Agp 3.0

[Nuclear Krusader]

I have been seeing the new mobos that pack this slots.

What are the differences between AGP 1.0, 2.0 and 3.0?

I know they are independent from the speed that is measured in X (i.e. AGP 8X).

Feel free to elaborate, a complete and very informative answer is what I'm looking for.

TIA

[MonkeyBlitch]

Higher data rate - The AGP 3.0 Specification increased the strobe rate from 266 MT/s with AGP 2.0 to 533 MT/s with AGP 3.0. This now doubles the peak AGP bandwidth to 2.1 GB/s.

New signaling scheme - AGP 3.0 uses the same connector pin assignment, as AGP 2.0 with a few additions. With the new signaling scheme, several signals are now inverted in order to reduce DC current flow. The new signaling scheme also uses a signal swing of zero to 0.8V.

AGP 8X Transfer Mode/AGP 3.0 Spec compatibility - Since AGP 3.0 uses the same 1.5V keyed connector as AGP 4X, AGP 3.0 motherboards and graphic cards can be designed to be compatible with existing implementations of AGP at 1.5V signaling.

Redefined signals - Two signals have been redefined and several new signals have been added in order to support the new signaling scheme.

Removal of High Priority and “Long” Type Transactions - AGP 3.0 does not support high priority transactions. This feature has been removed and therefore all transactions have the same priority. AGP 3.0 also does not support “Long” type transactions. The maximum transactions size initiated by a master is limited to 64 bytes. These changes keep the protocol simple and efficient.

Isochronous support - Isochronous data transfers guarantee to process a specified number of transactions of a specified size during a specified time period. This allows streaming applications a continuous data transfer.

Compatibility
AGP 3.0 video cards will allow backwards compatibility with AGP 2.0 (4X) motherboards, however, the card will only work at the AGP 2.0 spec, not 3.0. Even though AGP 3.0 motherboards will support AGP 2.0, some motherboards with the AGP 3.0 specification may only support AGP 3.0 and not both 3.0 and 2.0 in the future. Make sure you always check your motherboard manufacture’s AGP specification before purchasing your next video card.

AGP Spec Signaling Bandwidth Strobe Rate Speed
AGP 3.0 0.8 V/1.5V 2133 MB/s 533MT/s 4X, 8X
AGP 2.0 1.5 V/ 3.3V 1066 MB/s 266MT/s 1X, 2X, 4
AGP 1.0 3.3 V 533 MB/s 133MT/s 1X, 2X

[Nuclear Krusader]

Very informative. Thanks a lot.

[MonkeyBlitch]

Glad to help ya