Acer DX900 Review: Features and Storage Put to the Test

An Acer DX900 review has to start with a clear statement of what this handset was. It was a Windows Mobile phone from 2009, not an Android phone, and it was built around one bold idea: two SIM cards in one pocket device, with fast mobile data on the first line. This Acer DX900 dual SIM Windows Mobile review looks at the phone on its own terms, as a period device, and puts its features and its storage to the test against the expectations of its own year. The Acer DX900 specifications and features explained in detail below come from its verified specification record, so the picture here stays close to what Acer actually shipped.

The full name was Acer Tempo DX900, and the Acer DX900 Tempo DX900 full name and model history is a useful starting point. Acer used the Tempo name for its first serious push into Windows Mobile smartphones, and the DX900 sat at the top of that early range because of its dual-SIM radio. The Acer DX900 release date April 2009 and announcement story began earlier, at Mobile World Congress in February 2009, when Acer showed the phone to the trade press. By the time it reached shops in April, the market was already crowded with single-SIM Windows Mobile devices, yet very few of them could do what this one did. The Acer DX900 price in Europe around 90 EUR placed it as an affordable business handset rather than a luxury flagship, which made its dual-SIM trick even more interesting. An Acer DX900 2009 phone like this was aimed at people who carried a work number and a personal number, or a home SIM and a travel SIM, and who were tired of carrying two handsets.

Readers who want to compare nearby Acer models from the same era can look at Acer X960 After a Week of Use: Review, Storage and Full Specs, a close relative with the same processor and a similar screen, and at Acer F900 Review and Full Specifications: Everything You Should Know, which shows how Acer packaged the same platform in a different body. Those comparisons help, because the DX900 is best understood as part of a family, not as a one-off experiment.

The Dual-SIM Idea That Defined the Acer DX900

The Acer DX900 dual SIM story is the reason the phone is still remembered. It was the first dual-SIM phone in the world to support 3.5G HSDPA on SIM 1 and 2.75G EDGE on SIM 2 at the same time, and that combination was genuinely new in 2009. Most dual-SIM phones of the period forced the second line onto slow 2G only, or made the user switch manually between cards. Here, the first SIM could browse and receive data at HSDPA speed while the second SIM stayed reachable for calls and messages on EDGE. That is the core of any fair Acer DX900 features assessment, and it explains why the phone was marketed to travellers and to small-business owners.

How Dual SIM Worked in Daily Use

In practice, the Acer DX900 3.5G HSDPA dual SIM phone kept both numbers live, so an incoming call on either line could reach the user without swapping cards or restarting the phone. A work call could arrive on SIM 1 while a personal message waited on SIM 2, and the owner could choose which line to use for an outgoing call. The Acer DX900 dual SIM EDGE second SIM data speed was slower than HSDPA, as EDGE always was, yet it was fast enough for email, messaging and light browsing on the second line. For a phone of this period, that was a practical compromise rather than a flaw, because the fast line was always available when it mattered.

Why Two Networks Mattered in 2009

An Acer DX900 business phone features for work and travel package made sense because roaming charges were high and many people kept a local prepaid SIM beside their main contract SIM. The DX900 let a traveller land in a new country, put a local SIM in the second slot, and keep the home number live for urgent calls. The Acer DX900 vs other Windows Mobile phones 2009 comparison turns on this point: rivals often had a better camera or a larger screen, but they asked the owner to choose one number. This phone refused that trade-off, and that refusal was two numbers, one handset in its simplest form.

Design and Build

The Acer DX900 design is compact, plain and businesslike. At 106 x 60.5 x 17 mm and 147 g, it fits the hand without feeling fragile, and the Acer DX900 dimensions weight and pocket friendly design made it easy to carry beside keys and a wallet. The Acer DX900 dimensions are worth stating plainly because the phone is thicker than a modern slab, yet its small footprint keeps it pocketable. An Acer DX900 pocket phone in the true sense, it slips into a jacket pocket and stays there without pulling the fabric down. The front is dominated by the screen, with a navigation pad and call keys below it, while the back carries the camera lens and a removable battery cover.

Size, Feel and Controls

The body uses dark plastic with a sober finish, and the keys have enough travel to be pressed without looking at them. The Acer DX900 classic look has aged well precisely because Acer did not chase fashion: there are no bright colours and no fragile gloss panels to scratch. A hardware keyboard is absent, so text entry depends on the screen, which is covered in the next section. The phone feels dense rather than hollow, and the battery cover sits flush, which matters for a device that was meant to be carried every day.

In the Hand

Held in one hand, the DX900 is easy to reach across with a thumb, and the call and end keys fall under the thumb without stretching. The weight of 147 g gives it a steady feel, and the 17 mm thickness provides a grip that a thinner phone would not. For long calls, that grip is a real comfort.

