AMD releases 'world's fastest' graphics card
One board, two GPUs.
AMD has launched its two-GPU Radeon HD 4870 X2 graphic card, as expected, with a host of suppliers offering boards based on the design.
AMD claimed it's the "world's fastest" graphics card.
The first in our in-tray: Sapphire's HD 4870 X2. Both GPUs pack in 800 unified shaders in cores clocked at 750MHz. Each connects to 1GB of 900MHz GDDR 5 graphics memory, linked over a 256-bit bus.
Sapphire's HD 4870 X2: world's fastest?
The two-slot, actively cooled card sports the usual TV-out port and a pair of DVI slots - Sapphire includes adaptors for VGA and HDMI.
The two GPUs operate co-operatively using AMD's CrossFire X technology. Put two of the new cards in a system with a suitable motherboard, and all four GPUs can work together to render scenes.
The HD 4870 X2 is available from today at the $549 (£288/€369) price point. Gamers on a budget may prefer to wait until September when AMD will roll out the $399 (£209/€268) HD 4850 X2
The 4850 X2 uses the same GPU as the 4870 X2, but clocked to 625MHz. Boards will contain 2GB of GDDR 3 memory.
That's right... but wait until they roll out the blazing 6MHz clock... I hear you'll actually have a 24 BIT address space with that sucker! Woohoo!
...640k will be all the RAM you will ever need.
Because the limit only kicks in at 4gb using a 32-bit operating system. Explained another way:
512MB system ram + 512MB video ram = 1gb total ram. Under the 4gb limit, so perfectly acceptable.
4gb system ram + 2gb video ram = 6gb total ram. You'll see 2gb system ram and 2gb video ram. 2gb system ram will sit there doing nothing.
2gb system ram + 4gb video ram = 6gb total ram. You won't have any system ram to play with, which is a Bad Thing (tm).
Where we've produced this 4gb ram limitation comes from 2^32 which is 4294967296 bytes or 4194304 kbytes or 4096mb or 4gb.
Hope that clears things up for you.