BYO SAS Expander Deal: Intel RES2SV240 SAS 2 Expander

Recently forum members have found an excellent deal on the Intel RES2SV240 SAS expander. You can find the forum thread here started by Atomicslave. For those not familiar with the RES2SV240 it is a 24-port LSI/ Avago-based SAS expander. The card is neiter RAID controller nor SAS HBA. Instead, the SAS expander works in conjunction with a SAS HBA or RAID controller to add connectivity for more devices. Most modern SAS controllers are able to utilize SAS expanders as they are a popular feature in SAS deployments.  A SAS expander works in a somewhat similar way to a network switch whereby a single 4-lane SAS cable can be used from the RAID card or HBA and connected to the expander with more than 4 ports populated. In the case of the Intel RES2SV24, there are six SFF-8087 ports which means that there are 6x 4 = 24 ports avialable. With four used to connect to the HBA or RAID controller, that allows for 20 ports to be used for disk drives with four ports used as a connection to the SAS HBA or RAID controller.

The primary use case for this expander is either in-system to turn 4 ports of a SAS controller into 20 usable disk ports or to use in an external JBOD enclosure. The first use case allows for a less expensive 4 or 8 port controller to be used yet for an additional 20 drives to be connected to that controller. The second use case is often to aggregate disks in a JBOD chassis and connect them using fewer external cables.

A primary benefit of this card is that it has the ability to be powered via a 4-pin Molex power connector. That means it does not require installation in a motherboard PCIe slot. Another benefit is that unlike previous generation expanders, this Intel unit can allow both SAS and SATA 6gbps linking.

If you have questions on how SAS expanders work (in more detail) feel free to visit the fourms and there are resources linked below on how to use cards such as these. At the price of $72-87 shipped many of the forum members have been getting them for 25% of the normal pricing.

How to get the low price

General retail pricing on the Intel RES2SV240 is between $230 and $300 USD. STH readers have been purchasing these for as low as $60 + 12 shipping.

To get this price:

1. Go here for the auction that lists the Intel RES2SV240 for $160 + 12 shipping. This is already a great deal on a new SAS 2 expander
2. Best offer for between $60 and 75 + 12 shipping seem to get accepted
3. Await acceptance of the best offer and adjust if required

What else you will likely want

Using this SAS expander one has two options. The first is to use it in an existing system. The second is to use it in a dedicated disk enclosure. If it is added to an existing system, you will need SFF-8087 to SFF-8087 cables to connect the Intel SAS expander to your SAS2 HBA or RAID controller. If you are trying to make your own JBOD/ DAS expander chassis, you will likely want to pick up a Supermicro JBOD Power Control Board – $50 on Amazon. We had a piece on the JBOD power control board here. The board allows you to power on/ off the chassis without a motherboard installed which is perfect for an expander JBOD chassis.

Other SAS expander resources

STH has had a long history of providing SAS expander resources. Here are some of our 2010 resources using the then popular HP SAS expander to build large SATA JBODs:

• SAS Expanders, Build Your Own JBOD DAS Enclosure and Save – Iteration 1
• SAS Expanders, Build Your Own JBOD DAS Enclosure and Save – Iteration 2

The HP expander in those articles required PCIe power. This Intel RES2SV240 can use a standard Molex 4-pin power connector so it is recommended that one uses the Intel expander and the Supermicro JBOD board these days.

Other helpful resources include Jeff’s External SAS/ SATA Disk Chassis Wiring mini-series which can help you understand how to wire external SAS/ SATA chassis:

• External SAS/ SATA Disk Chassis Wiring – Part 1
• External SAS/ SATA Disk Chassis Wiring – Part 2

Overall, this is a great deal that hopefully many folks will be able to take advantage of. SAS 3 expanders are out, but for most SATA JBOD applications, these newer SAS 2 expanders work well.