TL;DR: if you want a SuperMicro SC836 Chassis look on eBay for the Dell CT-040 instead, continue reading for some caveats around that.

I’ve been in the market for a SuperMicro SC836 chassis for a while now, seemed the logical upgrade path from my existing NAS solution which uses a full-tower case with two four-in-three hotswap adapters in it (units which contain 4x3.5” sleds and fit in the space of 3x5.25” bays, though some… pursuasion was required with respect to the sheet metal inside the case).

The SC836 is a nice 3RU rack mount chassis with 16x3.5” hotswap bays on the front and (optionally, for some types anyway) 2x2.5” hotswap bays on the back, it comes in a variety of flavours as far as (redundant) power supply capacty and backplane type. The most popular flavour is the SC836BE16 which has a (single-channel) SAS expander backplane for the 16 front bays. This is what most people go for when they buy one, because it allows you to feed all the drives with a single HBA, even if it’s not neccessarily the “best” option technically speaking.

After investigating it a few times with several local suppliers and being unable to justify spending upwards of $AUD1500 for a bare chassis this has been put on the backburner several times over the past several years.

I had a few hits on my eBay saved search over the years but none were local and shipping to Australia being what it is, they weren’t really viable options. But recently serendipity struck; I had some extra cash from a contract job and I had a search come through for a listing purporting to be an SC836BE16-920RB [sic] (close inspection of the images and specs disagreed with that but it was still suitable for my purposes) and it was in SA, so after a bit of back and forth with the seller I went ahead and bought it for around $700 shipped.

The unit was actually Dell branded, model number CT-040 and further searches (of course, after I paid, but that’s life) found several AU listings for these as low as $400… But there are some caveats you should be aware of purchasing one of these (nothing too drastic).

A quick note on SuperMicro chassis numbers;

  • SC836 - Chassis Model
  • B - Chassis Subtype
  • E16 - Single channel, 16 bay expander backplane (the dual-channel version is 26).
  • R - Redundant power supplies
  • 920 - 920W power supplies
  • B - Not really sure, all bar one the chassis numbers in this model end with B.

The CT-040 is actually a custom variant, in “proper” terms it would be an SC836TQ-R1200B which doesn’t exist in this model line.

  • SC836 - Chassis Model
  • — - No subtype
  • TQ - Direct connect backplane (there are 16 SAS (SATA compatible) connectors on the back of the backplane).
  • R - Redundant power supplies
  • 1200 - 1200W power supplies
  • B - Assumed

There are two major caveats as a result of this;

  • Since it’s a “TQ” backplane you need 16 individual channels of SAS/SATA to feed it. This can be achieved by using multiple HBAs/RAID controllers with fan-out cables (preferred) or a single HBA/RAID controller with an expander card (IBM and HP SAS expander cards can be had cheap on eBay, though I’ve never tried to use one so YMMV).
  • Since it’s NOT a “B” chassis the 2x2.5” rear-mount hotswap bay kit doesn’t fit in it (not without some… adjustment anyway. Keep an eye out for my next post for the fix for that).

It also doesn’t include the “air shroud” listed in the SC836 chasssis manual, but even with two E5540’s and 48GB of RAM mine doesn’t run overly hot, if you’re worried you could probably source one from SueperMicro or hell even 3D print something.

Besides that it’s entirely usable just like a new bought SC836 would be, it fits normal ATX motherboards (though you might need some cable adapters, and a fan controller for the 5 chassis fans) and supports 16 hotswap bays, I'd prefer it had 80PLUS Titainum supplies but 80PLUS Gold is still pretty good, and theoretically I should be running in the "maximum efficiency" pretty much all the time anyway.