We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.

[nextpage title=”Introduction”]

Unicorn from Sigma is a steel mid-tower case with a dark transparent side window and four 5.25” bays, two external 3.5” bays, five internal 3.5” bays for hard disk drives (four available in a removable hard disk drive cage), four fans (two 80 mm and two 120 mm) and aluminum door. Let’s take an in-depth look at this new release from Sigma.

Sigma Unicorn CaseFigure 1: Sigma Unicorn case.

Sigma Unicorn CaseFigure 2: Sigma Unicorn case.

This case has a front door, but only its front-most part is made of aluminum, the back part is made of plastic. On top of this door you can find the two LED’s (power and HDD activity) and the two switches (power and reset).

Sigma Unicorn CaseFigure 3: Front door, half aluminum, half plastic.

In Figure 4, you can see the front panel from this case with its door opened. As you can see, it has four 5.25” bays, two external 3.5” bays and one 120 mm fan cooling down the hard disk drive cage.

Sigma Unicorn CaseFigure 4: Front panel.

The main problem with this case is that the audio and USB connectors can only be accessed when the case door is opened. If you have a headset with microphone to play online games with VoIP function or to talk on Skype, you will have to leave the case door permanently opened – or at least half-opened. This is simply ridiculous.

This case doesn’t have an eSATA port or a FireWire port, features easily found on competing cases. On the other hand the two USB ports available are located far away from each other, allowing you to use two “fat” USB devices (like pen drives) without one device blocking the installation of the other.

In Figure 5, you can see the rear panel from this case, which has a very traditional looks, with the power supply on the top, seven slots for daughterboards and one 120 mm fan.

Sigma Unicorn CaseFigure 5: Rear panel.

Let’s see how Unicorn looks like inside.

[nextpage title=”Inside Unicorn”]

The way you open this case is different from all cases we reviewed so far. Instead of removing some screws or pressing a latch on the rear side of the case to remove its side panels, the side panels are removed by pulling a latch located on the top part of each panel, see Figures 6 and 7 to understand. You can remove both panels and the motherboard tray comes attached to the right panel. After the case is opened the side panels continue attached to the case.

Sigma Unicorn CaseFigure 6: Opening Sigma Unicorn.

Sigma Unicorn CaseFigure 7: Opening Sigma Unicorn.

The first thing you should notice is that the left side panel is dark transparent, not clear transparent as it usually happens with cases with a transparent side window. This panel comes with an 80 mm fan attached to it, which glows red when it is turned on. The left panel also has a side venting mesh, which is used by another 80 mm fan that is attached to the case on top of the daughterboards, helping dissipating the heat generated by the video cards. All fans from this case use a standard 4-pin peripheral connector, meaning that they don’t have speed control and you also can’t monitor their speed.

Sigma Unicorn CaseFigure 8: Side fan that glows red when it is turned on.

In Figure 9 you can have an overall look inside Unicorn. On the left side you can see the rear 120 mm fan and also the 80 mm fan on top of the place where the daughterboards will be located. Next to this fan you can see three plastic mechanisms to firmly hold daughterboards in place, in order to avoid them from getting out from their slots when you transport your computer, which is very common to happen especially with long and heavy video cards.

Sigma Unicorn CaseFigure 9: Inside Unicorn.

[nextpage title=”Inside Unicorn (Cont’d)”]

The middle support can be easily removed by pressing a plastic latch located on the left end; you don’t need to remove any screw. You can swing it to your direction like a door or you can completely remove it but pulling it up.

Sigma Unicorn CaseFigure 10: Removing the middle support.

In Figure 11 you can have a better look at the 80 mm fan that is attached to this support and also the three plastic mechanisms to hold daughterboards in place. You need to adjust the height of each mechanism until you see that they are really holding each daughterboard in place.

Sigma Unicorn CaseFigure 11: Fan and holding mechanism for daughterboards.

As we briefly mentioned, this case has a removable motherboard tray. This tray comes attached to the right side panel, but you can remove it from the panel, if you want to. We liked this tray as it helps a lot the process of building your PC. Part of the rear panel is also attached to this tray. The slots for installing daughterboards don’t use any kind of screwless mechanism to hold daughterboards, so you will have to use the regular screws here.

Sigma Unicorn CaseFigure 12: Motherboard tray.

On the right side of the case there is a plastic frame for you to install an additional 80 mm fan that doesn’t come with the product. Note that the right panel has venting holes for this fan. The goal of this fan is to provide extra cooling for devices installed on the three 3.5” bays located outside the hard disk drive cage. In most configurations you will have only a floppy disk drive installed there – if you still use this kind of Stone Age device.

Sigma Unicorn CaseFigure 13: 80 mm fan holder on the right side of the case.

[nextpage title=”The Disk Drive Bays”]

This case has four 5.25” bays, two external 3.5” bays and five internal 3.5” bays, with four of them located inside a removable hard disk drive cage, see Figure 14. All bays from this case use screwless installation mechanisms that really don’t require screws, except if you wish to install hard disk drives on the two external 3.5” bays. As you can see in Figure 14 they use a different mechanism that isn’t compatible with hard disk drives. If you want to install hard disk drives there you will need to remove the plastic mechanisms and use regular screws. The maximum number of hard disk drives you can have with this case is six or seven, if you don’t have a floppy disk drive.

