^^ Id on't think that these sensors are that much accurate - internal digital thermal sensors embedded in cpu/mobo/hdd are much more accurate - granted external sensors are good but accuracy depends on the placement of these external sensors - for eg. on the screenshot you posted HDD temp i similar but what about cpu temp ?? it's 8c higher in software reading.
I use two HDDs, I haven't attached the even one sensor to CPU.
My HDD sensor is attached to the surface of First HDD(SATA) and CPU sensor is attached to second HDD(PATA).
After making ^^ post I had to open up my cabinet to install another hdd to copy data, so I thought that now I've opened my case why shouldn't I attach the sensors to better places.
So I attached the CPU Sensor to upper surface of heatpipes of Hyper TX3.
HDD sensor is same and attached the SYS Sensor to heatpipe of Sapphire 6850.
Now after different scenario readings my output is this:
HDD Sensor: 98.9 % accurate as temp is same as internal sensor or some time 1C below internal sensor reading.
CPU Sensor: Good Accuracy(remember it's attached to aupper surface) LCD Panel temp is 2C(rarely 3C) lower than internal sensor, when temp reach above 40C, both readings are same.
SYS Sensor(attached to GPU): LCD panle reading is 3c lower than internal sensor reading. But above 38C it is same.
use some temp monitoring app like HWinno/HWMoniotor to get a lot more sensor infos including volts/rpm etc and they have log feature and some of them can show temps on the screen while gaming and some logitech gaming KB supports app like this - you can get the sensor infos on KB display
Means you don't have to open up a program while playing games to check the temp, or while doing some hard end stress test or while encoding on an overclocked processor.
Logs can only be seen after gaming
But after all >
I don't think this is not worth it, but whatever all that matters is individual choice and preference. Thanks for discussion.