@iggy

I believe you mean PCIe. And I wouldn't bother using the GbE on the SB when the SoC has two RGMII interfaces of basically the same type as the P5020.

The cost of a newer SB is a little bit of a deterrent to me, the SB600 is CHEAP. Cheap+already supported triumphs over awesome with me in this case

Note that I would _prefer_ 850, but I struggle justifying the extra expense.

_________________
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.

@olegil

SATA3 would be my primary interest with the SB850.
Although the other features are nice.

And the real added cost for either is the likely increase in complexity.

Without a Southbridge the board should only be about seven layers.

With either, probably more like twelve.

BTW I did mean PCI (the Southbridge could provide both PCI and PCI-e) and using the Southbridge LAN connection would work across multiple CPUs.

Last edited by iggy on 09-Nov-2015 at 07:43 PM.

@iggy

And Olegil will roll his eyes at me if I say A75 or A70m (my own personal preference). Why do I prefer those to sb850? USB3... Yes, more complexity. I would be surprised if AMD makes drastic changes to common peripheral types since sb600, other than adding new ones.

I think that the adantage to using Freescale RGMII for ethernet is that you can reasonably expect that to be the same RGMII peripheral across several Freescale CPUs. If you use the southbridge one, then we have the advantage that if AmigaOS changes to ARM or x86/x64, then we have more chance of reusing driver there. Or even reusing it on a different brand PowerPC CPU that does not use Freescale's RGMII peripheral, such as to use it with a sam460ex board in a PCIe slot of that motherboard.


SOUTHBRIDGE SB600 (min qty 1)
RoHS compliant
1-$14.7547
10-$11.5378
50-$10.9332
100-$10.6850
500-$10.4064
1,000+-$10.2419


SOUTHBRIDGE SB850 (min qty 500)
500-$15.0000
2,500-$14.0000
5,000+-$13.1250


A75 Fusion Controller Hub (min qty 400)
400-$27.1400
1,201-$26.3900
2,401+-$25.6800


So my preference is expensive. The sb850 is modestly more expensive than sb600. And the sb600 is easy to buy in small numbers.

OK, "modestly more expensive" is 50% higher cost for the part alone, but that's US$5 at qty 500. Not extreme IMHO. And at qty 400-500 range, the A75 is a US$17 difference. A much bigger percentage increase, but not a rediculous number of dollars for the part alone. (Yes, there are testing and whatever other hidden costs as well)

But I don't consider the range in pricing here to be extreme. If you want a low-price A1200 class thing (not necessarily inside a keyboard type though) with an e6500, then maybe sb600 will get you the cheapest the easiest.


If you would leave off the southbridge, then I'd consider a PCIe addin card, of the southbridge, to be a good option. So anything attached to SERDES that might be used for other things, it would be convenient to bring them out to PCIe slots with small adapters to SATA plugs or whatever, which can then be removed to fit the southbridge addin card in its place, and use that southbridge's equivalent instead of the CPU's equivalent. So take out the CPU SATA adapter widget, plug in southbridge card, stop usign CPU SATA entirely and use that SERDES as PCIe instead, and start using Southbridge SATA instead. This could get you the cheapest motherbaord, while retaining the southbridge option for a lot more features in one PCIe slot.

Last edited by billt on 09-Nov-2015 at 09:36 PM.

_________________
All glory to the Hypnotoad!

@olegil

If where do an Amiga, do it modules, I think almost like the Freescale tower, just flat instead of tower, so might fit into laptop, or a tower, whatever. So you have CPU module, Power Module, Audio module and so on, this cut price on upgrading the computer, as don't need to replace everything. That way one can make CPU module with a expensive CPU without doing a BIG PCB that costs $$$$. This also means you do upgrades in increments.

Last edited by NutsAboutAmiga on 09-Nov-2015 at 10:17 PM.

