Pegasos2 Specifications at IBM

[Casper]

Well, speed and the number of ports are two different things, but anyway the performance comes out of the GFX card. It would be the absolutely technical overkill from a component requirement (and cost) to have more. Today's graphics cards do not use the AGP bus to move texture data to the graphics core. The textures are stored inside the graphics card RAM. The only data that is transferred to the card are the coordinates for the graphic core. For this task the current bus speed (AGPx1 = PCI66) is ok. This bus can transfer 266MB/s, that is about 40M coordinates for textured triangles. With a estimated size of 20 pixel per triangle you can draw 800M pixel/s on the screen. With a resolution of 1600x1200 this is about 400 frames per second. You will NOT find a monitor that is capable of doing this.

This is only half the truth. You forget that you actually have to get the textures uploaded to the graphics card memory. As Hammer points out there are many games today that use many high-res textures in a scene. Add to that that many newer games use mulitexturing (i.e. several layers of textures on the same polygon to achive e.g lighting and bumpmapping effects). So there's a whole lot of texture data that needs to be transfered to the memory for a complex 3D-scene.

[Casper]

@Neko

AGP 8x and so on is a pandering to the onboard chip manufacturer, where video RAM *is* system RAM and is *always* transferred across the AGP bus. If you noticed, these chips allocate some pitiful 16MB (4, 8 are not uncommon either), and are also very common on most motherboards anyway.

I'm no motherboard engineer but it seems to me that the nVidia nForce 2 motherboards with onboard GeForce 4 graphics don't work this way. It uses the systembus for graphics and uses separate memory controllers for the graphics subsystem and the CPU which both can use the bus at the same time. They're also not limited to 16Mb graphics memory. My AOpen board lets me set the amount of memory to reserve for graphics in the BIOS. The default setting is 64MB, but I can set it to 128Mb at least. I only have 256Mb in that machine, so I can't go higher because there would be no system memory left so I don't know what the actual upper limit is, if there is one.

[Casper]

@neko
Thank you for your insightful answers,  you seem to know your motherboard electronics. =)

As it stands, anyway, you can't get around the fact that you don't need AGP faster than 1x with a decent graphics card. With an 8MB Permedia card, you're going to be in trouble. With a Radeon 8500 at 64MB average memory, you won't.

Well, the whole thing is largely academic anyway, since MorphOS (or any of the other OSes is supports) in the foreseeable future  is unlikely to get any games that are at such a level where this could be an issue anyway. It took Valve more than 5 years to create Half-Life 2, so well probably see Pegasos III, IV and V before such a game would become available for MorpOS.