Tuesday, August 31, 2010

Enso ZenPad 4 Tablet Review

Enso sells a 10.2” Android tablet called the ZenPad 4 (ZenPad) which is also known by many other branded names such as the WiiPad, ePad, FlatPad, & Orphan M16.  All which are based on ZeniThink ZT-180.  Our initial intent was to buy the FlatPad from Flat Computing but backed out after some mix up with the processor (see Conclusion for details).  We heard about Enso and decided to try out the ZenPad 4.  We were curious how a $200 10” Android 2.1 tablet would perform.

The only comparison that I will make on the ZenPad against Apple's iPad is on the exterior since they are similar.  The ZenPad is slightly larger (10.63” vs. 9.56”) and weighs almost the same (1.7lbs vs. 1.5lbs) as the iPad.  While the iPad has a 9.7” capacitive screen, the ZenPad has a 10.2” resistive screen.  Bigger but not better.  The ZenPad is made up entirely of plastic.  Although the back is made to look as it is made of metal, it is not.  The screen is made of highly glossy and reflective plastic not glass.  That is all that I will say about the iPad since one cannot fairly compare the $499 iPad against the $199 ZenPad.  The ZenPad does include USB port, micro-USB (OTG) port, headphone jack, micro-SD slot, and Ethernet port (which it comes with an adapter).  The included power adapter/charger is shorter (47”) than most cell phone chargers.  The external speakers are, to our surprise, pretty decent.  We played music and watched videos on a very high volume with minimal to little distortion.  Overall, the exterior quality is what you would expect from a $200 tablet. 
     There are a few buttons on tablet.  There is a main button on the front which is mostly used to go “back.”  The “home” button is actually on the Android UI.  There is a power button and an Up & Down button which we assumed was a volume control.  However, it does not control the volume.  The “right” button (furtherest from the power button) brings up a task manager which displays all opened apps.  This allows you to switch open apps.  The “left” button brings up the menu option for the app you have opened. 
     Included with the tablet is a charger, instruction manual and Ethernet cable adapter (which does work).

Under the hood, the ZenPad runs on an ARM11 (v6) 1.0GHz processor.  (Most current Android phones are using a higher-end Cortex A8 ARM chip or similar processor. Only Cortex A8 & higher are Flash capable.)  It has 256MB of RAM which is better than the lower end tablets (with 128MB) but still below the preferable minimum of 512MB.  A micro-SD is definitely required not only for storage but also many apps need it to operate correctly.  The ZenPad does have a built-in accelerometer (auto-rotates the screen) which works OK.  Actually, it worked very well during our video review.  However, it does not work well with games that require the accelerometer.  As many have reported, we also experienced the unit getting warm on the lower right hand side (see picture below).

     The Wi-Fi (802.11a/b/g ) has actually performed well.  We did not experience any major issues with it.  The first time we connected to our secured wireless network, the ZenPad connected with no issues.  In addition, we tested the Wi-Fi connection at a public Wi-Fi network and experienced no problems connecting or accessing the Internet.  In the one hour of testing, the Wi-Fi connection did drop once.  We have read of individuals having problems with their Wi-Fi connection but we have not experienced any issues.  We tested the connection at 2 different distances: 1) approximately 56 feet between the router (located indoors) and the tablet with a wall (standard house wall separating inside & out) in between; and 2) distance of approximately 36 feet between the router (located on the first floor) and the tablet (tested in second floor).  As you can see by the chart below, the signal strength drops almost 50% from 10 feet to either the 70 foot or 45 foot (separated by a floor) distance.  Connection was still decent but experienced almost a third decrease in download speed. 

    We were able to connect a USB keyboard and it worked without any problems.  USB Flash drives also worked fine. 

As mentioned before, the screen is a large 10.2” with a resolution of 1024x600.  The screen is resistive, not capacitive, so it is not very responsive although the responsiveness was higher than what we were expecting.  In addition, it is not multi-touch so forget about pinch zooming.  When typing on the standard keyboard, it responds well although if you type too fast an incorrect key may register.  Scrolling is the biggest complaint.  As you scroll up and down, most of the times you will activate the wrong item.  The screen is also difficult to see in bright daylight due to the very glossy screen.  Turning up the brightness to high helps a little.  Nonetheless, the screen is ZenPad's major weakness.

