The Corsair Obsidian 900D is a large full format tower with extensive water cooling support.  It replaces the old 800D design as the top of the line Corsair case and was nicknamed “Godzilla” in development because of it’s large size.  The goals of the design were to fix all the complaints that users had with the 800D while creating the ultimate mainstream water cooling case.  I mention mainstream for two reason.  The first is that this does not replace boutique cases and nor is it meant to compete with them.  It does not cater to the ultra high end, but to “just” the very high end.   The problem with focusing on the high end PCs as we do at ExtremeRigs is that after some time a large water cooled multi-gpu system can seem very normal, when in reality it’s at the very high end of current PC offerings.   The second is that the mainstream may define more than we may at first expect.  The 900D is of course aimed towards the “Built Not Bought” crowd, but it’s also designed to be sold to the larger mainstream through boutique and custom PC builders.  Companies like Origin PC were very quick to switch their high end PC offerings to use the 900D as soon as it was launched.  As we look at the case design these two factors will be seen to have influenced many parts of the design.

A little history…

The 900D was launched as the first of the Obsidian line refresh, preceeding both the very competitively priced mATX format 350D and the full format 750D case.  The case is made in China of steel and plastic and comes with zero customizable options.  There is no reverse ATX option, there is only one color available (black) and there are no window options and really somewhat limited options.  The design is obviously made to reduce manufacturing overheads as much as possible and therefore maximize profit.  This is particularly important when you are targeting boutique PC vendors as they will be buying in bulk and wanting a discount that will eat into the normal profit margin.  Having said all of this, this one size fits all really does cover 95% of the serious water cooler’s needs.  If we ignore the boutique case designs such as CaseLabs, Mountain Mods and LittleDevil then there are very few cases that directly compete with the 900D.  The obvious competitor is the aging Silverstone TJ07 which being made of Aluminum is not only pretty expensive but doesn’t support as much radiator area or larger motherboards.  To be honest this was the case that Silverstone should have made it if it hadn’t have got lost along the way.


The critical specs for the 900D are really the following:

Overall Dimensions: 25.6″ x 9.9″ x 27.2″

Weight: 41lbs

Motherboard Support – ATX/eATX/XLATX/HPTX and many more…

Radiator options:

480/420 at the top

480/420 at the bottom, side mounted (if you give up a 2nd PSU)

240 at the front (if you give up the drive bays in the main chamber, and a 360 if you don’t mount a large radiator in the base)

120 at the back above the IO plate (bear in mind this will probably get hot air and is most likely a waste of time)


I would recommend 480 radiators over 420 as the difference in surface area is only 2% and the 120mm fans have more options.

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  1. Great review. I have been looking for a long term review for the 900D. I have heard problems with production quality, like bits snapping off. But you give no mention of that so I’m assuming these are isolated incidents.

    • Hey Terry – Yes I haven’t seen problems in the long run with anything failing. Most complaints I’ve seen were things being delivered with something broken. There’s definitely improvements that can be made and corners that were cut to save costs, but for the non-msrp price it’s a great deal!

  2. Like the 900D. But – 480 rads can be obstructing to the upper bay as the rad will intrude on optical drive lengths / area. For this reason I swapped over to a 420 up top. Plenty of room all round and leaving many other options open, so I would disagree on the 480 recommendation up top.
    Had to remove the lower intake fan as well to accommodate the 480 which is 60mm deep as the rear chamber just impinged on the fan mounts – using Alphacool nexus 480 x 60 unit with the 420 x 60 up top. Also a 140mm below as well. This aside, a joy to work in but still not the same as my lianLi 2120 workstation unit. may well look at the boutique brigade next time..