Galaxy NVIDIA GeForce GTX 680 Overclocking Guide & 7970 Performance Review Linus Tech Tips
Linus Tech Tips
·Linus Tech Tips
·2012-05-07
·
2,365 words · ~11 min read
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the Dark Art of overclocking so the GTX 680 is to my understanding fairly over
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over overclockable but I haven't seen any numbers yet so I'm going to be using
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a retail sample so this is probably going to be the only review that's up on
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launch day of the GTX 680 using a retail
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non handpicked board and uh we're going to see how far it goes and how well it
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can compare in terms of performance to the highly overclockable
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hd7970 from AMD so I've already got a
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lot of my numbers prepared here uh I have my stock speed 680 results I have
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my doc speed 7970 results then I have my
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680 OC results still to fill in because I have not yet begun overclocking and
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then I've got my 7970 OC results which are based on uh basically maxing out the
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overclocking within the Catalyst Control Center so we were running at uh oh shoot
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what was it just right 1.125 GHz on the
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processor and then uh 6.3 GHz on the
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memory so this is one freaking fast card
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and I am very very excited to see what
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we can get out of its main competitor the GTX
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680 here you oh yeah I'll be having a right so guys I'll be having a look at
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not only the performance but also the difference in power consumption from
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overclocking these cards so you can see there was uh definitely an increase an
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increase increase uh from the stock power consumption to the overclock power
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consumption I'll also be looking at how temperatures are affected because I've
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got all of my Baseline readings done so stay tuned guys we are going to be using
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EVGA Precision which at launch is the only overclocking application to support
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the 6 I'm more of an MSI After Burner guy
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myself I love their oh yeah see it's not going to work um I love their simple
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interface and I'm just very used to it I like the way they do their graphs but
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since Precision is what we're using Precision is what I will have to figure
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out how to how to work so stay tuned guys let's see how this goes well I
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guess we better do a basic rundown of precision X first so number one is that
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it has integrated voltage adjustments for the GPU so you can actually slide
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these to where you want them to go
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you can press set I'm not going to be changing any voltages I did not change
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voltages on the 7970 so I will not be adjusting voltages on the GTX 680 for
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the sake of this basic overclocking guide you guys want to turn up voltages
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on your CPUs be careful in terms of your cooling be careful not to fry your GPU
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because it is a very expensive mistake to make and while yes turning up
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voltages may not affect it in any way this is a new graphics card on a new
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manufacturing process there are no guarantees that it won't break your card
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whether it's um today or tomorrow or 2 months from
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now so maybe let someone else be the guinea pig Okay so we've got a
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performance log frame rate target which is this kind of neat thing right here we
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can enable this to set a Target FPS which is interesting because it seems to
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be related to the fact that the GTX 680
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dynamically scales its power consumption which is I don't know probably here
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somewhere okay don't see it uh but it
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scales it power consumption with its GPU clocks in order
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to achieve the optimal heat output to well to stay within the uh the power
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Target and heat Target that it was designed for so in order to get any
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serious overclocking done you're probably going to want to adjust your power Target so I'm going to go ahead
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and tell it pretty much I don't care what kind of power Target you reach as
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long as we're not turning up any voltage okay so that's one thing we've also got
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monitoring of temperature monitoring of fan speed this is cool you can use this
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software to set up a fan curve I love
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fan curves I think they're amazing I think giving users the control to say
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okay yeah I'm comfortable you know with really low fan speeds up to 70 degre 70°
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and then I want it to ramp right up to 100% get it cooled back down if you want
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it to work that way you can totally make it work that way so I'm going to turn that off adjusting voltages aha GPU
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clock offset so let's talk about GPU boost so
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the basic clock here so that's at about
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1 GHz 1,00 6 MHz or something like that
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and then the Boost clock at 1056 or something along those lines those are
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both clock speeds of your GPU
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so you can you can set an offset so what
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that means is the offset until it detects that it has extra TDP room extra
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power room in order to uh boost itself
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up from the offset that you've set so
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for example if I set the offset at 100 MHz and I know this GPU is probably
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going to be good for 100 MHz otherwise I wouldn't set that you should probably only go up in increments of like you
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know 15 to 25 go ahead and apply that you can see those dials are hopefully
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going to move in some way or unless that's just showing the uh the base
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default one okay cool
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interesting maybe we'll just get started and see how this
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goes okay but either way that's how offsets are supposed to work so as it
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needs more power it can boost itself up
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and uh you're just setting up what the
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base GPU clock will be and it'll Boost from there that's sort of the point okay
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guys so I see how this works now while I don't recommend using furmark for any
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kind of extended period of time it's been handy for me for this because it's
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allowed me to uh examine how the here
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with the performance log I can see the percentage of power that the board is
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using please Focus there we go um compared to see we've hit 132 which is
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the the maximum I was able to set for the power Target compared to what the
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GPU clock is actually running at so 11:45 is what we seem to be peaking at
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which is actually ah 1172 is our 100%
