ICY DOCK MB994SP-4S Mobile Rack Review

As with Icy Dock’s product description, the MB994SP-4S is designed for high intensity use in high-workload situations. Whilst I am not the target audience of this product, that doesn’t mean it was of any less use to me. I am an enthusiast. I loathe cable clutter. The more free room, the better.

Installed in the Icy Dock MB994SP-4S is one Plextor M3 128GB SSD and one Seagate Momentus XT 7200rpm 750GB SSHD. As previously mentioned, installation is very easy, and will take approximately five to ten minutes depending on your skill level.

Because the Icy Dock is powered by two MOLEX connectors, I was able to connect just one MOLEX cable to my power supply – it has 3 MOLEX connectors on it, so two went to the Icy Dock, and one went to my fan controller. No need for SATA power cables. Whilst maybe slightly niche, this was a huge benefit to me and my meticulous, bordering on OCD cable management practices.

My Seagate Momentus XT SSHD was at 28°C whilst being benchmarked by ATTO (these results are not included due to the nature of an SSHD – I only benchmarked it for the thermals.) This shows the rear 40mm fans are serving their purpose and pulling air through the rack, effectively cooling the drives. You can be confident that your drives aren’t going to burn up in the enclosure, even if they’re running at 15000 RPM.

I ran a total of three benchmarks on my Plextor M3 128GB SSD.

I wanted to see if the MB994SP-4S caused a performance difference, so I ran a series of benchmarks with my SSD both in the rack, and connected traditionally outside of it.

The HDTune read benchmark reads sequentially from the drive and records the results as the filesize grows. The HDTune File benchmark tests a 500MB file, both read and write, and the secondary test also shows the drive performance during different block intervals. ATTO benchmarks both the read and write of the drive with different block sizes.

Inside the Icy Dock MB994SP-4S

HDTune Read Benchmark:


HDTune File Benchmark:



ATTO Read/Write Benchmark:


Outside of the MB994SP-4S

HDTune Read Benchmark:


HDTune File Benchmark:



ATTO Read/Write Benchmark:


According to HDTune, being out the rack gives the SSD an ever-so-slight boost in performance.

The story is the same for ATTO, where there is a slight performance increase when the drive is connected traditionally instead of inside the MB994SP-4S.

When the file size is smaller, the gap does seem to widen somewhat.