MrHamm

Hey Donta1979.
I live in Canada =( But it has been hot recently.

Air flow "should be good" I clean my interior every month -fans, filters, blowing it out with a air compressor can. Never seen even one dust ball. Just a thin layer of dust from a month of use.

I wouldn't be comfortamble replacing the thermal compund. Wouldnt know what I would be doing....
V-Sync is on -GPU is at 50% and Temps at 75C.

Should I be worried?

Anyone can answer my questions on OP?

do this on your fan curve

 
Re-timming the gpu is no different than timming your cpu. Just have to be careful, and use a tim like MX 2 that is not conductive.
As for your questions
1. How much performance gain on average would I be seeing? (I see about 10% on forums) –I know it’s different on every card. –but average.
a boost from what? oc vs no oc? if so depends on the card and how well it ocs

2. What about life expectancy in regards to OC vs. Non-OC
depends on heat, on both. Along with the card there is no guanteed time frame. Its like asking a doctor how long your going to live with nothing wrong with you.

3. Do I need a Cooler like I did my CPU?
Thats up to you. Antec makes a sweet liquid cooler for your card.

4. I read that it “throttles back” when it reaches 70C? When I play D3 running Temperatures is already 75C. Is that normal? Does that throttle back already? I’m confused about this…
Yes they do, it downclocks at 70c. 75c depends on your ambient temps.

5. What does Back plating do?
Looks nice maybe lower temps 1-2c

6. I can only seem to find GTX670 OC’s steps –would it be the same as GTX680?
Use this its in my sig and its in my driver post stickied at the top of the 600 series section here on the forums.
600 Series Overclocking
Read this Guide from Guru3d GeForce GTX 680 Overclock Guide


7. Will updated drivers mean I have to OC again?
Sometimes depends on the drivers, but no not always.

8. Is everything done on Precision X? IF not what else?
you can use precision x, or rivatuner, or afterburner, its up to you what one you use

9. Warranty with OC-ing using Precision X?
As long as you dont cause major physical damage to your card.

10. Am I missing anything?
Nope

11. Links? with step-by-step for a noob?
http://forums.evga.com/tm.aspx?high=&m=1519930&mpage=1#1519930 
 600 Series Overclocking
Read this Guide from Guru3d GeForce GTX 680 Overclock Guide 

your temps disconnect a monitor... and the dips in your fps disconnect a monitor, get a cheap gpu to run an alternate display if you dont like the heat or dips in fps. your running a high res monitor with a 1080p display your taxing your card... So are your temps normal with a second monitor? yup, performance dips yup you have a second display your pushing alot though your card. Also at the resolution your playing at do you have a 4gb card or a 2gb card? 
 
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