_________________
http://lifeofliveforit.blogspot.no/
Facebook::LiveForIt Software for AmigaOS

@iggy

Quote:

iggy wrote: @olegil SATA3 would be my primary interest with the SB850. Although the other features are nice. And the real added cost for either is the likely increase in complexity. Without a Southbridge the board should only be about seven layers. With either, probably more like twelve. BTW I did mean PCI (the Southbridge could provide both PCI and PCI-e) and using the Southbridge LAN connection would work across multiple CPUs.

Only 7 layers without Southbridge? YAY! That's meaning a really cheap motherboard... Let's continue without it!

_________________
"When the Amiga came out, everyone [at Apple] was scared as hell." (J.L. Gassée, former CEO of Apple France and chief of devs of Mac II-fx, interviewed by Amazing Computing, Nov 1996).

@Raffaele & iggy

I strongly disagree with the reasoning that SB adds layers. You cannot do a 7 layer design, it's either 6 or 8. I am 99.9% certain I can route both SoC and SB on 8 layers. It's not like anything overlaps, except some USB and audio signals that will cross the PCIe to GPU. Two layers for PCIe plus one or two for USB/audio still leaves 4-5 layers for ground and power, which is plenty in that area.

Look at the pdf I linked again, it really is that simple. It could be even simpler by routing USB/Audio AROUND the PCIe port, if it actually looks like 6 layers is within reach.

But for 6 layers I would need microvias under the BGAs, which are not that cheap.

@a75-maniac
I totally see the reasoning behind both SATA3 and USB3, where I started rolling my eyes is your sad insistence that you need a PCIe SDXC-controller on top of this, because SDHC isn't enough for you.

_________________
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.

@billt

Btw, avnet has 16 A75 units in stock for $20 a piece, I suggest you buy a couple and make that plugin card. It would be totally awesome to have A75 support in AmigaOS.

And it's just not feasible to design a motherboard around it until it's been tested as a plugin card.

_________________
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.

@Raffaele

Quote:

Only 7 layers without Southbridge?

That was what it looked like to me.
We will see.

@

Southbridge on a card.

Sounds interesting. Also replaceable.
Would that be x1 slot? x4? x8?

_________________
Tinkering with computers.

@Signal

The most lanes that these use is x4 to cpu. Then check their ref manuals for what other configuration are possible, such as x1 or x2. Some can do x1 or x2 as well as x4 to cpu, but I don't know if all models support all lane numbers.

Last edited by billt on 10-Nov-2015 at 01:53 PM.

_________________
All glory to the Hypnotoad!

@olegil

Quote:

olegil wrote: @billt Btw, avnet has 16 A75 units in stock for $20 a piece, I suggest you buy a couple and make that plugin card. It would be totally awesome to have A75 support in AmigaOS. And it's just not feasible to design a motherboard around it until it's been tested as a plugin card.

I have a couple somewhere. (All that is in a box somewhere since we moved) tempting to get a few more when I can... I have one or two sb850 I think, and an sb600 in my box o' stuff.

_________________
All glory to the Hypnotoad!

@Signal

Southbridge on a card.

Not quite.
The A75 is a hub that is used in desktop and mobile applications.
Unlike a Northbridge/Southbridge pair, it is a single chip.

The reason we only need a Southbridge is that we are using an Soc that has most of the other functionality built into it.

I favored the SB850 over the SB600 was its feature set.

But the SB600 most closely resembles the old Southbridge components that were not AMD, Intel, or third party specific (like those made by ULi).

I haven't even looked at hubs, and documentation above the SB850 is scarce.

@olegil

Quote:

@a75-maniac I totally see the reasoning behind both SATA3 and USB3, where I started rolling my eyes is your sad insistence that you need a PCIe SDXC-controller on top of this, because SDHC isn't enough for you.

I think that was for me... :)

And I'd set that aside for the time being as two candidate sdxc controllers had vanished in that time (Jmicron then Panasonic) and Ricoh had said no (and I think theirs is eol now too). That said, SD cards continue to get bigger and bigger. I'm more interested in being able to read capacities larger than sdhc than in more speeds. And I believe we have an exfat filesystem now, if I remember correctly. If the soc's sdhc can't read my cameras card, then no, it's not good enough... my phone has 128GB uSD and they even have bigger uSD now, and regular SD cards are more capacity than that. But again, sdxc has been on back burner for a while now.

