorities.

 

CW

But that's moot anyway, as the bays in the 4020 support full 6GB SATA-III transfer speeds anyway (assuming, of course, that you're using SATA-III controllers).    Some sites mistakenly mention SATA-I/II in the description of the Norco 4020 (although they also mention 6GB transfers, which is, of course, SATA-III speed).  But the Norco site clearly shows that the case supports SATA-III for its drive bays:  http://www.norcotek.com/product/rpc-4220/

 

I think some sites lists the old specs.  They released a newer version of this case.

The old version can be seen here.  http://www.xtremesystems.org/forums/showthread.php?202201-For-those-of-you-that-have-the-norco-RPC-4020-case-(WARNING-lots-of-images)

 

Well since you all were so EXTREMELY helpful in getting me pointed in the right direction I felt I at least owed you a progress report.  As so often happens life intervened with my plans to jump feet first and the parts sat on my dining room table for the last three weeks.  But, not just 10 minutes ago, I finished editing the bios and the server booted into unraid like a champ.  Now, shortsighted as I am, I have not Ethernet cable to connect the server to my network  but at least I know it won't explode when once I get it moved to the office and turn it back on.  I'm not naive enough to think its all downhill from here so I will inevitably chime back in here periodically to ask some questions (and by periodically I mean hourly  )  With 40tb, give or take, worth of data to transfer to the server drives I'm sure I will be at it for several days at the very least. But again, thank you sincerely to all who advised and corrected me on my hardware choices.  Have a great weekend!!

 

CW