PDA

View Full Version : AGP3.0 has 8x and 4x compatability but not 2x?



ricercar
07-08-2002, 02:38 PM
From Tom's Hardware, http://www.tomshardware.com/mainboard/02q2/020514/p4x333-02.html

"AGP 8x uses the same connector as AGP 4x, the only difference is that some pins have been reassigned in order to support the new signaling. As a result, you will be able to run all AGP 8x and AGP 4x graphics cards (at 0.8 V and 1.5 V) - but not AGP 2x!"

http://www.macgurus.com/ubb/hr.gif
Can someone explain this alleged incompatability? I don't understand why AGP3.0 is not compatible with AGP 2? and 1? speeds. I realize that AGP3.0 cards are physically incompatible with AGP 1.0 (3.3V) slots, but haven't seen aything to support AGP 3.0-2.0 incompatabilities aside from sideband vs. pipeline issues.

Apple marketing materials suggest that their GeForce4 cards are incompatible with AGP 2? Macintosh models, yet the NVIDIA GF4 data sheets indicate complete backwards compatibility with AGP 1?, 2?, and 4?.

------------------
ricercar

Everything seems like overkill until you get used to it. - Ironmac

[This message has been edited by ricercar (edited 08 July 2002).]