iStarUSA BPN-350SAS-Black 3x 5.25″ to 5x 3.5″ SATA SAS Trayless Hotswap Backplane


As one’s storage needs increase, eventually even large 4U server cases need to pack higher hard drive densities in order to fit all of the devices needed. In the test server’s Norco 4U case I quickly realized that the standard drive bays would not be sufficient. I purchased three iStartUSA 5-in-3 SAS/SATA backplanes, one for the main system and two for the Windows Home Server all in the hope that I could increase drive densities. Not all would go smoothly…

The iStarUSA BPN-350SAS-Black allows for five 3.5″ SAS or SATA drives to be installed in three 5.25″ bays. This allows for above average storage densities which means that my Windows Home Server can hold ten 3.5″ drives in six 5.25″ drive bays. Another feature is that these enclosures are trayless, meaning one can insert a bare SAS or SATA drive directly into them. Each of the five slots has a lock to prevent accidental opening. I found it was very important to close this lock as the drives, upon insertion, are spring loaded to “pop” out if the door is opened. Furthermore, the doors did not latch in an overly secure fashion. As a result an accidental nudge of a door while inserting another drive could mean that a door opens and a drive pops out. For those that run Raid 5 or 6 with multi-terabyte arrays, an accidental drive pull can mean hours upon hours of rebuilding.

On the units back, it has ten SAS/SATA style connectors. Five are labeled as primary, five are considered secondary. For most users, only the primary ports will be used. The secondary ports are mainly for those that are installing dual channel SAS drives. Also on the rear panel are two four pin power connectors. This is great because it runs both the fans and the five drives using only two connectors. On the other hand, these connectors are spread apart quite a bit. As a result, some power supply cables will not be able to reach both connectors on this backplane with sequential four pin connectors coming from the power supply. This is not a huge issue, but it may be one for some users.

All the above taken into account, the iStarUSA BPN-350SAS-Black would be a great unit, except for the fact that spinning 3.5″ drives generate heat. Using five 1.5TB Seagate 7200.11 SATA drives the temperatures hold constant at 54C to 56C with all drives installed and in operation! The picture is virtually the same with three Atlas 15k.5 300GB SAS drives installed in positions 0, 2, and 4, leaving one space between them. I attempted twice to install 500GB drives, one Western Digital, one Seagate, inbetween two of the drives and both 500GB drives gave SMART errors or failed within days due to excessive heat. The enclosure does have two 60mm fans installed, and the fans are loud. However there seems to be some airflow issue as the high density of drives seems to not get cooled by the two fans. Possible suggestions to fix the design that one can see rather immediately may be to add a single large fan in the unit’s rear instead of the two smaller fans. Also, the doors at the front of the unit could use some ventilation openings to let air be sucked from the front of the unit to the rear. Until these changes are made, this product should be used with caution.

With that being said, I have been using two of these units, each with five 7,200 rpm drives in them for the past 6 months and have not had one of these drives fail. It seems like the 15,000 rpm SAS drives generate too much heat to be used with more than three drives in this enclosure. With that being the case, it seems rediculous to spend $100 on a loud 5 in 3 unit only installing three 15,000 rpm SAS drives versus just installing the drives in a one to one 3.5″ drive to 5.25″ drive ratio.


  1. Great article, except you need some pictures (even screenshots of the high temps).

    Also ridiculous was misspelled as “rediculous”


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