Differences in chinese sat navs

Discussion in 'GPS Navigation' started by irnbru, Oct 9, 2015.

  1. irnbru

    irnbru Funster Life Member

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    20151009_172226.jpg While we were on holiday our 2 MHs each had a Chinese sat nav. One MH had a Novatec and the other a Mediatek both I thought I had updated the maps on before we left but on holiday each sat nav wanted to take us different routes despite the profile vehicle lengths etc all being set to the exact same. Now that I'm home I have copied the same set of UK and France maps to both sat navs, and included same set of speeds, dimensions, break times etc so why is there such a big time difference?. I have posted an example.
     
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  2. GJH

    GJH Funster Life Member

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    Different versions of the iGo Primo software perhaps?
     
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  3. irnbru

    irnbru Funster Life Member

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    I was thinking that too Graham but 2 hrs over a distance is quite significant. At first I thought one was registering break times and the other wasn't but when I analyse the roads the differences just grow in minutes from road to road.
     
  4. andy63

    andy63 Funster

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    Hi Sandra don't know why the times vary so much but if I'm getting it right then the milage for the various routes are very similar and both routes look very similar on the screen shot. .
    To me the times are a bit academic ..
    My gamin and Chinese unit frequently choose different routes both have same vehicle dimensions and usually have to say I think the Chinese unit chooses best...
     
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  5. irnbru

    irnbru Funster Life Member

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    We had a NIGHTMARE with these sat navs to put it mildly in France so much so Alan gave up and used his tomtom which I have to add still didn't have us going the same way and led to even greater problems...Truck route v car route.
     
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  6. andy63

    andy63 Funster

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    Well I've fallen into the trap of just going with the sat nav after sometimes checking it's chosen route with a map...
    If I don't agree I just enter another location that takes me on the route I would prefer. .
    Felt like I couldn't have done without it in Spain and Portugal. ..
    In your situation with Alan leading you must surely just have to follow regardless of what your nav tells you... yours should then re route...
    Hey your home so can't be that bad lol...
    Ta Andy
     
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  7. John Laidler

    John Laidler Funster

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    If they are from different manufactures then it would be extremely surprising if they chose the same route!
     
    Last edited: Oct 9, 2015
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  8. TheBig1

    TheBig1 Funster Life Member

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    one has the speed limits set for hgv's the other not?
     
  9. lunarman

    lunarman Funster

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    Hi @irnbru

    To prove whether the difference is hardware related, I would copy the complete primo folder form one unit to an sd card, then use this in the other unit. Don't forget to change the navi path of the unit to work off the sd card. You will then know that everything is the same on both units.
    If the 2 units then give different results then it must be something to do with the hardware. If they give the same then there is something diffent in the software and/or maps and settings.

    I have had one of these units now for a couple years and have been on 2 trips a year to france and it has performed flawlessly. This year we have spent 9 weeks and covered 4500 miles without problem.

    When you say you had a nightmare what specifically has been the problem?

    lunarman
     
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  10. irnbru

    irnbru Funster Life Member

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    Both the exact same.
     
  11. irnbru

    irnbru Funster Life Member

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    @lunarman The units kept freezing and wouldnt turn off at times to even reboot it and sometimes came up with low memory. Alan couldn't see his either due to sunglare so ended up using his car tomtom which took us on a road that wasn't suitable for MHs that came to a dead end with car park and height barrier. We caused traffic mayhem for half an hour. Can laugh at it now though.
     
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  12. GJH

    GJH Funster Life Member

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    Why? Basic principle - same software, same data, same result.

    The hardware shouldn't make a difference of the type under discussion. There has to be some difference in the software or the data to produce different results.
     
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  13. andy63

    andy63 Funster

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    Graham surely the results arnt that different in Sandras original screen shot of the sat navs chosen route.. The milage are the same near enough it's only the estimated times for the journey that are significantly different..
    Andy.
     