In a Pocket or Bag

The small 2.8-inch screen keeps the overall length short, so the phone does not dig into a hip when sitting down. It is the kind of device that could be carried in a shirt pocket, which is rare for a smartphone with a full Windows Mobile system inside. That portability was part of its appeal to people who already carried a laptop bag and did not want a second bulky device.

Display and Stylus Input

The Acer DX900 display is a 2.8-inch TFT resistive touchscreen with VGA resolution of 480 x 640 pixels. The Acer DX900 resistive touchscreen display and VGA resolution gave it a sharper picture than many rivals, because VGA on a small screen produces dense, readable text. The Acer DX900 2.8 inch TFT display size and clarity suited email, calendars and maps, and the 4:3 aspect ratio matched the Windows Mobile interface of the time. Colours are restrained rather than vivid, and the screen is best viewed straight on, as resistive TFT panels of this era usually were.

Screen Clarity and Everyday Reading

For reading messages and documents, the high pixel density helps. Small fonts stay legible, and the Start menu, contacts list and inbox all fit a useful amount of information on screen. Outdoor visibility is modest, as with most phones of 2009, and the screen needs a shade or a higher brightness setting in strong sunlight. Indoors, it is clear and steady, and the VGA panel is one of the stronger parts of the Acer DX900 specs.

Stylus Input and Accuracy

The Acer DX900 stylus input and resistive screen accuracy is a period feature that modern readers should not judge by capacitive standards. A resistive screen responds to pressure, so a stylus, a fingernail or a gloved finger can tap it, and the bundled stylus makes precise taps on small menu items easy. The Acer DX900 stylus lives in a silo in the body, so it is always at hand for handwriting recognition, for tapping checkboxes, and for drawing a quick note. Handwriting input and on-screen keyboards both work, and the stylus is the more accurate of the two for the small controls in Windows Mobile. The Acer DX900 software rewards that precision, because its menus were designed for a pen rather than a fingertip.

Performance and Windows Mobile Software

The Acer DX900 performance comes from a Samsung S3C 6410 processor running at 533 MHz, with 128 MB of RAM and 256 MB of ROM. The Acer DX900 Samsung processor performance and 128MB RAM combination was standard for a good Windows Mobile phone in 2009, and it handles the operating system, email and maps without long waits when the phone is kept tidy. The Acer DX900 Windows Mobile system is Windows Mobile 6.1 Professional, a business-oriented platform with Office Mobile, Outlook email, Internet Explorer Mobile and a full contacts and calendar system. An Acer DX900 Windows Mobile 6.1 Professional software review has to note both sides: the system is powerful and flexible, with real multitasking and real file management, yet its menus are dense and it expects the user to learn them.

Processor, RAM and ROM

The Acer DX900 256MB ROM internal memory and limitations deserve a plain explanation. The 256 MB of ROM holds the operating system and the built-in applications, so the free space left for the user is much smaller than the headline figure. The 128 MB of RAM holds running programs, and opening too many at once will slow the phone down. That was normal in 2009, and it is why the microSD slot matters so much on this handset. For everyday use, one or two applications at a time run smoothly, and the processor is fast enough for email, messaging, maps and music.

Windows Mobile Apps and Daily Tasks

The Acer DX900 contacts messages and calendar Windows Mobile apps are the heart of the phone for a business user. Contacts sync with Outlook, messages thread by conversation, and the calendar supports appointments, reminders and recurring events. Office Mobile opens Word, Excel and PowerPoint files, which made the DX900 a useful companion for people who reviewed documents away from a desk. The Acer DX900 mobile internet browsing on HSDPA network experience is decent for its year: pages load at HSDPA speed on SIM 1, and the VGA screen shows more of a page than a QVGA screen would. The browser is old by later standards, yet for news, email and search in 2009 it did the job.

Camera and GPS

The Acer DX900 camera is a 3.2-megapixel rear camera with autofocus and an LED flash, plus a front VGA camera for video calls. The Acer DX900 camera quality with autofocus and LED flash is best described as useful rather than outstanding: in daylight it records clear, well-exposed snapshots for messages and records, and the autofocus helps with close subjects such as documents and business cards. The Acer DX900 3.2 megapixel rear camera sample quality in good light is sharp enough for a small print or a screen, while low-light shots show the limits of a small sensor and a single LED. The Acer DX900 autofocus system locks onto a subject with a half-press style focus step, and the LED flash adds light for nearby subjects in a dark room.

Rear Camera in Practice

For a 2009 phone, 3.2 megapixels was a respectable figure, and the camera interface offers the usual white balance, brightness and scene options. Photos are saved to internal memory or to the card, and the phone can send them by message or email without a computer. Video recording is modest, as expected for the period, and it suits short clips rather than long films. The camera is a working tool on this phone, not a headline feature, and it should be judged that way.

