SAM and other new hardware - missing modern graphics card slots?

[AndyFC]

I went to teh MAG bash in Coventry (brilliant event, thank you to all the organisers) a few weeks ago and one major thing struck me during a demo of OS 4 on the SAM, during a part where the presenter mentioned that a new SAM board is coming out with more PCI slots.

Why are we stuck with PCI slots and the limited array of graphics cards? Surely an AGP slot or PCI-X wouldn't be too hard to implement now, or am I missing something?

Edit: Sorry, I meant PCIe (PCI Express), just the wrong abbreviation.

[Zac67]

In case you haven't noticed: AGP is dead and PCI-X is rapidly losing life as well (don't think there ever was a single PCI-X gfx card).

PCIe is the way forward with the industry currently moving from PCIe 1.x to 2.0.

[AndyFC]

Yes, so AGP is dead, and that supersceded PCI, so surely PCi for graphics cards is dead too?

[amiga_3k]

Modern graphics cards are normally PCI-e (PCI-express). For stuff like soundcards and network cards PCI still is the norm.

[Zac67]

I was trying to point out that AGP wouldn't put you in a much better position than PCI (except for the 2nd hand market).

OTOH, a AGP to PCI adapter can be fairly simple if the firmware/chipset support such and either use single slot PCI or two (bridged) busses - but that would lower flexibility or raise costs.

PCIe is a technology that is not easily implemented in CPLD and would require substantial additional logic/codecs, so in small volume markets it's no choice, unfortunately.

Additionally, another major problem of a niche market is the availability of drivers, so supporting current hardware is not realistic anyway. When looking at price / performance trade-offs, PCI is a rather reasonable choice as long as there's any hardware available.

[Zac67]

For stuff like soundcards and network cards PCI still is the norm.

Well, the market for soundcards and NICs has grown comparatively small with virtually every sold mainboard sporting onboard components. It'll probably shift from PCI to PCIe within the next two years.

[yakumo9275]

pci slots will be around for ages, pci-e is just a superset of pci. agp is nothing but a 4x pci slot. so it shouldne bt much more hassle but agp slots limit you to ... agp cards only.. pci slots let you put in anything pci.

pci isnt going anywhere (in a world that still ships psi and rs232 connectors on mobos).

at least with pci-e its more than just gfx cards (unlike agp).

[Zac67]

AGP was something like a crutch for eliminating the then PCI bottleneck. PCI, AGP and PCIe look extremely similar from the software side, but electrically they differ largely (PCI/AGP) to completely (PCI/PCIe).
Unlike PCI, AGP is not a bus but a point-to-point interface, so it's impossible to build a simple adapter without bridge logic.

PCIe is also point-to-point, so it allows substantial upgrading of the slots (or rather ports) while still allowing full downward compatibility for older cards - this has always been a problem with PCI and obstructed faster development. PCIe is developing much faster than PCI and probably will be around even longer than its predecessor.

[CLS2086]

No documents -> no drivers..

[Floid]

The problem has been the lack of chipsets.

In a way, you could even say that AGP put bullet holes in many of the efforts to resuscitate the Amiga 199x-through-yesterday.  They took a long time to arrive and there were never a plethora of such on the market.

Now that PCIe will be the "one true bus" for a while, if PowerPC-land can survive the next few years it should be easier to design systems that don't have to come out completely obsolete.

[AndyFC]

So the main inhibitor is development cost for a PCIe bus, and there is little point developing for AGP.

Out of interest, I looked on the price comparison site kelkoo.co.uk for Graphics Cards and it cam eup with 15 PCI cards, 18 AGP and 331 PCI Express cards (Radeon 9250 for £31 from Micro Direct for anyone with OS 4.1 btw).

On the other hand I suppose that we Amigans are used to limited-availability hardware.

[Hans_]

AndyFC wrote:
Why are we stuck with PCI slots and the limited array of graphics cards? Surely an AGP slot or PCI-X wouldn't be too hard to implement now, or am I missing something?

Enough people have already said that AGP is on the way out. With the Amigaone, its 2x AGP slot means that newer AGP cards aren't supported anyway, but PCI graphics cards are.

BTW, I'm working on supporting better cards.

Hans

[billt]

The CPU chip used on SAM440 does not have PCIe built-in. Some other PowerPC chips do. If they use such a different chip on a future SAM design, then we're in luck. Otherwise they could use a bridge chip to get PCI to PCIe.

Now, the graphics cards are x16 slots, having 16 PCIe lanes. The biggest PCIe port on any SOC PowerPC CPU I know of is x8, such as Freescale's 8641d. AMCC may have one with x8, nto sure, I remember them having some x4s somewhere. Many are x4 or x1. You could still connect and use a graphics card to a smaller port, but you'd only have the performance of the x4 or x1 port it's connected to. I'm perfectly happy with that. I believe AMCC also has PCIe2 on one of their newest chips, which doubles the data rate on a single lane, so their x4 version 2 may be roughly equivalent to Freescales version 1 x8 port, but you need the graphics chip to support PCIeV2 top benefit from that, I think some do this now.

Now, the board vendor needs to decide if it's worth doing that. Do the customers that would keep them in business need or want PCIe? Or would the added cost make the board unattractive to them? The Amiga market today alone isn't going to keep them in business for very long... They may want to give us PCIe slots but cannot make a successful business of it. Or they may have something in design that we just haven't heard about yet.

You could use one of these in a PCI slot to have the equivalent of them putting it on the motherboard:
http://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=5927#details

[Comi]

 For today Amiga hardware like Sam and Mediator are, PCI is fine solution. Procesor is very slow and beter grphic have no point.. If it have point then again PCI is not problem. Problem are drivers for newest PCI grphic cards..
Like this:  http://www.sharkyextreme.com/news/article.php/3758081

http://www.albatron.com.tw/English/Product/VGA/pro_detail.asp?rlink=Specification&no=253

[dammy]

@AndyFC

What were you expecting, a multi media desktop?  :crazy:

Dammy