Both ATi and NVIDIA are delivering serious competition for one another with their latest generation of products. What was once known as the NV40, has become a number of high-end products. NVIDIA must cover every possible market segment if they wish to remain the biggest name in the graphics card industry. The end result being three unique NV40 based products; there is also the possibility of a fourth. Currently we have the GeForce 6800, GeForce 6800 GT and GeForce 6800 Ultra. The GeForce 6800 Ultra is NVIDIAs current flagship product designed to take on the ATi Radeon X800XT. However, ATi decided to offer a cut down version of their X800XT which we now know as the X800 Pro. The ATi Radeon X800 Pro is an exceptional product offering extreme performance at a reasonable price.

The GeForce 6800 GT is NVIDIAs answer to the Radeon X800 Pro; however its even more like its flagship product. The 6800 GT is the same product as the 6800 Ultra with the exception of a 100MHz lower memory and 50MHz core clock. This will naturally hinder the performance of the GeForce 6800 GT, but I imagine the decrease will be minimal. The GeForce 6800 GT will certainly be the preferred solution by most, given that the only difference between it and the 6800 Ultra is a slight decrease in clock speeds. However what will make it the preferred solution is its $100 US price saving over the 6800 Ultra. The GeForce 6800 GT core is clocked at 350MHz while the memory operates at 500MHz or (DDR1000).

Just like the GeForce 6800 Ultra the cheaper GeForce 6800 GT version features 16 rendering pipelines. The Radeon X800 Pro loses out here featuring just 12, this is 4 less than the X800XT. The GeForce 6800 Ultra/GT core is a 16x1/32x0 architecture and such a design does not make for a small chip. When compared to the NV35 GPU which was a 4x2/8x0 architecture, you can imagine how complex the NV40 design really is. The core is based on a 0.13-micron process consisting of 222-million transistors, making it more complex than the latest Pentium 4 processor.

The GeForce 6800 GT makes use of GDDR3, where as the standard GeForce 6800 uses conventional GDD1 memory. There are few differences between GDDR1 and GDDR3 with the major variation being their operating voltage. The older more common GDDR1 memory chips require 2.5v where as the newer GDDR3 chips want just 1.8~1.9v. This small improvement allows the chips to run at much higher frequencies, for example the memory has already been demonstrated at 800MHz which is effectively DDR 1.6GHz! However there is one drawback when comparing GDDR1 to GDDR3 and that is the CAS Latencys. Due to GDDR3 being able to operate at such extreme frequencies, the CAS Latency has been increased to maintain stability. Therefore at the same working frequency, GDDR1 will be ever so slightly faster then GDDR3.

This year I expect to see GDDR3 accepted much more rapidly when compared to GDDR2 last year. With GDDR2 in existence for over a year now, GDDR1 is still much more widely used. With the frequency improvements of GDDR3, it should no doubt be the number one choice for all graphics cards in 2004 and of course 2005. The GeForce 6800 GT utilizes a 256-bit memory bus and is capable of using a total of 256MB of onboard memory. As mentioned earlier, the specified frequency for this memory is 500MHz which in DDR terms, equates to a 1GHz clock speed. Today I will be reviewing the Gigabyte GV-N68T256D which of course is a GeForce 6800 GT based graphics card. Lets take some time to look at this solution in a little more detail...