@digitaldisaster

Zorro II was 3.5MBps and Zorro III was 20MBps correct? MegaBytes not Megabits.
(For example: 100 base T is 100Mbps or 12.5MBps)

Zorro III has a theoretical burst rate of 50 MegaBytes/ Second .

The other thing about performance #'s people need to remember is those #'s are typical the optimal rate. For example, if you have a video card and move from an AGP 4x slot to a AGP 8x slot you're not going to receive video that is twice as fast.

@BrianK

Correct on both counts. Everything I ahve quote regarding speed in my last couple of posts is in Megabytes per second. Also as covered in n article at tomshardwareguide AGP 8x is in no way noticably fqaster than AGP 4x on currect (at the time - Geforce FX and Radeon 9000 series) cards - I don't know how this realtes to newer cards, the chips maybe cabable of exploting the full potential of the bus. Also RAM and Processor speeds are a limiting factor, most peoples RAM can't shift data fast enough to satisfy the fast AGP 8x speeds.

@digitaldisaster

AGP 8x is only 2.1GB/sec so it isn't really all that hard for any remotely modern chipset to saturate it.

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@DrBombcrater

For an AGP 8x bus to be saturated the system has to be capable of pulling data from the main RAM and forwarding it to the AGP bus at ~2.1Gbps. in theory you can do this on PC2100 RAM (aka DDR266) but this is increadably unlikly to happen as it relies on the RAM perofrming at 100% efficiency all the time, it usually doesn't even peak at that. Also the chipset has to be forwarding the data efficiently. When you add in dropepd and corrup packets of data and the fact that other parts of the system need the RAM as well then you don't get anywhere near 2.1Gbps throughput

@digitaldisaster

You're assuming that the North Bridge only has a single 64-bit 133MHz memory channel equipped with PC2100. I don't know of any AGP 8x capable chipset that has a memory sub-system that feeble. Most currently available chipsets have significantly better specifications.

I'll take the NForce 2 Ultra 400 as an example, because it's cheap and very popular. It has a pair of independent memory controllers each with their own 200MHz 64-bit channel for use with PC3200 memory, giving 6.4GB/sec of theoretical throughput. The processor's FSB maxes out at 3.2GB/sec so there's always enough bandwidth available to satisfy the demands of the AGP bus (even factoring in real-world dram effeciency), and the seperate controllers mean it's possible for AGP-Memory transfers to be completed without interruption even when the CPU is performing heavy memory I/O.

The NF2 North Bridge also permits CPU-AGP transfers to take place concurrently with memory operations, because the DASP unit can pre-fetch data from memory into its 64Kb buffer while denied access to the CPU because of CPU-AGP activity.

Other modern systems like the Intel 845, 915 and 925 chipsets work similarly except that they implement a single 128-bit memory controller, rather than the NForce's dual 64-bit units.

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Who do you serve, and who do you trust? - Galen

@digitaldisaster

Check your pm's

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@DrBombcrater

It is always possible in theory but never in practice. The idea is stonrg but the silicon is weak. I will find this article tomorow and make some more detailed points then but it is far too alte now (1:30 in the morning!) And I have to get up early tomorow.

@BrianK

Refer to nVIDIA's Sphere benchmarks for revealing AGP2X vs AGP4X vs AGP8X performance.

With appropriate GPU card, most applications wouldn?t saturate the AGP bus. But DOOM3(with ~512MB textures at max details) may do it i.e. needs AGP textures since most mainstream card only comes with 256MB of on board memory.

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@digitaldisaster

NVIDIA?s nForce2 with dual channel features would be able to feed AGP8X (~2GB/s), since EV6?s ~3.2GB/s consumption can only use a single MC channel from a dual channel MC pool. This is ideal for bloated games (e.g. DOOM3@max texture details) that exceed the mainstream GPU's 128MB/256MB memory capacity.

A typical value-end 333FSB K7 Athlons XP/K7 Sempr0n/nForce2 based systems can feed AGP8X (2GB/s) without any difficulties.

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Quote:

digitaldisaster wrote: @DrBombcrater It is always possible in theory but never in practice. The idea is stonrg but the silicon is weak. I will find this article tomorow and make some more detailed points then but it is far too alte now (1:30 in the morning!) And I have to get up early tomorow.

Note the practical applications from the XBOX?s nforce1 variant architecture e.g.
MC0 (or MC1) for CPU operations
MC1 (or/and MC0) for IGP operations.
NVIDIA's dual 64bit memory controllers are linked via a crossbar feature.

Just do a google search for "nForce_TwinBank_Memory_Architecture_Tech_Brief.pdf" for

"The radical crossbar memory controller enables CPU and GPU to concurrently access the two 64-bit memory banks and is optimized for 64-bit CPU and GPU accesses to ensure near perfect bandwidth utilization
...
Since the high-performance CPU and GPU data types are optimized for 64-bit access, both can access the two memory banks simultaneously and independently,
fully utilizing available memory bandwidth
" - NVIDIA's marketing materials.