Front Camera, Video Calls and GPS

The Acer DX900 front VGA camera for video calls review is short: the front camera exists for video calling over 3G, and it does that job. The Acer DX900 video call picture is small and soft, yet it is enough for a face-to-face call, which was still a novelty for many buyers in 2009. The Acer DX900 WiFi Bluetooth connectivity and video calling package also includes Wi-Fi 802.11 b/g and Bluetooth 2.0 with EDR, so the phone can join a home or office wireless network and pair with a headset or a car kit. The Acer DX900 GPS navigation with SiRFstar III receiver is a stronger point: the SiRFstar III chip was a respected GPS receiver, and with mapping software it gives turn-by-turn guidance and a reliable position fix outdoors. The Acer DX900 GPS works without a mobile signal once maps are loaded, which made it useful for driving in areas with weak coverage. Readers comparing Acer phones of this year may also want Is the Acer M900 Worth It? Review, Specs and Verdict for a single-SIM alternative with a keyboard, and Acer DX650 Review and Specifications: Form Factor, Everyday Performance and the Verdict for a smaller dual-SIM sibling in the same Tempo family.

Full Specifications

The table below gathers the Acer DX900 specs in one place. It is the reference for the rest of this article, and every figure in it matches the verified record for the phone.

The Acer DX900 specs in that table explain the phone in a single glance: a compact Windows Mobile device with a sharp VGA screen, a capable GPS receiver, and a dual-SIM radio that no rival matched at the time. The Acer DX900 release in April 2009 put those parts together at a price that a working buyer could justify, and the Acer DX900 price of about 90 EUR remains the figure to quote when the phone is discussed today.

Storage and Memory in Practice

The Acer DX900 storage story is the part of the title that needs the most careful testing, because the headline memory figures tell only half the story. The Acer DX900 microSD card storage expansion guide in this section explains how the phone was actually used: internal memory for the system and a card for everything else. The phone has 256 MB of ROM, and after the operating system and built-in programs, the free internal space is limited. Photos, music, maps and documents therefore belong on a microSD card, and the phone is designed around that habit.

Internal Memory and Its Limits

The Acer DX900 256MB ROM internal memory and limitations mean that a user who tried to keep a music library or a large photo collection in internal memory would run out of room quickly. That is not a defect unique to this phone; it was true of almost every Windows Mobile phone of 2009. The practical answer was to treat internal memory as working space and the card as the library. Email attachments, downloaded files and camera photos can all be pointed at the card, and the file manager makes it easy to move files between the two locations.

What Fits Inside

Inside the phone, the working set is contacts, messages, calendar entries, a few installed programs and the current camera roll. Those items are small, and they fit comfortably. Large items such as maps for GPS navigation, a music collection and a photo archive do not belong there, and the phone performs better when they are kept on the card.

microSD Expansion

The Acer DX900 microSD slot location and supported capacity is a practical detail that owners needed to know. The slot sits under the battery cover or beside the battery compartment on this design, so the card is protected once the cover is on, and it can be swapped when the phone is off or the cover is removed. The Acer DX900 microSD card itself can hold music, photos, videos, documents and offline maps, and a card of several gigabytes transforms the phone from a tight business tool into a capable media companion. The Acer DX900 storage test, in plain terms, is this: with a card fitted, the phone has room for a working library; without a card, it is a phone for calls, messages and light documents only. That distinction is the honest result of putting the storage to the test, and it is why the card slot is one of the most important features on the handset.

Using the Card Well

A good routine is to set the camera to save to the card, to keep music in a single folder on the card, and to keep a copy of contacts on the card as a backup. The phone reads the card quickly, and the file manager shows both internal memory and the card side by side, so moving a file is a simple tap-and-hold action. For a collector today, a card also makes it easy to load period maps and period music without touching the fragile internal memory.

Battery Life, Connectivity and Daily Use

The Acer DX900 battery is a removable Li-Po unit rated at 1530 mAh. The Acer DX900 battery life and removable battery review finds a familiar 2009 pattern: a day of normal use with calls, messages and some browsing, with heavier GPS or Wi-Fi use shortening that day. The Acer DX900 1530 mAh battery capacity and charging time is modest by later standards, yet the removable design is a real advantage, because a spare battery can be carried in a bag and swapped in seconds. That was a normal habit in 2009, and it made the phone practical for long travel days.

Battery and Charging

Charging is by cable, and a full charge from empty takes a few hours, as with most phones of the period. The battery cover comes off without tools, so a worn battery can be replaced rather than sending the whole phone away. For a phone that is now a classic, that replaceable battery is also a collector advantage, because a fresh cell can bring a stored handset back to life.

