GPS ChipSet Comparison - MTK II, SkyTra Venus 6, 65nm SiRF III, MTK I, 90nm SiRF III

GPS ChipSet Comparison Table

ChipSet Name	MTK II	SkyTra Venus 6	65 nm SiRF III	MTK I	90 nm SiRF III
Number of Channels	66	65	20	32 or 51	20
Sensitivity Rating (Negative lower is better)	-165dBm	-161dBm	-159dBm	-158dBm	-159dBm
Power consumption (lower is better)	very low	very low	very low	low	high
TTFF (Time_To_First_Fix)	very fast	very fast	fast	fast	slow
Editor's Ranking	*** * * * ***	*** * * * ***	*** * * * ***	* *	*
Loggers / Receivers using this GPS Chipset.	Qstarz BT-Q1000X T Qstarz BT-Q1000XTM Qstarz BT-Q1000 e X Qstarz BT-Q1300ST Holux M-1000C Qstarz BT-Q818XT Qstarz LT-Q6000 Columbus V-900 Columbus V-990	Canmore 750F(L) Canmore 750F Canmore 730FL-S Canmore 730F Canmore GP-101 Canmore GP-102	i-gotU GT-120 i-gotU GT-600 i-gotU GT-800 i-gotU GT-800 Pro

Why more GPS channels, better accuracy.

General speaking, we need 1 channel per GPS satellite. There are only 30 satellites in the system & why we need so many channels
in the GPS receiver/logger?

According to GPS algorithm, bigger number of satellites a GPS tracks at a time, better accuracy the GPS can calculate.

In a period of time, some GPS satellites disappear from horizon & GPS receiver lost connection from them. Meanwhile, some other
GPS satellites appear. If the GPS is not able to “capture” those newly available satellites fast enough, the number of satellites track
by the GPS is reduced. Hence the accuracy will be reduced.

The speed of “capture” those newly available satellites are very important. In order to speed this up, GPS receiver must reserve a big
number of channels for searching new satellites all the time. You know, searching new GPS satellites is time consuming. That is the
reason so many GPS channels is needed. Till this moment, MTK II chipset has 66 channels, the most GPS channels in the market.

Buyers' Guide - Which GPS (chipset) shall I choose? "MTK II", "SkyTra Venus 6 "or "65 nm SiRF
III"?

MTK II chipset GPS has the best overall performance.
SkyTra Venus 6 chipset GPS has very good performance & affordable.
65nm SiRF III chipset GPS is best for low speed tracking/navigation. (For example, Geocaching)