nope, AGP on the riser.
Unfortunately that's tantamount to PCI. It's possible that MorphOS doesn't do quite as well with only a bridged fake AGP port as it would with a real AGP adapter, although the only system bplan have ever made with "real AGP" has been the original Articia S Pegasos I. Simple benchmarks showed that bandwidth across this bus was not much better than PCI and in any case the 66MHz PCI bus provided on the Discovery II for the Pegasos II, and the Efika PCI bus, outperform it by a long way.
The problem comes when you run out of memory; PCI transfers cannot be pipelined and there is a seperate address and data tenure for every section of data meaning transfers can take twice as long as on AGP, which uses sideband addressing (for every 32-bit word transfered you can send a 8-bit address portion, this increases the performance of bursts).
However most AGP data is transferred in a mode, which is exactly the same as 66MHz 32-bit PCI, for all intents and purposes. Speeding up these transfers requires double- and quad-pumped buses, and sideband and pipelining gets turned off.
If you only have a 32MB or 64MB card then you may have many open screens with many windows and run out of memory, then the bus bandwidth will really show since textures have to be manually uploaded and downloaded. AGP can access through the GART any system memory which means texture management can easily pick data which will be rarely used and simply not upload it to the card, or push rarely used data out to make sure it is not in the way.
This may be the case if you put a screen to back, or something. If it is not being displayed you could get away with pushing all of it's graphics out to main memory.
On the Efika, only having 128MB of real memory is going to really cause a problem here. I would not recommend you enable it unless you have a 128MB graphics card.
Matt Sealey, Genesi USA Inc.
Product Development Analyst