As our video demonstrates, the Zenpad works well with all multimedia (pictures, music & videos) types.  We tested these 3 types using the included RealPlayer which we found easier to use than the included Gallery app.  There are other better apps to use but our focus is only on the apps included.  For the pictures, the quality of the images was good.  The colors were not as bright or lively as the original file.  If you are looking for the ideal resolution to take up as much of the screen as possible, 1280x800 works well.  For music, RealPlayer worked great.  We were able to listen to music while surfing the Internet and playing games.  As mentioned before, the external speakers were surprisingly good.  At high volume, distortion was minimal.  For videos, we tested using MP4 format with 1250 & 1500 bit videos.  Both played very well with no stuttering.  There were some artifacts especially in dark scenes in both videos but it was minimal.  The ZenPad had no trouble processing the 1500 bit video.  We used an animated movie to show the “fullness” of the video (colors, brightness, contrast, etc.).  We also tested using a live action film as shown in our video.  One thing that we encountered with RealPlayer is that if you are watching a movie and switch to **Settings, the movie will not play once you switch back.  We did not test HD videos as the screen resolution does not support HD quality.  Overall, the multimedia was acceptable.

Applications (Apps)
The ZenPad did not include certain apps that one would expect such as Android Market, Gmail, YouTube, FaceBook, etc.  Of course, you can add these (except for maybe the Market) on your own.  Non-standard Apps that were included are: RealPlayer; TaskKiller; SlideMe (app store); SkyFire; and Benchmark.  These apps worked well.  Navigating through the Internet on both the standard browser and SkyFire worked fine.  Our preference is SkyFire although there are other good browsers available.  It’s a matter of preference.  Also included was Navigation although the unit does not have GPS built-in.  We did install the YouTube and Facebook app.  Both worked well.  However, we tested the YouTube app version 1.3 which worked fine.  When we updated to version 1.6.2, it did not work so we reinstalled the old version.  The included Email app also worked fine but it is very basic and does not alert you of new emails.  Again, one can find better alternatives.  We used the tablet as an eReader using both the included iReader and Adiko app.  Both apps worked well in both day & night mode.  We did test reading a PDF file and found Repligo to work better than DroidReader or Office Professional.  Repligo was slightly faster but more importantly render the complex PDF file (with multiple images, fonts & formats) correctly.  However as mentioned before, the highly glossy screen is difficult to see in bright daylight even with brightness turned high.

At this time, we have not chosen a tablet to use as a benchmark for others to be compared against.  In the future, we will pick a particular tablet whose performance is very good and use it as baseline.  For the moment, we will be benchmarking tablets against three different and powerful Android smartphones (HTC Evo; Droid Incredible; and Droid X).  Our belief is that a tablet should be more powerful than (or at minimum be as powerful as) a smartphone.  Tablets should really exceed the best smartphones currently on the market.  Below are the benchmarking scores of the ZenPad versus the Android phones:

Based on this, one can clearly see that the GPU is not as powerful as the phones based on the Neocore benchmark.  This is no surprise.  However, one will see that the ZenPad's GPU score is higher in Softweg's Benchmark app.   Softweg measures graphic performance in 2D while Neocore is an OpenGL-ES 1.1 graphics performance benchmark that shows off some of the techniques that are possible on accelerated platforms such as 1-pass light maps and bump mapping.  This is a demo that is based on Qualcomm's Adreno GPU architecture so its more stringent test for the GPU.  We consider Neocore's score to be a more reliable indicator.  As for the CPU, the scores are for informational purposes.  Based on the Linpack and Softweg's CPU score, one would think the ZenPad has a better CPU but it does not.  Unfortunately, it is possible to “trick” the benchmark in producing these scores.  The ZenPad could have an Android OS with a JIT Dalvik engine.  ARM11 processors cannot produce Linpack scores in the 9-10 range.  Scores of 7-8 on a Cortex A8 is realistic.  Consider the BenchmarkPi score as a very rough indicator of performance.  Cortex A8 are on average 20-30% faster and more efficient than ARM11.
   (Different benchmarking apps may test  different aspects of the CPU and GPU which would account for variance.  One cannot look simply at one set of benchmark scores.  One should view all in an aggregate.)

