We're in the process of adding Gigabyte's GeForce GTX Titan Black GHz Edition to our 2014 VGA Charts, which will facilitate a complete performance break-down, but I still wanted to touch on a normalized comparison in this review, also.
Additionally, I thought it'd be good to explore whether or not 6 GB of graphics memory makes a big difference in the benchmarks. Originally, it was believed that Nvidia's partners would start selling GeForce GTX 780 and 780 Ti cards with 6 GB, rather than 3 GB. There's currently one 780 from EVGA with 6 GB. However, plans for the 780 Tis were scrapped when it became clear they'd cannibalize sales of Titan Black amongst affluent enthusiasts.
GPU Boost Frequency Under Load
We've gone into great depth about how Nvidia's GPU Boost technology works in theory and practice, so let's compare the company's reference GeForce GTX Titan, an overclocked Gigabyte GeForce GTX Titan Black, and the overclocked Gigabyte card with its modified cooler.
The overclocked Gigabyte board with Nvidia's reference cooler hangs out well under its 1100 MHz ceiling. In fact, the average frequency barely hovers around 1050 MHz. The modified version is quite a bit faster, averaging 1150 MHz. That's a gain of about 100 MHz, with lower temperatures and less noise to boot. Nvidia's reference GeForce GTX Titan really can’t compete. The overclocked Gigabyte model with its WindForce cooler lands just behind the Gigabyte GeForce GTX 780 Ti WindForce OC‘s Boost clock frequency of almost 1170 MHz.
We’re using the 1080p benchmarks of our VGA charts at higher (in fact, the highest possible) settings for our normalized performance benchmarks.
Comparison between 1080p and 2160p: Are 6 GB Worth It?
If you go by the performance benchmarks, 6 GB doesn't appear necessary at all. There's barely a difference between the two configurations. This is complicated by the fact that a single-GPU configuration still can't really handle 3840x2160. In order to enjoy the highest resolutions and most demanding detail settings, you want a couple of high-end cards in SLI or CrossFire. To keep the comparison fair, I overclocked the modified Gigabyte GTX Titan Black GHz Edition with the WindForce cooler to the same 1020 MHz base clock speed as the factory-overclocked Gigabyte GTX 780 Ti WindForce OC.
The head-to-head comparison paints a sobering picture. Apart from double-precision compute performance (for the handful of folks who actually need it), a similarly-clocked GeForce GTX 780 Ti is clearly the better choice, especially since it's a lot less expensive.
Now, here's the wild card: 6 GB is very likely more important to an SLI configuration. I don't have the cards or the FCAT suite here to properly test such a decadent setup. However, I also know from Chris Angelini that a couple of 3 GB cards rendering cooperatively start to demonstrate stuttering artifacts at 2160p, particularly as you crank up the detail settings. In those cases, we think you'll lament the fact that there aren't any GeForce GTX 780 Ti 6 GB boards available.