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Peak so that's uh we should be somewhere in the neighborhood of 106 + 153 so what
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is that uh or 1,6 + 153 so
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1161 something like that so yeah you can see we're we're popping up there once in
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a while but not staying there consistently so I'll have to look at how
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performance is actually affected but it looks like the way the overclocking
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works at least with Precision is that we are pretty much just overclocking the
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Boost clock and I don't see a way to
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adjust the base clock although because yeah obviously I can't find uh any
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manual or instructions for this right now but if I it turns out that I'm wrong
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then I apologize and guys please leave a comment and let me know but there we
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have it so let's see what kind of a performance Improvement we get by
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increasing the turbo GPU boost clock
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offset on the GTX 680 well I can see
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this causing some confusion so due to the way GPU boosts uh Works where it
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turns up the GPU clock if it has the available power headro um if you turn
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the overclocking the offset up past where it's capable of throttling to it
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looks like performance does not continue to scale so you can see we have a score
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of 3167 so I'm I'm going to go back to my spreadsheet now when I was at 153
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offset we were able to score
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3488 on the extreme preset in 3D Mark 11
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however what you guys will see is 3172 so this is almost exactly the same
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as what I got with my stock configuration on the GTX 680 so it looks
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like once we turn it up past the threshold it doesn't necessarily scale
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100% correctly now this is an early beta version of precision X and like I said I
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have no instructions so I'm not even 100% sure if I'm doing it right but I'm
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going to put it back at the setting I had before and run it one more time to
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see if I can get my overclocked setting dialed in here so now we see an even
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higher score so this is at uh plus 153
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so you can see we're getting about 1250 MHz when the benchmarks are actually
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running and we're seeing about a 100ish
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102 119 126 so we're seeing pretty close
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to the power threshold that uh that we've said over here in some strenuous
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situations so let's do some real world benchmarking and find out how this
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um GPU boost overclocking actually works
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now I would really prefer if they made some tweaks to the to the interface here
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allowing you to boost up this base clock rather than only the Boost clock so that
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you have at least some idea of a baseline that you're running at uh
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without it doing any like funky scaling back and forth but maybe that's
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something we'll see in a future revision hard to say let's check out the real
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world performance perance uh so this is weird check this out guys so with the
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overclocked settings running on the GTX 680 I'm not getting that weird
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flickering that I was getting in Skyrim with it at stock speed so
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um yeah I don't know what to say it seems to have kind of healed itself
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anyway I'm just finishing up my overclocked settings benchmarking and
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I'll be done shortly so in conclusion even after overclocking both of the
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cards the GTX 680 is still the winner
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and once I get the hang of overclocking it it might actually be a winner by a
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more substantial margin so I have a game running in the background so this shows
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what my final overclock ended up being 145 this was stable in all of my gains
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you can see the fluctuations in the clock speed as well as the fluctuations
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in the peak power consumption according to the uh Power Target up here so um I
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mean yeah I think there's probably still some refinement to be done to the
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Precision X tool or whatever other tools end up becoming popular with these cards
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but let's talk results for a little bit here so idle power is up about 10 watts
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versus the stock clocked card and then
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um idle temps are around the same 3D Mark 11 uh we saw up to
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3572 3D marks um although at the same
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clock speeds we saw scores as about 100
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marks lower even so there seems to be some inconsistency in the scores
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although we saw fairly consistent improvements across the board at
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actually what I'm going to do is I'm going to um hide all this other stuff so
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we saw fairly consistent improvements across the board so here is the aha so
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we saw about a 7 8% Improvement in
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Battlefield 3 then in crisis 2 we saw
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yeah very little there so about a 4% Improvement 3 and 1/2% Improvement
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something along those lines Witcher 2 we see about a you know % Improvement
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something along those lines or like six or whatever that works out to uh power
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consumption is a little bit higher across the board using the same
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methodology I was using in my original performance review to measure that um
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see this is weird Dirt 3 actually went down a little bit in terms of average
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frame rate although power consumption went up substantially Batman Arkham City
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is up significantly I'm probably going to have to rerun these numbers and I'll
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do an annotation on my uh original review video if there's anything foul
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about them because you can see that power consumption number is low that could also have to do with GPU boost
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scaling back the power and scaling back the performance Skyrim we see uh NVIDIA
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is definitely the king here and we see a
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very moderate performance Improvement in Skyrim that is what I would consider to
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be within the margin of error for this test so we didn't see much of a
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performance boost there however it is still good enough to beat the radon
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7970 overclocked so there you have it it
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guys my GTX 680 let's call this preliminary overclocking video because I
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don't think we can call these results final but this is what I've got ready
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for launch and hopefully I'll be able to do a followup at some point let you guys
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know if there are any changes to my overclocking methodology with this card
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here here I am finishing up my benchmarks and I'm probably not done for
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