GALAXY GeForce GTX 660 Ti GC 3GB Overclocking Review

We've evaluated the GALAXY GeForce GTX 660 Ti 3GB video card, now it is time to overclock it to its maximum potential with XtremeTuner Plus and find out how it compares to the GTX 670 and Radeon HD 7950. We will also find out if it is best to concentrate on the GPU clock speed or its 192-bit memory speed to get the best performance gains.


On August 16th 2012, NVIDIA launched the new GeForce GTX 660 Ti Kepler GPU based video card. We had the opportunity of evaluating a full retail GALAXY GeForce GTX 660 Ti GC 3GB video card at $339 featuring the new GTX 660 Ti. We found out that the GeForce GTX 660 Ti shares all of the features of the GeForce GTX 670 including CUDA cores and clock speeds. The only difference is that NVIDIA scaled down the memory bandwidth to a 192-bit memory bus taking bandwidth from the GTX 670’s 192GB/sec to 144GB/sec.

Despite that reduction in memory bandwidth our GALAXY GTX 660 Ti GC 3GB video card provided to compete well, not too far behind the GTX 670. In most cases it outshone the Radeon HD 7950, and in all cases it provided a big upgrade path from past generation GTX 560 Ti and GTX 460. The one area of the video card we weren't able to get to was overclocking. We wanted to hold off on overclocking as it deserved its own article and focus. Kepler has been an excellent generation of GPU from NVIDIA in terms of overclocking. The GeForce GTX 670 and GeForce GTX 680 have been excellent overclockers, often reaching as high as 1.3GHz or higher on custom video cards so we have high hopes for our Galaxy GTX 660 Ti GC 3GB.

GALAXY has built this GTX 660 Ti video card with the goal of overclocking. GALAXY has provided an 8-pin and 6-pin power connector required for this video card rather than the reference dual 6-pin connectors. By doing this GALAXY is ensuring more stable power for the card. On top of that GALAXY has designed this video card with a full-length PCB for better layout and signal pathing. You will notice that the GTX 670 actually uses a shorter PCB in the reference design, the 660 Ti does as well, but GALAXY went that extra step. GALAXY is also using "Thru-board ventilation" near MOSFETs for better component cooling. GALAXY is also using high quality shielded inductors. In terms of power components GALAXY is using a 5+2 phase power supply versus the 4+2 in the reference design, for a more stable current. And of course, GALAXY has a custom heatsink/fan that keeps the GPU very cool in our testing.

We also want to answer a very specific question in this evaluation, "Is it better to overclock the memory or the engine clock speed?" since this is a 192-bit memory bus video card? The reason why we ask this is because with the GTX 670 and 680 we know that overclocking the core frequency provides more of an impact on performance than overclocking the memory. However, since this is basically a GTX 670 GPU with a narrower memory bus, does that mean the memory is more important to overclock? We want to find out what exactly is best for this GPU so you can have the most luck with getting the best gaming performance out of the GTX 660 Ti on your own. Then we will overclock it and see how it does compared to a GTX 670 and Radeon HD 7950.

XtremeTuner Plus

The key to a good overclock is also good software controls. Up until now, we haven't recommended GALAXY's XtremeTuner overclocking software. We've had poor luck with it in the past. We had found that in the past, it’s on screen display was broken and not working for us in games. We also found the past XtremeTuner clunky with messy controls. We referred instead to other third party utilities when overclocking GALAXY video cards in the past.

That has all changed. GALAXY has a brand new completely re-done XtremeTuner it calls XtremeTuner Plus, and it is currently in Beta form. You can download and read all about it here and download version 2.0.0, which we used for this evaluation.

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The default interface shows your GPU temperature on the top left, and your fan speed on the top right for quick reference to make sure your card isn't overheating. In the middle you can easily see the power target and GPU and memory offsets. Towards the bottom is where you change your power target slider, and on our card here we can take it up to 125%. You can also change the GPU voltage where supported, and on our card we could take that up to 1.175v. You can change the GPU and memory offsets here as well. You will also find the framerate target which is a unique feature supported on NVIDIA GPUs of this generation. You can also set a manual fan speed, or leave it at auto.

One of our major complaints about the previous version was its non-working on-screen display function. We use this all the time for our video card testing because we need to see in real-time what the GPU frequency and memory frequency and temperatures are when we test every video card. We'd often have to refer to third party utilities running alongside XtremeTuner in order to see this real-time data. Now, it works! In the settings menu just check what you want to see, clock speeds, temperature, fan speed and framerate even. However, while it works finally, it is quite limited in the data it can show on-screen. MSI Afterburner for example has a lot more information about the video card it can display in real-time, along with showing multiple-cards at once. So while it works, it is more limited than other programs out there.

Thankfully using the program is quite easy; you simply raise the sliders to where you want those and then apply the settings. You don't have to reboot. You can save any combination of settings as a profile that is as easy as clicking on to apply. There is also a monitoring window that you can open and let it monitor GPU clock, memory clock, temperature, fan speed, GPU voltage and fan speed RPM over time. Our one gripe with it is that the actual sliders and font sizes for the offsets could be bigger as those can be a bit hard to see. That is pretty much it in terms of feature support. Again it's not as in-depth as some other utilities out there, but it gets the job done and allows the most important overclocking options.

Test Setup

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We are using the same drivers we used in the original evaluation for all video cards. Our goal today is to first find out if overclocking the memory or the engine clock is more important on the GTX 660 Ti. Then we will overclock both and see how it compares to a GTX 670 and HD 7950.