Review of hot-swap cage for LFF drives: Exegate HS335-02

Exegate offers inexpensive server enclosures, power supplies and Hot Swap cages for those who just need to assemble a server without any frills. Today we are testing a classic Hot Swap cage with 3 compartments 3.5/2.5 inches, installed in two 5.25-inch compartments. This cage can be installed both in rack enclosures with a height of 3U, and in desktop/floor enclosures designed for assembling small storage or servers for working with large amounts of data. The Exegate HS335-02 model is designed to install SATA drives, but it will also work with SAS disks.

In general, 3.5-inch cages are purchased, as a rule, to create large data arrays on 3.5-inch SATA disks, and 2.5-inch drives are installed in some special cases, for example, when you need to build an array on an SSD, and you can't turn off the server and change the cage. Basically, SATA drives are used to reduce the cost of the machine in cases where a motherboard is used without an integrated SAS controller, and there is no budget for a discrete adapter. For this reason, such cages are equipped with conventional SATA ports, and since usually SATA cables are bundled with each motherboard, then the device can not be equipped with them, which again has a positive effect on the price.

The Exegate HS335-02 model has an all-steel body with an aluminum front panel. Please note that there is a recess on the side wall for the guide dividers of the 5.25-inch housing compartments, but in this case it is a stiffening rib that reduces the vibration of the device. In modern cases, as a rule, the 5.25-inch compartments are not separated and do not have any guides - the Exegate HS335-02 cage will be installed in them without problems. But in some cases, especially old ones, there were short shelves between the compartments on which you could put a DVD/BD drive without screwing it to the walls, and this cage won't fit into such cases, they need a model with a through-cut along the length, such as Exegate HS335-01.

The closed body creates a kind of wind tunnel in which the air enters strictly from the front, through the front panels of the trays, passes through the discs and is ejected from behind into the body. Since most disk cages are cooled at negative pressure, it is always better that the case does not have slots and holes on the sides, bottom and top, which is what we see here. That is, it does not matter at all what configuration your case is, rack or desktop - it will not affect the cooling of the drives in the cage in any way. This is the advantage of closed cages over open ones with mesh sides.

Power is supplied via a pair of 4-pin Molex connectors connected in parallel. Even one plug, upper or lower, is enough for all three disks to work. I want to draw attention to the fact that 4-pin Molex connectors exclude the manifestation of a problem with the Power Disable Feature, which can greatly spoil your nerves if you buy a SATA-600/SAS-12 HDD on the secondary market (read more about why the new HDD may not turn on in our article on the fight against Power Disable Feature).

A fan is connected to the lower power connector with a through cable. The Exegate HS335-02 disk cage itself does not track its operation and has no speed adjustments, which is not surprising, since this is a budget model. On the other hand, the own logic of cages with a built-in "alarm system" is usually limited to giving a sound signal and turning on red LEDs: the fan stops - the cage beeps and glows like a Christmas tree. It was interesting in the late 90s or early 2000s, but in the era of IPMI monitoring and notifications via Telegram, I think that on Hot Swap cages the fan should be changed first and connected to the motherboard. And the less the disk cage resists this with its squeaks and flashing lights, the better. Therefore, in this case, the lack of speed adjustments is a plus for me.

