On March 22, Nvidia unveiled its first "Kepler"-based graphics card. Branded as the GeForce GTX 680, the card is powered by a 28nm GPU codenamed GK104 that crams 3540 million transistors into a 294mm2 die. That's an comeback from the 40nm GTX 580, which has 540 million fewer transistors yet is most three times larger, and information technology partly highlights the overall goal of Kepler: improved efficiency.

This refinement is visible in all aspects of the carte, not to the lowest degree of which is raw performance. Based on Fermi'south second-generation Streaming Multiprocessor (SM) architecture, the GTX 580 has 512 CUDA cores, 48 ROP (Raster Operations) units and 64 TAU (Texture Addressing Units). The GTX 680 ramps that up to a massive 1536 CUDA cores, 128 TAUs and 32 ROPs, bringing loads of horsepower to the race.

A few changes have been made to the clock speeds while the Shader clock has been removed entirely. Instead, everything at present runs off the cadre clock, which now besides features what Nvidia calls a "Boost Clock," a engineering akin to Intel's Turbo Boost. By default, the GTX 680 comes clocked at 1006MHz -- already 30% higher than the reference GTX 580 -- with a dynamically irresolute Boost Clock of 1058MHz. Meanwhile, the GDDR5 retention frequency has increased l% from 4008MHz to a blistering 6008MHz.

With the Radeon Hard disk drive 7970 only existence on average nine% faster than the GTX 580, AMD priced itself into a corner with its flagship originally gear up at $549. However, the company responded quickly by reducing prices on much of its HD 7000 series, putting the HD 7970 at $479, just under the GTX 680's $499 suggested rate.

We were surprised AMD acted and so fast. Although the GTX 680 is quicker than the Hard disk 7970, Nvidia'southward bill of fare is withal merely available in limited quantities -- if at all. Equally of writing, Newegg doesn't accept a single bill of fare available and Amazon has depression stock warnings on most GTX 680s. While Nvidia struggles to meet need, board partners have been busy crafting custom cards. Because nosotros didn't go a reference sample last month, our GTX 680 review will showcase one of the special edition products instead, run across the Gainward GTX 680 Phantom...

GTX 680 Phantom in Particular

A calendar week afterwards the GTX 680's release, Gainward unveiled its elite Phantom edition bill of fare, touting a re-worked PCB with an upgraded power stage, mill overclocking and a massive triple slot cooler -- the last of which is the nigh noteworthy alter. Although Gainward featured its Phantom cooler on some GTX 500 serial cards, the GTX 680 is the showtime to marketplace with the company'southward second-generation solution.

The Phantom II features the same elegant design as its predecessor, only delivers meliorate thermals while making less racket and has a sturdier construction. It's different any triple-slot libation we've encountered before every bit its heatsink features five 6mm heatpipes that extract heat from the base and evenly distribute information technology throughout the heatsink. The most unusual part of this design is the fans, or rather their location.

Whereas fans are typically fastened to the top side of the heatsink, Gainward has instead embedded 2 extremely quiet 80mm PWM fans directly inside the heatsink. The company claims that its factory-overclocked GTX 680 is half-dozen degrees libation and xi.5dB quieter than a reference GeForce GTX 680. This is specially impressive when yous consider the efficiency gains Nvidia made with the stock design.

The heatsink measures 225mm long, 70mm wide and 40mm alpine (8.85in x two.75in x ane.57in). It features a black fan shroud that forces the 80mm fans to draw air in through fins above them and push it over fins below them at the same time. Moving past the heatsink is a black aluminum heat spreader that engulfs the top side of the card and cools the viii 256MB GDDR5 memory chips forth with the vi-phase PWM.

Past using a vi-phase pattern, Gainward includes 2 extra phases for power delivery to the GPU, which should amend operation under heavy loads and assistance in the cards overclocking abilities. Not only is the overclocking potential of this card improved but so is its efficiency while the choke dissonance and EMI noise also be reduced.

Speaking of overclocking, Gainward has done a little bit of the heavy lifting past pushing the core clock from 1006MHz to 1084MHz, a mild eight% increase, while the Boost Clock is increased from 1058MHz to 1150MHz, a ix% increase. The GDDR5 operating frequency has likewise been raised 5% from 6008MHz to 6300MHz, meaning the memory bandwidth has been boosted five% from 192.2GB/s to 201.6GB/south.

The rest of Gainward's carte remains fairly standard, including a pair of SLI connectors, 6-pin and 8-pin PCIe power connectors, and an I/O panel configuration consisting of HDMI, DisplayPort and 2 DVI ports.