Oh boy, oh, boy, This is it! This is why technology journalists get out of bed in the morning. The Evesham Axis 64 Decimator 78, oozes cutting-edge technology from every pore, some of it so new, it hurts.
Let’s get straight to the heart of the matter. The CPU at the heart of this machine is no less than an Athlon X2 4800+, the cream of AMD’s mainstream line-up. It boasts two cores, each running at a clock speed of 2.4GHz, with 1MB of Level 2 cache available to each, primed to eat up whatever you throw at it, whether it’s games, video or image work. But that’s not why we’re excited about this PC. Not today. Oh no... not by a long chalk. What’s really pushing our buttons are the two nVidia graphics cards running inside it. 6800 Ultra SLI? Pah! Old hat. What we have here are the new babies on the block – ladies and gentleman - introducing the GeForce 7800GTX.
Now we sadly only had a relatively short time to play with this PC, so we weren’t able to run our full suite of 2D tests. Instead, we concentrated on running as many of our 3D tests as we were able before we had to part company with the machine. But before we go on and talk about the PC in general let’s get a clearer picture of what nVidia is offering with the 7800GTX.
The GTX suffix is replacing the current GT but at launch will be the only variant available. We can expect a vanilla version and an ‘Ultra’ type variant to follow later though, no doubt at strategic moments to counter future products from ATI.
nVidia claims that the GTX offers around twice the performance of a GeForce 6800 Ultra, but our performance numbers will provide us with a better idea of whether that’s true or not. As well as the greatly increased 3D performance, nVidia is also touting improvements to its video abilities and that it’s optimised for the forthcoming Windows Graphics Technology standard, conforming to the Longhorn Display Driver Model, making it ready for the whiz-bang effects in Microsoft’s next operating system.
So what does it offer in terms of raw specs? Well though the 7800GTX is a new architecture, it is built from the same solid blueprints as the 6xxx series of cards. The transistor count has increased to 302 million, much of which is taken up by the 24 pixel pipelines – increasing the amount of pixels that can be worked on per clock. The 16 pixel pipelines offered by the 6800 Ultra doubled that of its predecessor, the GeForce 5900, so perhaps nVidia has a 32 pipeline card waiting in the wings. For now thoughit clearly feels that 24-pipes are sufficient. The number of vertex units has also increased from six to eight, speeding up geometry calculations.
The new GPUs are produced on a new 0.11 micron process, and not 0.09 as some had predicted. Though the more recent micron process would imply an increase in clock speeds, in fact, the increases on the GTX are marginal, at 430MHz for the core compared to 400MHz for the 6800 Ultra. This will be the default speeds for the cards, though different vendors will choose variations on this.
The newer manufacturing process does mean that the power efficiency is improved and it actually draws less power than the previous generation 6xxx. Indeed while nVidia recommends a 500 Watt power supply, the Evesham rig proved completely stable using a Tagan 420 Watt PSU. As with the current line of GT cards, the 7800GTX is single slot and though the heatsink/fan assembly is large, noise levels are reasonable.