The included fan is a simple, 2-watt one: the DFG8025S12M model from the little-known manufacturer DFG. Its specifications could not be found, but judging by the marking, sliding bearings characterized by low vibrations are used here. Fans with ball bearings should not be installed directly on the disk cage body, at least without complex vibration coupling, as is done in HPE and Lenovo branded servers. As I wrote above, I am of the opinion that the fan on the disk cage should be changed immediately upon purchase, and Exegate HS335-02 is no exception. Its dimensions are standard here - 80x80x25 mm, so you can easily replace it with a more expensive one with PWM adjustment, but more importantly, you can do this without removing the disk cage from the housing: the screws are large and unscrewed with a standard phillips screwdriver, they pass through the entire length of the fan, so they do not fall out and are not lost somewhere.that's in the back of the server. And do not think that all this is unimportant: yes, such moments are trifles, but it is from them that the total time for troubleshooting is made up. For example, in the ICY Dock MB508SP-B cage we considered, the fan is screwed with two small screws through the inner ears, so that it can only be unscrewed with a thin screwdriver, and then remove the screw from the screwdriver without removing it from the fan. It happens that in many similar models, to replace the fan, you need to disassemble the entire body of the device, removing the rear plastic part, that is, take the server out of operation for at least an hour, and here the same procedure can be carried out in 10 minutes. Of course, if the fan was mounted on latches, it would be even better, but I did not come across such a solution in separately sold disk cages.

The fan is shifted slightly to the left relative to the center, so it cools both 3.5-inch and 2.5-inch drives equally well, because if it stood in the center, then when installing an SFF HDD or SSD, the airflow would pass by the drives.

Let's look at the Exegate HS335-02 trays: they have a steel base, an aluminum handle and plastic sidewalls with a latch. On each of the trays there is a small lock for a triangular key to protect against involuntary disconnection of the disk by accidentally pressing the latch. Such locks do not protect against theft, and as a rule, they are easily opened even with tweezers. The locking mechanism is a little unusual: you need to do two opposite movements at once to close the tray: push the handle forward and pull the latch back. The discs are opened by the usual pulling of the latch with the index finger.

The bottom of the trays is flat, without a pronounced gap for the passage of air flow. For modern hard drives, this is no longer a problem, since in them the controller board is located facing "inside", and the heat from the chips is transferred directly to the HDD enclosure through a thermal pad.

Inside the Exegate HS335-02 case, the guides for disk trays are located along the entire length, so you will not be able to skew the HDD during installation, even if you really want to: the trays slide quietly and smoothly, thanks to the contact of plastic sidewalls and steel housing. But there is no individual vibration coupling of hard drives here, and this is an unpleasant minus, perhaps the only one in the entire cage design.

The backplane is generally ideal from my point of view: there are no electronic components here, except for the LED power/activity indicators and the resistors required for their operation. There are no constantly drying capacitors or any controllers, so there is absolutely nothing to break down here. I don't know at all why someone puts capacitors on these boards in other cages - hard drives usually have built-in tantalum capacitances to reduce power supply voltage ripples, and duplicating them on the cage creates nothing but an extra point of failure.

Ventilation holes, of course, could be wider, but given the fact that voracious LFF HDDs at 10 and 15 thousand RPM are firmly out of use, the existing ventilation should be enough, which we will find out now.

Testing of HDDs temperature

For testing, I used 3 Seagate Exos 7E8 (ST4000NM000A) hard drives connected to an Adaptec ASR-8405 RAID controller. A RAID-5 was created from three disks, which was loaded with random reading using the IOmeter program for 1 hour.

The test was carried out in two stages: in an open cage (disk rack), and in the tested Exegate HS335-02 at an ambient temperature of 25 degrees Celsius.

The temperature regime did not bring any surprises as expected: the cage copes well enough with cooling enterprise-class disks in the toughest mode for them.

Conclusions

We have a surprisingly successful disk cage in front of us, and don't be confused by its low cost. It is quite easy to maintain and devoid of possible points of failure, such as unnecessary controllers, beeps or indications.

the advantages:

a simple, one might say, clumsy design
4-pin power supply
no ventilation holes on the sides of the case
standard SATA ports
relative ease of replacing the fan

the disadvantages:

absence of vibration coupling between disks
impossibility of installation in cases with protrusions between 5.25-inch compartments
support for SAS disks is not declared

Without options, if you need a disk cage for SATA drives with a speed of 7200RPM or lower, as well as for SATA SSDs, the Exegate HS335-02 model is suitable for this role.

Michael Degtjarev (aka LIKE OFF)
08/02.2023