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Published November 8, 2018

If you haven’t already purchased either a Gemini PDA or a Cosmo Communicator from Planet Computers, you might be wondering which of these devices is best for you.  On the face of it, both devices are very similiar, both are PDAs and mobile computers, both run Android, Linux and Sailfish and both can make and receive phone calls.  We’re here to help with the decision of which one to buy and use, and we felt it was best to approach this question from an actual use case, and what you’d want from your device.

The little Differences – Draw

There are several areas where there really are little or no differences between the two devices.  In size, the Gemini is 17.14cm x 7.93cm x 1.51cm and weighs 320g.   The Cosmo is ever so slightly thicker, at 1.6cm (meaning there’s less than 1mm in it) and weighs the same as the Gemini.

There’s no difference either in the screen, the same 4,220mAh battery, the speakers, or features such as 4G (LTE) and Bluetooth connectivity.

There are slight differences in the internals though.  The Cosmo runs on a newer 2GHz, 8-core Mediatek processor, compared to a slightly older 2.6GHz, 10-core Mediatek chip in the Gemini.  At the moment we have no data on how performance between the two might differ, but the Gemini is hardly sluggish.  The Cosmo also comes with 6GB of RAM compared to the Gemini’s 4GB, and 128GB storage compared to the Gemini’s 64GB.  These last two might be of more importance to you, but both can have their storage expanded by MicroSD.

With the added inclusion of a biometric fingerprint reader, the extra memory and storage might edge this for the Cosmo, but it’s $200 more expensive at full price than the Gemini, and many buyers simply won’t need this functionality.

Phone functionality – Cosmo Wins

Let’s deal next with the most obvious difference between the two, telephony.  The Cosmo is designed to be used as a phone with the case closed, thus the external screen.  You can make calls to your contacts or by dialing numbers, and also receive calls.

With the Gemini it’s slightly less intuitive, as you can program the alert LEDs to tell you who is calling so you don’t have to open the case to answer, but you then have to remember what the different light patterns mean.  You can still answer calls with the case closed, but you have to open the Gemini to make a call.

Camera – Cosmo Wins

When it comes to the camera, the Cosmo is the clear winner.  Both devices include the same 5MP webcam camera internally, but the Gemini’s external camera is only a 5MP module with no flash, and also has to be purchased separately.  The Cosmo on the other hand has a 24MP external camera with flash, that can be operated in “selfie mode” with the case closed.

We don’t know yet what the quality of the camera and flash are like on the Cosmo, but if having an external camera is important to you, then the Cosmo is the clear winner.

PDA and Computing Functionality – Draw

When it comes to mobile computing and PDA functionality it’s a straight draw.  Both devices run the same software, though at launch they’ll run slightly different versions of Android, and they both perform the same functions.  Both devices will serve you well in a mobile computing role.

Linux – Gemini Wins

I won’t deal with Sailfish as it’s far from ready as a platform, but if you want a mobile device on which to run Linux then it’s a safe bet you’re after a mobile computer and don’t want, and won’t use the device as a phone.  Having a 4G (LTE) internal modem might be very useful, but here the Gemini is an outright winner.

Not only is it cheaper than the Cosmo (at full price) but it also comes as a lower cost Wi-Fi only version for $499, which is $100 less than the price for backing the Cosmo on Indiegogo, and $300 less than the Cosmo’s full retail price.

Everything else – Unknown

There are questions we don’t yet have the answers to, but that would otherwise swing a decision for you.  Can the Cosmo be charged from both USB-C ports, as opposed to the Gemini which can only be charged from one side?  Are the USB-C ports on the Cosmo thunderbolt, where the Gemini’s are USB 3.1?  Does the Cosmo take a Nano-SIM, the Gemini uses a Micro-SIM, and can you use a regular HDMI output from the Cosmo, as it’s annoyed some people that the Gemini lacks a specific chip meaning you must purchase the dedicated Planet Computers HDMI adapter cable.

We don’t have answers to any of these questions yet, and so can’t make recommendations of which device is best to purchase.

Delivery – Gemini Wins

When it comes to delivery there’s a very clear winner.  The Cosmo won’t start shipping to backers until at least May 2019, but the Gemini can be purchased today.  If you’re after a mobile computer you can use straight away then the Gemini is it without a doubt.


So there we have it, both the Cosmo and the Gemini have positives, and both have specific use cases where they excel.  In the end it’s a dead-heat with both devices coming out equally.  Which one of them will you choose?  Why not tell us in the comments.

The Cosmo Communicator is still available to back NOW on Indiegogo on this link and by clicking the banner below.  You can help support the Cosmo Communicator with the hastags #CosmoCommunicator and #GoGoCosmo and please help spread the word by sharing this article on the links below.


  1. m0ntala m0ntala

    A very interesting article, which I hope anyone who has any queries will read first!

  2. I think the Cosmo is the best choice for people looking for an all-in-one device, while the Gemini works better as a second device for people who would like to use a PDA as an add-on to their smartphone. Or, for the older folks, with the Cosmo, you can work in Nokia Communicator style, while with the Gemini, it’s rather Psion style.

  3. Kevin Reilly Kevin Reilly

    I would perhaps argue that the Cosmo has a slight edge in PDA and Computing Functionality due to the backlit keyboard, but I guess it could depend on whether you include usability under the umbrella of functionality. The keyboard doesn’t provide any extra features, but it makes it easier to use the ones already there.

    Aside from that, it’s a fair article. A lot of similar “this gen vs. next gen” articles skirt around the issue of price, with an implication that the newer is always the better. In the case of Gemini and Cosmo the price difference really is quite significant even with the Indiegogo discounts, especially if you’ll rarely use the telephony functions, so I was glad to see it given some weight.

  4. Riccardo Riccardo

    I believe that Cosmo in the Planet Computers range was born to “kill” Gemini 4G. It is its perfection.
    Gemini wi-fi represents the idea that the survivors of Psion had a direct heir ten years ago; Cosmo is the current evolution of that idea compared to the standards that meanwhile the smartphones market and the set of applications connected to it have imposed.
    Gemini 4G was in a certain sense the “weak link” of the chain: not essential enough and “pure” (compared to being Psion’s evolution) as its brother, not enough “reckless” to confront the remaining market as it will have to do Cosmos. It was an attempt to run for cover when we realized that for many the “pure” idea of ​​a new PDA would not be enough anymore. . .
    In my opinion the only possible comparison is between Gemini wi-fi and Cosmo, because they still represent two typical users who can be at the extremes.
    The user of Gemini wi-fi can essentially desire a modern PDA, the true successor of Psion 5, to be combined with a telephone as was done with the progenitor; in addition, it will have the possibility of an e-sim in the future and to be able to use it as a secondary device.
    The Cosmo user wants a device that works alone and that brings together in a PDA way the functionalities that it considers expressed too “smart” by the current phones.
    For this reason I believe that Gemini wi-fi will continue to be perfected: because for Planet Computers it represents a very small market segment, but also very solid and still expandable at software level.

  5. m0ntala m0ntala

    Hopefully any software updates, modifications and additions will be applicable to the Gemini as well as the Cosmo, which will obviously benefit users of both devices.

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