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  14. Bartyfixedit

    Bartyfixedit Funster

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    The algorithms that are doing the calculation are very complex. It may well be that the order that the various calculations are carried out in is varied as you change the settings.

    I use copilot on my phone. One of the options is whether or not to use active routes. If you calculate a route with active routes turned off, then turn active routes on and allow it to recalculate, and then turn active routes back off again and recalculate, the time of arrival will be different for the 2 active routes off scenarios.

    When you think how many variables the system is having to consider, and the number of various settings we can play around with, it's no great surprise that variations can creep in.

    I use both tom-tom and copilot and prefer the copilot.
     
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  15. JockandRita

    JockandRita Funster Life Member

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    Hi Sandra,

    Glad to see that you are back home safely. I hope you and Mum had a great time on your first European trip.(y)

    The only thing that I can think of, is if one of the Sat Navs has the "historical traffic" option chosen,as that would give different timings dependant on the time of day travelling, ie, if I route plan at 20.00hrs the night before the journey, and then turn the unit back on at 08.30 the next day, the journey times can be different, taking into account peak commuter traffic times.
    I unchecked the historic traffic option on ours.

    I too have been using this unit for around two years now, and where I have suspected it of getting it wrong, and making my own decision, on each occasion, the unit has been right, proving me wrong.
    I certainly couldn't say the same for the TT720 European Truck Maps.
    On one occasion in particular, when I took a known detour to avoid traffic queues, it tried to direct me through a farmer's gateway with a 44 tonne truck, to access the A1 again near Pontefract. :(

    Good luck with resolving the issue. (y)

    Cheers,

    Jock. :)
     
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  16. TheBig1

    TheBig1 Funster Life Member

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    if the distances are pretty much identical, the difference in projected times can only be down to vehicle speed. that is why I asked about the profile and whether one was set to hgv, the other car. as already mentioned, the historical data the satnav can optionally use also affects the times

    the hardware is near identical as is the operating system so the difference can only be data related
     
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  17. GJH

    GJH Funster Life Member

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    As Jock & The Big1 have said, if the software is the same there must be differences in the data in some way(s). As I've posted on previous threads, the iGo software does sometimes over-ride input parameters with system standards. For instance, avoiding a road with a 7.5 tonne limit even though the vehicle weight input is 3.5 tonnes - i.e. it assumes that any vehicle with a Lorry profile will be over the limit.
    If Nozatec and Mediatek have set up their software images in slightly different ways then that would account for it.

    This thread reminds me that I must contact Garmin. With my first Garmin (car) sat nav (Nuvi 1300) a few years ago I noticed that it underestimated journey times and have experienced the same with the Garmin Camper 760 and Nuvi 2569 which I have now. We used both the 760 and the Nozatec on our recent trip to and from Lincoln Showground. The Garmin underestimated the journey time and the Nozatec slightly overestimated it (though it was closer). As we neared the end of the journey both adjusted their arrival times.
     
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  18. Badknee

    Badknee Funster

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    [QUOTE="irnbru, post: 1580663, member: 26684"so why is there such a big time difference?. [/QUOTE]
    Different time zones in China?

    I'll get my coat
    :getmecoat:
     
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  19. Gellyneck

    Gellyneck Funster Life Member

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    Don't know why you're all rabbiting on about hardware \ software being the problem!
    You need to think about the obvious, and almost certain, rationale behind this.

    Two motorhomes with two comparable sat navs so must be down to operator differences. Alan = male and Sandra = female! Nuff said.:whistle2::clap2::imoutahere:
     
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  20. mjltigger

    mjltigger Funster

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    The software I work with does route scheduling. We can be working with many thousands of trips at a time. Running the same trips through the algorythm repeatedly can give different results but only if something has changed causing database sorting to produce differing results.

    The same trip run through the same algorythm must always produce the Dr result.

    Something is different between the two units and I would lay my money on a seemingly innocuous configuration setting.
     
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