Connectivity in One Place

The Acer DX900 connectivity list covers HSDPA on SIM 1, EDGE on SIM 2, Wi-Fi 802.11 b/g, Bluetooth 2.0 with EDR, GPS and a microSD slot. The Acer DX900 HSDPA connection gives fast data on the main line, the Acer DX900 WiFi connection gives free data at home or in the office, and the Acer DX900 Bluetooth link pairs with headsets, car kits and other phones for file transfer. The Acer DX900 connectivity as a whole is broad for 2009, and it is the reason the phone could serve as a work tool, a travel tool and a media player in one pocket. The Acer DX900 Tempo name also appears on the box and in the manual, and the Acer DX900 Tempo identity is a useful check when buying a second-hand unit, because the Tempo branding confirms the model family.

Pros and Cons

No honest Acer DX900 review can end with praise alone. The phone did something new, and it did it well, yet it also carried the limits of its platform and its year. The balance below is the verdict of the tests in this article, and it is written for a reader who wants to know whether the phone was good in 2009 and whether it is worth seeking out now.

What We Liked

First, the dual-SIM radio with HSDPA on one line and EDGE on the other was a genuine first, and it solved a real problem for people with two numbers. Second, the VGA screen was sharp for its size, and the stylus made the dense Windows Mobile interface usable. Third, the GPS receiver was strong, the camera was capable in daylight, and the removable battery made long days practical. Fourth, the compact body and the low price made the phone easy to justify as a work handset. The Acer DX900 features as a set were coherent: every part served the same travelling business user, and built for travellers who carried two lines is a fair summary of the design.

What Held It Back

First, the 128 MB of RAM and the small free internal memory meant that the phone needed a microSD card to feel roomy, and heavy multitasking could slow it down. Second, the resistive screen needed a stylus for precise work, and finger taps on small controls could miss. Third, Windows Mobile 6.1 was powerful but dated in its menus, and it lacked the smooth touch interface that later platforms brought. Fourth, the camera and the battery were adequate rather than outstanding, and the phone was never a media flagship. Those limits do not erase the dual-SIM achievement, yet they explain why the DX900 is remembered as a clever specialist rather than as a mass-market hit.

Verdict and Frequently Asked Questions

The verdict is straightforward. In 2009, the DX900 was the right phone for a narrow group: a business user or a frequent traveller who needed two numbers live, fast data on one line, GPS, and a proper email and calendar system in a pocketable body. For that user, it was excellent value at about 90 EUR. For a buyer who wanted a single-SIM media phone with a large screen and a simple interface, other phones were a better fit. Today, the phone is a collector item and a piece of mobile history, and that is where its value now lies. The Acer DX900 classic phone collector value in 2026 rests on its first-dual-SIM claim, its condition, its box and accessories, and whether its battery still holds a charge. The Acer DX900 second hand price and buying tips today are simple: check both SIM slots, check the screen for dead pixels and stylus marks, check the camera and the GPS fix, and ask for the charger and the stylus. The Acer DX900 accessories charger headset and carry case options were modest at launch, yet a complete set with the original charger, headset and case is worth more to a collector than a bare handset.

For a final comparison with the smallest Acer in the same family, see Our Acer beTouch E101 Review: Value for Money, Performance and Detailed Specs, which shows how Acer later simplified the formula for a lower price. The DX900 remains the more capable and more interesting of the two, because its dual-SIM radio and its GPS receiver were aimed at a working user rather than a first-time buyer. The phone is a pocket companion from another era, and it deserves to be remembered for the problem it solved rather than for the features it lacked.

Verdict in Short

If the test in the title is whether the features and the storage hold up, the answer is mixed in the best sense: the features hold up as a period solution, and the storage holds up only with a microSD card fitted. That is an honest result, and it is the result a careful reader should take away from this review.

Was the Acer DX900 an Android phone?

No. It was a Windows Mobile 6.1 Professional phone from 2009, and it never ran Android. Its interface, its applications and its file system all belong to Windows Mobile, which is why the stylus and the Start menu matter so much to its story.

When was the Acer DX900 released?

It was announced in February 2009 and released in April 2009. That April 2009 release date puts it in the last strong year for Windows Mobile before later platforms took over the smartphone market.

What made its dual SIM special?

It was the first dual-SIM phone in the world to support 3.5G HSDPA on SIM 1 and 2.75G EDGE on SIM 2. That meant fast data on the main line while the second line stayed live for calls and messages, without swapping cards.

How much storage does the Acer DX900 have?

It has 256 MB of ROM and 128 MB of RAM, with a microSD slot for expansion. Internal memory alone is tight, so a microSD card is the practical answer for photos, music, maps and documents.

Is the Acer DX900 worth buying today?

As a daily phone, no, because its networks, browser and applications belong to 2009. As a classic for a collector, it can be worth seeking out if the condition is good, both SIM slots work, and the price is low, because its dual-SIM first remains a genuine piece of mobile history.