Palit GeForce GTX 680 JetStream review
Posted by Hilbert Hagedoorn on: 04/12/2012 01:00 PM [ 0 comment(s) ]
Technology and Specs
So then, it's time to talk business. The GeForce GTX 680 released today is based on the new Kepler GPU architecture. Interestingly enough it is based on the 28nm GK104 GPU which typically would have indicated a mid-range product. The 10" long GeForce GTX 680 boasts an impressive 1536 CUDA (shader) cores. The product is obviously PCI-Express 3.0 ready and has a TDP of around 195W with a typical draw of 170W. But let me first show you GK104:
NVIDIA GK104 Kepler architecture GPU
As far as the memory specs of the GK104 Kepler GPU are concerned, the boards will feature a 256-bit memory bus connected to 2 GB of GDDR5 video buffer memory, but later versions will also be available with 4 GB of VRAM. On the memory controller side of things you'll see very significant improvements as the reference memory clock is now set at 6 GHz / Gbps. This boils down to a memory bandwidth of 192 GB/s on that 256-bit memory bus. It's actually similar in bandwidth to the GeForce GTX 580.
An immediate difference to the GPU core versus the shader processor domain is that both will be clocked at 1:1, meaning both the core and shader domain clock in at 1006 MHz, that means that the 2x shader hotclock from the last generation products is a thing of the past. One clock to rule them all (well internally there are dozens of different other clocks really, but let's keep it simple).
With this release, NVIDIA now has the first series 600 cards on its way. The new graphics adapters are of course DirectX 11.1 ready. With Windows 8, 7 and Vista also being DX11.1 ready (well, Windows 7 and Vista will be once Windows 8 are released officially) all we need are some games to take advantage of DirectCompute, multi-threading, hardware tessellation and the latest shader 5.0 extensions.
For your reference here's a quick overview of some past generation high-end GeForce cards opposed to the new Kepler based GeForce GTX 680.
|Stream (Shader) Processors||240||480||512||1536||1536|
|Core Clock (MHz)||648||700||772||1006||1084|
|Shader Clock (MHz)||1476||1400||1544||1006||1084|
|Memory Clock (effective MHz)||2400||3700||4000||6000||6300|
|Memory amount||1024 MB||1536||1536||2048||2048|
|Two Dual link DVI||Yes||Yes||Yes||Yes||Yes|
For Kepler, NVIDIA kept their memory controllers GDDR5 compatible. Memory wise NVIDIA has nice large memory volumes due to their architecture, we pass 2 GB as standard these days for most of NVIDIA's series 690 graphics cards.
The hardware engineers of NVIDIA reworked the memory subs system quite a bit, enabling much higher memory clock frequency speeds compared to previous generation GeForce GPUs. The result is memory speeds up-to 6 Gbps. Each memory partition utilizes one memory controller on the respective GPU, which will get 256/512 MB of memory tied to it. There is word that a 4 GB version will be manufactured as well.
- The GTX 580 has six memory controllers (6x256MB) = 1536 MB of GDDR5 memory
- The GTX 680 has four memory controllers (4x512MB) = 2048 MB of GDDR5 memory
For this review we test and benchmark the Palit GeForce GTX 650 Ti Boost OC edition. The product comes customized with their own PCB design, a dual-fan cooler, 2GB of memory with both that memory and the core baseclock slightly overclocked.
Palit GeForce GTX 660 Ti Jetstream review
In this review we'll look at the GeForce GTX 660 Ti from Palit, it's their all beefed up version, the GeForce GTX 660 Ti JetStream version. The GTX 660 Ti again has been equipped with a JetStream series cooler yet which remains a 3-slot design. It runs at a core clock frequency of 1006 MHz, has a boost frequency of 1085 MHz and the effective memory data rate (192-bit) is 6108 MHz.
Palit GeForce GTX 670 JetStream review
We review the Palit GeForce GTX 670 JetStream graphics card. the JetStream version which comes pre-overclocked at 1006 MHz on the baseclock and an impressible 1084 MHz on the boost clock. More interestingly, the boost clock during our test sessions was actually closer to 1200 MHz most of the time (!). To give the card enough framebuffer to work with the cards are equipped with 2048 GDDR5 on a 256-bits wide bus. Palit clocks this memory at 6108 MHz.
Palit GeForce GTX 680 4GB Jetstream review
We review the Palit GeForce GTX 680 4GB Jetstream edition. Why 4 GB ? Well some of you like to game at extremely high resolutions or have 8xAA as a bare minimum. If a graphics card runs out of graphics memory it'll starts swapping frames back and forward in that framebuffer which decreases the overall framerate. So today we'll look at the 4GB model, we'll specifically place a focus at some tests at 2560x1600 with a good chunk of AA enabled to see what difference the extra 2GB graphics memory will bring us in terms of performance.