The PSU comes in a large box featuring a silver and grey background. At the front are a close-up of the unit's nicely designed fan grill and the series name in the top-right corner, inside a yellow frame. Right below it are a series of badges for the five-year warranty, semi-passive operation, Gold efficiency, and low-noise fan. The model number located under the aforementioned badges is given in large fonts.
This side has nothing worth commenting on.
Corsair provides a useful description of all connectors and their numbers on this side, and the description even includes cable lengths, since Corsair is familiar with the queries of users and reviewers. We wish more companies were as thoughtful as they are!
The rear has two graphs displaying the unit's efficiency curves with 230 VAC and 115 VAC power input, and the fan's noise output. According to the second graph, the fan starts to spin up after the load reaches 40% of the unit's maximum-rated capacity. We also found the power specifications table on the same side.
The PSU is surrounded by packing foam to ensure it reaches its user in pristine condition, regardless of shipping conditions. Corsair is generally very careful with their packages, which is to their own benefit since it reduces DOA (Dead On Arrival) products that would have to be RMAed—many DOA products are due to harsh shipping conditions and improper packages that provide insufficient protection.
The bundle includes the modular cables, a user's manual, a warranty leaflet, an AC power cord, enough zip ties, and a Corsair case badge. You will also get a product catalog, but our sample didn't include any fixing bolts for PSU mounting. Corsair apparently forgot to include a set since this is a review sample, but we, contrary to normal consumers, don't actually need them.
This is the optional Corsair Link cable you must purchase separately if you want to monitor the PSU's fan speed and +12V current output. Corsair chose not to include it in the bundle since it would increase the final price. Given the limited features Corsair Link provides to analog-controlled PSUs, we think they made the right choice. The Corsair Link cable attaches to a USB header on your mainboard, and you have to download the Corsair Link software to monitor fan speed and +12V current output. We wish they would also provide a USB adapter for connection to a normal USB port, which would spare us a bunch of trouble since we don't mount PSUs into a chassis, but use Chroma load stations instead.
The RM850's finish is quite good, and its external construction quality looks nice, leaving us with a good feeling in regards to its internals. External quality means a lot to most users, and Corsair is thankfully aware of this. The design also stands out of the crowd because of its rounded corners and the nicely designed fan grill, which is Corsair's trademark. The small on/off switch at the front is installed next to the AC receptacle, and a honeycomb grill provides a route for hot air to escape while the unit's fan is in operation. The decals on both sides are nothing fancy; they don't spoil the good looks of the unit. The rear has the fully modular panel of the PSU. Near the top-left corner is the C-link connector through which you connect the PSU to a mainboard's USB header, which would allows you to monitor both fan speed and +12V current from your desktop. Corsair Link surely doesn't provide the same functionality as with Corsair's digital units (the AXi series), but it still leaves users with two features the competition fails to offer. The only downside is that you will have to buy the adapter separately.
The RM850 is 18 cm long, leaving it with quite large dimensions, but its fully modular design makes it look smaller than it really is.
All cables are stealth and flat, which will make installation and cable management easy. These attributes also improve internal airflow, at least compared to classically round, sleeved cables. We think that flat cables are the way to go with PSUs. As for whether they are all-black or normally colored: we don't care, but many users prefer black cables because they blend in well with a black interior. Finally, hardcore modders usually make their own cables, or prefer individually sleeved cables which look nicer, but those also occupy more space, are trickier to route inside a case, and cost way more.