Battery Life
In order to standardize testing, we conducted two battery tests:  1) played a movie that repeated until the unit shut off (with Wi-Fi turned on); and 2) played a movie that repeated until the unit shut off (with Wi-Fi turned off).  Both tests had the brightness at 50%.  For the first test, the battery lasted an average of 3:50 hours while the battery lasted an average of 4:50 hours on the second test.  We are aware that most individuals will not have the Wi-Fi turned on while watching a movie.  However, this testing method is designed to see how long the battery life is under the most intensive processes.  You can rest assure that using the Internet will last significantly longer than the results posted here.  One item of concern is that we were never able to get the battery to fully charged.  No matter how long we charged the battery, the maximum that it charged was 90%.  This occurred after completely discharging and recharging the battery several times.

Overall, we were fairly pleased with what we saw.  Our expectations were low but the ZenPad 4 met or exceeded most of them.  The resistive screen is its major weakness along with the processor.  Having more RAM (at least 512MB) and also built-in memory would improve the product.  Initially, the tablet was being marketed with a Cortex A8 processor which would have been ideal.  However, it appears that the manufacturer, whether intentional or not, marketed it as having the Cortex processor when in fact it did not.  Enso, along with a few other resellers, were forced to acknowledge the mistake and update the specs to the correct but less powerful processor.  We did not encounter the same problems that most other buyers encountered.  This tells us that quality control is poor.  There is no excuse for this.  All tablets should perform the same as long as the same ROM version is installed.  However, this is the risk one takes when buying from certain vendors overseas.  We also experienced the ZenPad freezing up on us on a few occasions.  As for the positives, the Wi-Fi worked fine, videos played without any hiccups, external speakers sounded very good and Internet browsing was very good.  If you can overcome the weaknesses and $200 (plus shipping) is your budget, the ZenPad 4 is acceptable as long as you have the latest ROM version (and hopefully receive a working unit).  If you are looking for higher quality materials, a more powerful processor and a sharp multi-touch capacitive screen, you need to look elsewhere and also be willing to spend a lot more.  We rather spend the extra money for the better quality tablet.


  1. The reviewer is right to stress the importance of using the most up to date ROM. Which is why the review falls somewhat short. It does not specify what ROM they reviewed.

    They reviewed either an early ROM or a defective model as opening apps acidentally while scrolling is not a widely reported problem with the much more common unbranded zenithink tablet.

    Agree with the reviewers take on the cortex processor controversy, wifi range, gaming g-sensor deficiency (my biggest disappointment) and need for more memory. But call me a skeptic about the need for speed / cortex processor. All of the apps I need in a large tablet (games excluded) fly on the zt-180. Opera-mini feels subjectively just as fast as on my nexus one. The zt-180 has more than enough horsepower to turn pages quickly Am I going to read books faster with a cortex processor?

    Kidding aside, until someone shows a meaningful difference in performance between processors with actual applications that I use my expectations as to speed will remain exceeded by the zenithink tablet. Screen brightness, responsiveness and fit and finish all exceed expectations as well.

    And everyone seems to have forgotten that resistive screens can be more accurate than capacitive screens, which makes it easier to correct dismal spelling like mine. In a bigger device multitouch less important and accuracy more important. I still prefer capacitive but not at a 2x price premium (whereas with phones I would gladly pay double). Thank-you for a better review than engadget.

  2. In the part 2 video (5:06) says they are using rom 0804 (aka 0803)

  3. Thank you for your comments. I have updated the ROM version in the Update Posting. We apologize for excluding the ROM information as it is a key in a tablet's performance.

  4. Newest ROM is 0827: http://www.zenithink.com/product_view.asp?id=240