Completed Build, Performance, and Conclusion

The Define S permits a very clean build with minimal effort given the generous space and excellent cable routing support. This build seems far too small for this enclosure, but were this my full-time case I'd appreciate the room for future expansion.

I opted for my usual single-SSD storage solution for this build, but the addition of more hard drives would not have presented a problem for cable management given the amount of room behind the back panel.


The Define R5 not only had outstanding low-noise performance when tested (though I did use rather low-end hardware at the time), but also has very efficient cooling; and with the Define S I was expecting similar performance. With this review unit containing a large side window I wondered what kind of impact this might have on noise output, though it could positively impact temps with less insulating material present.

To measure temperatures I ran an identical setup in both the Define S and the Define R5, using a Corsair H105 AIO liquid CPU cooler (mounted to the front fan mounts). In both instances the stock intake fan was removed from the front, with the stock exhaust fan left in place on the rear mount to allow for proper airflow. Fans on the H105 were positioned to push, and air was directed in from the front for better CPU cooling. Of note, as the GPU in this setup is MSI’s AMD R9 290 Lightning card we should have a good test of case airflow since a lot of warm air is going to be forced into the enclosure during benchmarking runs.

Test Platform
Processor Intel Core i7-4790K
Motherboard ASUS MAXIMUS VII GENE (mATX Intel Z97)
Memory G.Skill AEGIS 8GB 1600MHz DDR3
Graphics Card MSI Radeon R9 290X Lightning
Storage OCZ Vertex 460 120GB SSD
Cooling Corsair H100i GTX, Corsair H80i GT, Corsair H105, Noctua NH-D14 SE2011 (with NM-i115x)
Power Supply SilverStone Strider ST-1000P 1000W Modular PSU
OS Windows 8.1 64-bit

Temperatures results from the following tests were obtained using RealTemp to monitor the CPU and GPUZ to monitor GPU temps. CPU loads were generated using Prime95 with a 5-minute torture test simulating a worst-case load temperature for the H105 cooler. GPU load temps were created using the Unigine Valley benchmark with the “Extreme HD” preset, and after the card was allowed to warm up the maximum temperature was recorded during a benchmark run.

As you can see the Define S is extremely similar to the R5 with temperatures. As in, nearly identical once we factor in a margin of error of even +/- 0.5 °C.  The only area where there was a noticeable difference was in CPU load temps, which somewhat surprisingly ended up higher with the Define S by a couple degrees. This could be attributed to the slight spacing and screen filter differences from the revised front panel, though I may have just been seeing the H105's PWM fans not reacting to such a slight increase in temps and simply not increase fan speed accordingly. Regardless, these results were close enough to call it a draw, but the edge still goes to the R5 by the numbers.

Next we look at noise results:

Another very similar set of results here. The new Define S is the overall winner, and it seems that the side window does very little to raise overall noise. The more open internal layout of the Define S seemed to allow the fans in the system to spin at slightly lower RPM much of the time, allowing an overall very slight reduction in noise from the Define R5.


My initial impression of the Define S began with the inevitable comparison to the Define R5. And while it might look identical from the outside there is a little more than just a revised layout at play here. Namely, cost. At $119 I still felt that the Define R5 brought enough to the table that it was worth the investment. The new Define S is virtually identical other than internal storage, and if you can live with a 3 hard drive, 2 SSD limit then the changes only add to the experience given the seemingly limitless room for cooling, huge graphics cards, and the longest power supplies. But all of this comes at a price, right?

Turns out getting a little less storage gains not only flexibility, but value. The retail price of the Define S as reviewed  (with side window) is just $89.99. So, $30 less than the R5 for almost the same enclosure? What gives? Well, directly comparing the two I noticed the side panels were a bit thinner, and gone is the latch mechanism to open the access panel so the doors simply slide on. This isn’t to say that the new case feels cheap, but it is noticeably lighter overall while still retaining a rigid frame and premium feel. That's...pretty much it, actually! The removal of the hard drive cages is intrinsic to the design of the Define S, and shouldn't be counted against this version since the R5 is available for those with bigger storage needs.

Overall the new Define S has the same premium yet understated look of the R5, and it makes a lot of sense for someone interested in a full custom liquid cooling setup - though the fully open interior certainly makes for an easy build process with or without a custom loop. There is a great deal of room behind the motherboard tray as well, allowing for the same effortless cable routing as the Define R5 and making use of the same pre-fitted Velcro straps to hold things in place (one of the best design attributes in my opinion, and I wish all cases had this).

The storage solution is certainly innovative, and I wouldn’t be surprised to see more enclosures move to something similar. The result of this move is to create an interior so vast that it begs the question: does a computer case have to be this big anymore? I think the answer is becoming a resounding “no”. Moving away from the minimum size dictated by 5.25” wide optical drives, large air coolers, and 3.5” storage would allow for most systems to shrink to the size of a gaming console. For now though, you can’t go wrong with the Define S. With this kind of flexibility to go along with sophisticated styling, quiet and cool performance, and a very reasonable price tag, I can’t find anything to complain about here.

Bottom line: If you’re interested in custom liquid cooling or appreciate the options provided by a wide-open interior layout, the Define S from Fractal Design is an excellent choice. It's constructed well, looks great, offers great thermal performance and low noise, and it’s priced competitively at $89.99. In short, I highly recommend it!

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