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If its going to have anything to do with Amiga ... You can forget nVidia.

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@The_Editor

Note that somebody mentioned AGP4X vs AGP8X, thus the use of external examples. Anyway, IF Amiga is going mainstream then it has encounter mainstream issues.

Obtaining IBM?s G5 NB(e.g. CPC925) documents would be the ideal solution...

PS; One could refer to http://www.motorola.com/mot/doc/1/1448_MotDoc.pdf for another PPC970 based solution i.e. PPC2101.

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@digitaldisaster

Quote:

Also there are no PCI-X capable graphics cards to my knowledge, I don't even know if PCI Radeons/GeForce's can do 64bit PCI, I would guess so, anyone know?

Google(TM) for ASUS branded graphic cards...

Refer to http://www.pcupgrade.co.uk/productsDisplay.asp?keywords=GeForce+FX+(+nVidia+)+
It mentions "ASUS GeForce PCX5750 PCI-X 128MB 2xDVI VO".

Also check in
http://www.dabs.com/fr/shopbybrand/GenericBrand/GenericProductInfo.htm?quicklinx=382K&family=3816
It mentions "ASUS GeForce PCX5900 PCI-X 128MB 2xDVI VIVO"

PS I do hope that these vendors didn?t get their PCI-X and PCI-E mixed up?

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@Thread

OK - so does any of that actually have any bearing on the new board proposal?

Is there a substantial price difference between, say, 8x and 4x? If no, then logically the new board should provide the fastest.

Will anyone support/release AGP 8x cards, or will they just jump straight to PCI-X? If not, then there's no point in haveing an AGP 8x slot; depending on the timescale for development, AGP may start to get phased out - so we should only use PCI-X.

Is it physically/electronically possible to get a PCI-X and AGP slot on the same motherboard? If not, which should we go for??

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@Hammer

Not that THAT would help either, that's also nVidia chips

But it seems like SOMEONE has PCI-X graphics, even if they won't support AmigaOS.

I still have to ask, why aren't you over at http://www.nforcershq.com/forum/ instead of AW.net?


Edit:
My local webshop lists these as PCI-E (not -X), you might wanna check that again. Seems they are PCI-Express.
http://www.norek.no/k/ki.asp?sku=301305&cks=PRL

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This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@Chunder

Looks like there won't be any PCI-X graphics cards, the development goes directly from AGP to PCI-E... So you need AGP for graphics.

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This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@digitaldisaster

Quote:

Unfortauntly that is not possible, you can only buy $4500 systems once you have a $6000 system, they are extra systems for if you require more than one.

Doesn't say so on their website, is this directly from the horses mouth? Maybe you should hint to them that their website needs updating in this regard

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This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@Hammer

Quote:

Hammer wrote: @digitaldisaster Quote: Also there are no PCI-X capable graphics cards to my knowledge, I don't even know if PCI Radeons/GeForce's can do 64bit PCI, I would guess so, anyone know? Google(TM) for ASUS branded graphic cards... Refer to http://www.pcupgrade.co.uk/productsDisplay.asp?keywords=GeForce+FX+(+nVidia+)+ It mentions "ASUS GeForce PCX5750 PCI-X 128MB 2xDVI VO". Also check in http://www.dabs.com/fr/shopbybrand/GenericBrand/GenericProductInfo.htm?quicklinx=382K&family=3816 It mentions "ASUS GeForce PCX5900 PCI-X 128MB 2xDVI VIVO" PS I do hope that these vendors didn?t get their PCI-X and PCI-E mixed up?

Check out www.asus.com it lists the PCX5900 as a PCI-Express card. Quote from Nvidia website Quote:

Check out the New PCI-Express Cards: ASUS Radeon X600, X300 Series from ATI and GeForce PCX 5900, 5750 Series from NVIDIA

Here's the webpage for the board you referenced http://usa.asus.com/products/vga/en5900/overview.htm and another quote from the offical Nvidia page
Quote:

PCI-Express Interface support Delivering over 4GB per second in both upstream and downstream data transfers.

PCI-X is not PCI-Express though many confuse them. It appears that your quoted vendor may have.

@BrianK

Quote:

PCI-X is not PCI-Express though many confuse them. It appears that your quoted vendor may have.

Indeed they have confused them...

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@olegil

Quote:

I still have to ask, why aren't you over at http://www.nforcershq.com/forum/ instead of AW.net?

Already signed up to nforcershq many months ago(can't recall) i.e. usually lurking around in ASUS and Gigabyte topics.

As for AOS; I have fully restored my Amiga3000?s AmigaOS/Work setup on WinUAE-JIT. Atm, (if I have spare time) switching to PNG icons, looking/updating GUI skins and applying other updates. I do keep track of AOS4 and the availability Micro-A1.

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