About the PPU
The AGEIAT Physics Processing Unit (PPU) has been compared to 3dfx's launch of a 3D accelerator, and rightly so. As with 3dfx, AGEIAT has had the tough task of convincing consumers that this product is a must-have, while at the same time convincing game developers that the consumers of the future will regard this card as a common item.
In other words, AGEIA needs to convince both parties seperately, blindly hoping that the other part will also follow. A tough job. But what can AGEIA use to convince people? Perhaps the PPU itself?
The PPU is a very large chip. The 125 million transistors no longer makes a stir, the transistor count is much higher nowadays. The closest card, number-wise, is the old Radeon 9800 XT, having 115 million transistors.
The AGEIA PPU is made using a 130 nm process, the same technology used by ATi's newest chips. nVidia is well on the way with their 90 nm process, but AGEIA has sensibly chosen to use a well tested process to keep yields up.
To produce the chips AGEIA are being helped by TSMC.
The actual clock frequencies are a well kept secret, but the chip is equipped with a heat sink and a 40 mm. fan, so there is noticeable power consumption. The heat sink gets warm after long use, and the fan is not temperature controlled, it spins happily no matter the load. The fan can be heard, but it's not like the vacuum cleaner noise known from high end graphics cards.
The AGEIAT reference card has a dark blue PCB measuring 99 by 167 mm, somewhat like a Radeon 9600 or a Creative Soundblaster X-Fi card. Unlike those cards we have a good amount of RAM to use. AGEIA has chosen to use GDDR3 RAM, and the BFG test card has 128 MB of RAM split in four 32 MB modules. They are not covered by the heat sink, but are only cooled by air from the fan. Then again, GDDR3 modules does not consume much power and hence they don't get hot - not as hot as the PPU, anyway.
The 128 bit bus width to the PPU results in a memory bandwidth of 12 GB/s, which doesn't seem like very much, but ought to be plentiful for physics calculations.
For testing the card, AGEIA has suggested that you use a dual core CPU, which is increasingly becoming the norm. One reason that AGEIA is very attentive about this is that the PPU will cause an increased CPU load.
Normally, the graphics and composition of a game will be a joint task for the CPU and the GPU, with the CPU delivering data to the GPU, which in turn sends the processed data to the monitor and thereby the end user. With the use of a PPU, the process still starts with the CPU, but the data are now sent to the PPU for calculation. They are then returned to the CPU, which sends them on to the GPU, and in the end the final results are sent to the monitor.
Of course a very simplified description, but the point is that the CPU gets a higher workload, and therefore dual core processors will get an edge.
Driver-wise AGEIA still has some work to do. First and foremost you're limited to 32-bit operating systems using the current driver (version 2.4.2), but AGEIA says that support for Windows XP 64 is just about done. Another problem is that the installer refuses to install an older driver over a newer one, when using the otherwise very decent installer.
Instead you need to manually remove the new driver and install the older one.
Not a big problem, but slightly annoying when the driver installation is otherwise very simple.
But AGEIA should also be commended for the ability to have a new driver automatically remove an older one, so you don't have to mess around with third-part uninstallers, driver removers and what have you. Both ATi and nVidia could learn something here.
Many thanks to Klavs S who kindly summarized the above.