Sigma Unicorn CaseFigure 14: Bays available on Unicorn.

The hard disk drive cage can be removed by removing a thumbscrew and pulling a lever. To remove it you first need to slide it to a 45° angle – which may help you to install hard disk drives without needing to remove the cage from the case.

Sigma Unicorn CaseFigure 15: Sliding the hard disk drive cage.

Sigma Unicorn CaseFigure 16: Hard disk drive cage outside the case.

[nextpage title=”The Disk Drive Bays (Cont’d)”]

To install hard disk drives in the cage you need to first install two metallic rails to each drive. These rails are located inside a small toolbox located below the hard disk drive cage.

Sigma Unicorn CaseFigure 17: Toolbox with screws and the hard disk drive rails.

Sigma Unicorn CaseFigure 18: Hard disk drive with rails installed.

Sigma Unicorn CaseFigure 19: Hard disk drive installed inside the cage.

The installation of optical drives, floppy disk drives and a hard disk on the 3.5” internal bay located outside the hard disk drive cage is very easy. First remove the cover located in front of the bay you want to use (step not necessary for installing the hard disk drive), remove the screwless installation mechanism twisting its knob counter clockwise, slide the drive in the bay, place the plastic installation mechanism back in place and then turn its knob clockwise. That’s it.

[nextpage title=”Main Specifications”]

Unicorn case main specs include:

  • Application: ATX and smaller form factors derived from this one.
  • Material: Zinc-coated steel (SECC).
  • Power supply required: Optional 500 W unit, not available on the reviewed model.
  • Available colors: Black.
  • Side panel: Dark transparent.
  • Dimensions: 18” x 8 1/2” x 21 3/4” (45.7 cm x 21.6 cm x 55.25 cm) (H x W x D).
  • Net Weight: N/A
  • Bays: Four external 5.25” bays, two external 3.5” bays and five internal 3.5” bays (four available in a hard disk drive cage).
  • Expansion slots: Seven.
  • Fans: One 80 mm fan on the side panel (red), one 120 mm fan on the rear, one 80 mm fan above the daughterboards and one 120 mm fan on the front.
  • More Information: https://www.sigmaproduct.com
  • Average price in the US*: USD 100.00.
  • Researched at Newegg.com on the day we published this review.

[nextpage title=”Conclusions”]

Sigma Unicorn is a very good case, with a sturdy construction and no sharp edges where you could cut your hands and fingers while building your PC. It provides a different opening mechanism and a removable motherboard tray, which always facilitate the computer building process.

It also has a very good number of hard disk drive bays – six or seven, if you don’t use a floppy disk drive –, which is a point we always criticize in high-end cases; some cases cost the double of Sigma Unicorn and still have only one HDD cage supporting only four drives.

Its screwless installation mechanisms are really screwless. Some more expensive cases still require you to use screws to attach rails to the hard disk drives or to the optical drives, which isn’t the case with Unicorn. There is one exception, though. If you decide to install hard disk drives to the external 3.5” bays you will need to use regular screws to fasten the drives, as the mechanism available on these two bays are only compatible with floppy disk drives.

The only problem we see with this case is its price because at Newegg.com you can find NZXT Tempest costing the same thing (after a $10 mail-in rebate), and this case from NZXT is, in our opinion, a better product, and that is why we are giving Sigma Unicorn our “Silver Award” and not our “Golden Award.”

This case isn’t perfect, but for its price range we can’t complain very much about them. If you are a picky user, however, maybe these flaws will disturb you and make you to decide buying a different product. Since Sigma Unicorn is in the same price range as NZXT Tempest, we also included a small comparison between the two on the list below.

  • Its front door isn’t 100% made of aluminum; half of it is made of plastic. NZXT Tempest doesn’t have a front door.
  • The audio and USB front connectors are located on the case front panel, behind the front door. If you install devices on these connectors you can’t close the door. This problem doesn’t happen with Tempest as it doesn’t have a door.
  • It doesn’t have an eSATA port. Tempest has.
  • It doesn’t have a FireWire port, and Tempest also doesn’t have one.
  • No screwl
    ess mechanism for fastening daughterboards to the case. Same thing with Tempest.
  • Less fans than NZXT Tempest. Unicorn has two 80 mm fans and two 120 mm fans. Tempest has four 120 mm fans and two 140 mm fans.
  • Fans use regular 4-pin peripheral connectors, not allowing you to control or monitor their speed. The fans that come with Tempest use a motherboard 3-pin connector, allowing you to monitor their speed.
  • Unicorn can hold up to ATX motherboards. Tempest allows the installation of bigger extended ATX motherboards.
  • NZXT Tempest allows you to install radiators from water cooling solutions that are based on two 120 mm fans inside the case. Sigma Unicorn doesn’t.