I want to safe overclock for my EVGA gtx 970 SSC ACX 2.0

Some may differently but gpu's are much more sensitive to overclocking than cpu's so it is my opinion to get liquid cooling or leave it stock especially a top of line new one.
Now if it was a old one and you where running pretty cool but needed some extra performance I would say go for it.

Well just like cpu's it is a luck of the draw, you could have a lot of oc headroom or none. If you want to go ahead with trying start with 10mhz at a time and watch temps.

What res are you at? because your 970 should be getting the job done for you.

Pretty sure EVGA covers overclocking in its warranty. I got my clock up to +120 and +140, 110% power and kboost on. I can get to 1.5ghz on some games but it isn't completely stable, so I just stick to that clock I just posted.

Its a really small performance increase especially if your at 1080p

no need to run such high frame rates.. if your monitor is 60hz than you can vsync and hold a constant 60fps witch is perfect.
as for tomb raider it is optimized for amd gpu's so turn off aa and see if you can hold over 60fps.

I think your expectations are a little high.. overclocking it wont make you hold over 60fps in tomb raider with aa on.

up to you

Only worry if it is running too hot. Just look up a guide on how to properly oc your graphics card.

I do not have a water block, only using the beautiful ACX 2.0 cooler with its monstrous fans. I get over 1700 MHz at times, while never exceeding 45 degrees centigrade. It's a truly a beautiful overclocker. I just bought it a few days ago, I pushed it a little hard earlier and it crashed on me. But starting out, I suggest you use Precision X, rather than ANY OTHER overclocking utility, as they are not designed for your card and may have compatibility/ stability as I have learned from experience with MSI Afterburner. But for the best results to start, I have my SSC 970 clocked with a +100MHz clock, and +100 MHz memory clock, with +6mV, then left everything else alone. Going higher may cause instability, this is the most stable overclock I have found myself, I suggest you try it and let me know how it works for you.

i have finally achieved an overclock that im more than happy with now after getting my team dark pro 3333mhz memory to overclock to just under 3000mhz stable no matter what i throw at system. took me a little bit to figure it out. once i did for some reason the gpu and gpu memory now achiev +100 and +100 with just +1 volt increase and +1 wattage over for a gain of 10-11 fps in the division with all ultra at 1080p every setting on high as possible. no vsync on thats it. temp never goes over 57celsius with fan set to 70% run it went from 32-34 fps to 46-49fps just from overclock pretty impressive. really looks awesome now and pretty smooth.
i was losing hope with this asrock pro 4s mobo i7 6700 and 8gb team dark pro ddr4 3333mhz and evga gtx 970 ssc acx 2.0 system i just built. finally can rest a little easier with what i got for the money. it runs unigine valley 1080p highest settings from 47 fps -125fps depending on scene but usually around 55-60fps

sorry gpu running at constant 1631 mhz and memory at 7210 mhz

Maxwell responds to heat poorly. The hotter they are, the lower they'll boost. Keeping them cool is paramount. So, yes. Higher ambient temps will affect your overclock in an adverse way.

Got any screenshots of that 1700+ core clock? = ) That's pretty amazing.....

Consider this: I have owned many many gpu's I have 2 nvidia 6800s that i purchased when bf2 came out! thats old. The first gpu i ever got was actualy not a gpu but a graphics excellorator. the 6800s still work perfectly. I never ever oc'd them. My brother is well off with a very very good job and makes excellent money. He buys GPUs and OC's them with MSI afterburner or other Windows GUI based OC utility . he uses effective cooling and he never seems to have any issues. then new stuff comes out and he replaces his GPUs. He has given me a total of 3 sets that he ran in SLI and an individual card from a rig he built that was not SLI and was hella super expensive.. i cant rem what it was and am too lazy to go look. He also built medium machines using cards like enthusiast GTX 460's. SO, to answer your question here is what happens. The cards I have purchased have NEVER burned out. The cards my brother gave me have ALL been OC while they were in his machine. I get them, they run fine for 3 - 18 months and burn out! I have fixed them by removing heat sink and compound and any plastic, preheat oven to 385 and with the chips UP - i place the board on a cooky sheet with 4 balls of aluminum foil to support the card so it never touches the pan. ( if you bake your gpu with the chips facing down- they will fall out of the board! - instant nightmare) Google baking cards. Every time I have done this to a card that has been burned out - it has worked. HOWEVER - it does not last. Some of them i had to re- bake after just a few weeks while others have lasted 6 months. But out of all of the 5 cards i have baked.. every one of them had to be baked again. So, OC your card via increased voltage will diminish the longevity of the card IMO. Some cards are built to OC. Maybe those cards will last. I am not a big fan of OC'n GPUs.But out of curiocity I have done it before using nvidias old "Ntune" or MSI after burner and a few other utilities but just to see what I could get for performance gains. I am not sure if OC'n them reduces the cards life because of heat or for some other reason caused by increased voltage. So if you can put a REALLY good cooling system on it... maybe that will be the answer. Still... just how much of a gain can you get? maybe you need that extra gain just to put you over the edge to "Playable" but IMO... don't OC GPU unless you have to and you have sufficient cooling