MediaTek chipset in Garmins newer lines

[yogazoo]

Speculation

 

With the markets tightening everywhere these days it's not a big suprise that companies try to cut costs wherever they can. Enter chipsets. With the fabled accuracy and stability of the Sirf Star III chipset it's a wonder to me why Garmin has gone to the MediaTek chipset in all of its newer handhelds. But then I heard that the MediaTek chipsets are less expensive.

 

I have scoured the internet to find articles or tech docs describing the differences in the two chip brands but there is precious little available.

 

The reason for my inquiry is because it seems that the Mediatek chips have yet to be proven AND a number of the newer handhelds are experiencing drift and accuracy problems. Could this be a result of the nature of the MediaTek chips? Saving a dollar at the expense of performance?

 

I never remembered so many accuracy/drift problems with the 60CSX/60CX units (Sirf Star III) and was always quite impressed with the performance.

 

Is there anyone out there with the technical knowledge to share regarding this topic? I know it's been covered before in these forums but in light of the drift issues in the newer units such as the Oregon, Colorado and VistaHCX, I feel it's worth revisiting. You can say that the Oregon and Colorado are new and they may eventually get the bugs worked out but the VistaHCX is NOT that new and has been with us long enough one would think.

Edited July 18, 2008 by yogazoo

[gratefulHIKE]

well I own a 60 and a vista hcx among other units. I actually think the vista locks on better than my 60, both running the latest firmwares. The only time I have ever really seen either gps wander to my dislike is when I have been at a stand still for more than 10 minutes, and who really cares then.....constant stable and better accuracy costs big bucks

 

As far as a colorado/oregon drifting that could just be due to the software flaws in interpretation of the signals/time, not really due to the actual GPS at all. Almost like blaming a bad golf swing on the clubs and not the user.

 

Also if the companies dont see a huge performance drop as per dollar savings, I highly doubt they would stake their reputation on that.

 

Here is an older but still relevant article on the workings and how little flaws can create large issues:

http://www.beaglesoft.com/gpstechnology.htm#Timing

 

http://www.markip.com/gps/chip_compare.htm

 

http://www.gpspassion.com/fr/articles.asp?id=175&page=5

[yogazoo]

Really excellent links THANKS! The link to the datasheet is exactly what I was looking for!

[jmedlock]

I don't think the Garmin Oregon has the MTK chipset - well - all we can tell is that it is a different chipset than the Colorado unit.

 

Oregon Chipset

 

This weekend I will see if I encounter the location error problem on the Oregon that I so easily experienced on the Colorado.

 

J

[yogazoo]

I noticed in the Owners Manual of the Colorado that the Velocity error is 0.1 meters/sec whereas the 60CSX says 0.05 meters/sec.

 

It seems, based upon these declarations in the spec sheet page of the manuals that the Sirf Star III chip is more accurate and sensitive to velocity. Anyone know how else to interpret this? What does the Oregon manual say for Velocity?

 

So, my suspicions are kinda, in a way, confirmed that Garmin maybe choosing to save $$ rather than employ state of the art components. Why else would they use a chipset that has a greater velocity error? OR does this even matter?

Edited July 18, 2008 by yogazoo

[jmedlock]

I noticed in the Owners Manual of the Colorado that the Velocity error is 0.1 meters/sec whereas the 60CSX says 0.05 meters/sec.

 

...

 

So, my suspicions are kinda, in a way, confirmed that Garmin maybe choosing to save $$ rather than employ state of the art components. Why else would they use a chipset that has a greater velocity error? OR does this even matter?

 

Garmin also mentions 0.1m/sec for "velocity" for the Oregon.

 

If the Oregon does have the STM Cartesio chipset (seems likely now, but I'm not going to open it up to see), then perhaps Garmin is using "state of the art"; at least that is the same chipset that the new and upcoming DeLorme PN-40 is using. DeLorme is not afraid to mention specifics, unlike Garmin.

 

Speaking of DeLorme: I am going to take a very serious look at the PN-40 to replace 7 GPS units for our search & rescue team. I have used the PN-20 before and found the user interface to be simple to understand, and I suspect the PN-40 would be a great fit for our team. No way am I going to suggest the Garmin Vista H-series since Garmin has (so far) failed to fix the location error drift problem on that unit.

 

J

[yogazoo]

jmedlock, your situation sounds familiar.

 

The department just asked me my recommendations for 10 new GPS units for our field techs. I have a month to decide and I too will give the PN-40 a good look. One thing about the PN-40 is the cheapy buttons (same design/materials as the PN-20) that appearantly wear out relatively quickly. See PN-20 Review/Cons

 

I will also think about the old standby 60CSX. Proven, accurate, bright screen, good design, great battery life, water-tight.

 

Sadly enough, when I think of tough units that are bug-free, durable, intuitive, and full of useful features for navigators/rescuers/hikers none of the newer class comes to mind. Even after the bugs are all worked out, firmware wont fix the ultra-dim screen of the Oregon in sunlight, or the leaky/bad design battery cover on the Colorado.

Edited July 18, 2008 by yogazoo

[jmedlock]

I will also think about the old standby 60CSX. Proven, accurate, bright screen, good design, great battery life, water-tight.

 

Ya, the CSx is also on my short list -- however, I really like the DeLorme Topo USA 7 software and the abilities it provides when interfacing with a DeLorme GPS. It is a tough decision, but if the new Cartesio 32-channel GPS chipset proves to be excellent, then I will probably suggest the PN-40.

 

Regards

[jmedlock]

Duplicate

Edited July 18, 2008 by jmedlock