FS: Supermicro BPN-SAS2-846EL1 Backplane with SAS Expander

Zarathustra[H]

Zarathustra[H]

Extremely [H]
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For sale is a Backplane (with metal bracket) I removed from my Supermicro SC846 chassis.

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The Backplane has an internal SAS expander and is designed to be connected to your SAS Raid Card (or HBA) with a single 4x SFF-8087 cable. (Can accept adapter cables for SFF-8643 controllers) It is SAS2 (6GB/s) which allows up to 24 SAS or SATA hard drives to share 6x4 or 24Gbit/s of bandwidth.

If you look closely it has three SAS connectors. One is the primary input from your SAS controller. One is for cascading with another Backplane. It is unclear to me what the third one is for, but it does not support dual SAS configurations for more than 24Gbit/s bandwidth.

The Backplane works perfectly. I'm only selling it because I wanted to switch to a direct attach version without an expander. (This is not for everyone as it will require SAS controllers with 6 connectors, 24 lanes)

$175 or best offer.

Here is my heat, if anyone still uses that!
 
This is crazy to me haha. I thought that for every 4 drives there was 1 sas connector.
 
EnzoFX said:
This is crazy to me haha. I thought that for every 4 drives there was 1 sas connector.
Click to expand...

Thats' what SAS expanders do! They can either be separate boards that just take one x4 cable in, and offer several out, like the HP ones that used to be very popular, and had a thread dedicated to them here, or they can be built in to something else, in this case the backplane of the server, which is a very common design on rackmount servers.

It helps with both cost saving and convenience. Since many of these backplanes are used for large storage volumes using predominantly hard drives, you arent going to benefit much by running independent direct connected lines to each drive, as they will never use all of that bandwidth. As an example, the backplane being sold uses a single 4*6Gbps cable for 24GBps, which is 3GB/s. There aren't too many storage pools with hard drives that will saturate that, and even if you had one, now if you need to get that dat aoff the server, you are going to be bandwidth limited unless you go to 40Gbit or the new 25gbit network standards.

The cost savings you get in exchange is that you can run a cheap little RAID card instead of one with many ports, which tends to get quite pricy, and in most cases doesn't offer much if any benefit.
 
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