Northbridge temps for Gigabyte 990FXA-UD3

Recently had to upgrade my mobo, since my last board (MA785G-UD3H) kicked the bucket a week and a half ago. Decided on a Gigabyte 990FXA-UD3, since I didn't need an uber-high end board and felt it was a nice fit, after bouncing back and forth between it and the Asus Sabertooth 990FX. After getting everything installed, computer booted without any problems, aside from having to reinstall the GFX drivers.

Getting to the point, I've made a habit of periodically checking SpeedFan for system temperatures during gaming. I noticed after a few minutes of playing Borderlands, the temps on one row were spiking as high as 52-55 degrees Celsius. I did some reading on this and found that the Northbridge on this particular board has tendencies of running on the hot side. As far as the readings from SpeedFan are concerned, I couldn't make any sense of them. The processor itself looks to be fine, with idle temps averaging around 10 degrees Celsius and load around 25 degrees, according to AMD Overdrive. The reading I'm unsure of is TMPIN1. Is it the sensor to measure the Northbridge's temperature?

What would be the safest operating temperature for the NB on this board?

Current Specs
Win 7 Home Premium
Western Digital 1TB Caviar Black
8 GB G.skill DDR3 RAM
Rosewill Capstone 750W PSU
EVGA Nvidia GeForce GTX 550 Ti
AMD FX-4100 Zambezi @ 3.6 Ghz

TMPIN0 is the system temp. TMPIN1 is the CPU socket, and TMPIN2 is the Northbridge, on that board. Anywhere in the 50c range is good, lots of people have seen 60-70 as well without many problems. The UD3 in your motherboard stands for "Ultra Durable 3" so this board is an overclocking/high temps centric board. It can handle those temps with ease.