The GTX 770 arrives to Challenge the HD 7970 GHz Edition – 25 Games benchmarked!

Overclocking, Power Draw & Temperatures

Overclocking

Overclocking the GTX 770 beyond the stock clocks are easy. No one should let the boost clocks intimidate them. Using EVGA Precision tool, simply push the sliders to the right as far as you dare and set the clocks and apply. No more shader clocks to adjust as the vRAM and the core clocks are easy to set.

The only differences with Boost 2 from the 600 series are in setting a temperature target.  We found in practice that Nvidia’s default choice of 80C is too low for Summer gaming and we experienced variability with our initial runs performing higher than later runs when the performance is throttled when Boost 2 lowers the clockspeeds in response to hitting the thermal limit.
We solved these issues by setting the power draw and temperature sliders to maximum – +106% power target and 94C for the temperature target – much as we do for AMD cards with PowerTune.  In this way, we find uniformity in our benchmark runs and less of a chance for Boost to throttle down clocks in response to a low thermal limit.  The maximum overvoltage which is allowed is +.12mV which we did not use at all in our benching.

As usual, we are not looking for the ultimate overvolted overclock with our VGA fan screaming along at 100%. We always test with our cards at stock voltage and with the stock fan profile so that our reader may have a good idea of midrange overclocking.

We finally settled on increasing the base clock by +90MHz over the base clock of 1046MHz and we witnessed 1215MHz as the regular maximum boost.  This is below the +175MHz we were able to achieve with our GTX 680 which topped out at about 1260MHz.

The GTX 770 fan speeds stayed low with temperatures in the mid-70s under load – definitely higher than the 50sC we experience with the GTX 680 which has a lower TDP.  However, even with the higher temperatures, the GTX 770 is slightly quieter than the GTX 680 and we notice that the fan speeds are more uniform with the newer card.

We did exactly the same thing with our PowerColor HD 7970. Its stock clocks are 925/1375 and we pushed them to HD 7970 GHz Edition clocks at 1050/1500MHz by simulating an always locked on 50MHz boost.  PowerTune is always set to maximum.

With our GTX 680, we added +550MHz to the 6008 memory clock and with the GTX 770 we were able to add +500MHz to the higher 7010MHz memory clocks.  The new DDR5 is very overclockable and just increasing the memory bandwidth has improved the frame rate in many games.

We always use EVGA’s Precision overclocking tool which recently added further over-volting for Titan and 700 series.  Moving up the power slider to 106% and the temperature up to the maximum 94C using EVGA’s Precision showed very little performance gain over simply setting the temperature limit to 85C.

Temperature

Our ambient (room temperatures) were fairly warm from 76-80F so as to approximate a warm late Spring day. Be aware that we used our Thermaltake Overseer RX-I case which has excellent airflow for even a full tower. The GTX 770 runs moderately warm at our overclock, in the low 80s C under load. If we did not increase our temperature target to at least 85C, we found that we often saw Boost throttle the clockspeeds to lower the temperatures.

You can see from the performance charts what effects increasing core speed has on the GTX 770.  We used Futuremark’s latest benchmark FireStrike to give relative performance and we were able to maintain stability with an offset of +125MHz core/+550MHz memory although we eventually settled on +90MHz core/+500MHz memory as absolutely stable across all benchmarks in all situations.

+600MHz began to artifact in Firestrike and no runs could be completed with the core boosted by more than +125MHz, even with additional overvoltage (and with the stock fan profile).

You can certainly see the effects of Boost throttling at a high overclock when the temperatures and power targets are set back to default.  And you can see the throttling becomes extreme when the Targets are lowered to their minimums.  And it is also clear that the GTX 770 needs the faster DDR5 to utilize it increased base core speeds over the GTX 680.

Noise

All the modern Nvidia cards are extraordinarily quiet for high-end flagship cards. The Fermi GTX 580 was already reasonably quiet for a powerful card, but the GTX 680 is noticeably quieter and the GTX 770 is quieter still. And we had to drop our overclock on our CPU and lower our CPU and case fans rpm to even notice the GTX 770 at all except when it was at full load.  The GTX 770 automatic fan profiles work well and needed no tweaking using our maximum overclock on each card.

It appears that Nvidia has especially tuned the GTX 770 to be quiet somewhat at the expense of performance. It will be interesting to see what cooling designs their partners implement.

Let’s head to the performance charts and graphs to see how the GTX 770 compares with the GTX 780, Titan, the GTX 690 as well as with the last generation dual-GPU flagships – the AMD HD 6990 and the Nvidia GTX 590 – as well as with the top video cards of this generation, the HD 7970 and the GTX 680.  We also added the GTX 670 and the GTX 570 to our testing bench for this evaluation.