Last edited by billt on 10-Nov-2015 at 02:16 PM.

_________________
All glory to the Hypnotoad!

@iggy

Quote:

documentation above the SB850 is scarce.

I had understood the sb9x0 to be exactly the same thing as the sb8x0 counterpart, just with finer pcb design rules. That was the Internet forum conclusion I was able to find at the time I tried researching it.

Docs, and lots of them (NOT scarce), for a55, a75, a70m and one or two others are on amd's embedded developer website, there called fusion hub controllers instead of southbridge, but that is a minor distinction, and seems more marketing difference than anything else. The site requires an NDA, but that is reasonably easy to do there for these parts.

I got an AMD Gizmo 2 and a couple Gizmo 1 kits, to get an AMD jtag probe (part of the Gizmo 1 kit) to be able to learn about how the fcu on one is programmed. The gizmo 2 is an soc without an fcu, but I expect they'd reuse the sb/fcu peripherals there too for probing and learning.

But as Olegil suggests, it should be proven as adding cars first, though I would be surprised If the cpu connection has changed for the worse. The sb600/sb700/sb8x0 connection is essentially pciex4. The fcu looms like pciex4 plus graphics connections to apu cpu. So ignore the gfx part or maybe connect that to a graphics chip if on board like MicroA1 or laptop, if that would be beneficial. But I expect to find the pciex4 part not fundamentally different than sb600 to break the idea, once I or someone actually builds something to find out.

Last edited by billt on 10-Nov-2015 at 02:24 PM.

_________________
All glory to the Hypnotoad!

@iggy

Quote:

iggy wrote: But the SB600 most closely resembles the old Southbridge components that were not AMD, Intel, or third party specific (like those made by ULi).

I'm not into board design like you guys but wouldn't the SB600 32bit transfers negate any 64bit DMA? That is if 64bit DMA were to be a function wanted.

_________________
Tinkering with computers.

@Signal

Yes, but this is how it works in all boards it's ever been designed into so far, and aside from a few mishaps where it's been identifying itself as 64b capable it's working fine. I presume a 64b aware AmigaOS4+ would need some sort of "allocate 32b memory" for other PCI devices anyway, so I don't see the problem.

_________________
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.

@olegil

Cool.

_________________
Tinkering with computers.

@Ole-Egil and iggy:

I think you should both exchange your respective motherboards designs in order to check if there are too many differencies or perhaps find some useful compatibilities, or elegant design solutions for connecting electronic parts...

In these days I discussed with Iggy and from my point of view if Amiga Community will be proof capable of release an open design PPC motherboard, the first model should be minimal and have lesser features as possible, in order to keep it extremely cheap for prototyping and manufacturing, in order to keep a very extreme low price at final customer.

If we succed then we could think to a 2.0 moherboard, but actually this is only a dream. let's explore if a first 1.0 motheboard could be made. First learn to walk then how to run.

About Onboard TF-SHDC-SXDC Card Readers:

IMHO I believe that a SHDC reader onboard is useless as long a common card reader could be connected to a USB HUB in one of the USB 3 or USB 2 ports.

Lesser hardware onboard, lesser complexity, lesser layers and lesser price.

Last edited by Raffaele on 10-Nov-2015 at 04:29 PM.
Last edited by Raffaele on 10-Nov-2015 at 04:28 PM.

_________________
"When the Amiga came out, everyone [at Apple] was scared as hell." (J.L. Gassée, former CEO of Apple France and chief of devs of Mac II-fx, interviewed by Amazing Computing, Nov 1996).

@Raffaele

The sdxc thing was other discussions I've had with olegil with laptop theme, to go with SD slot in most modern laptop shells. I wouldn't consider that for a deaktop as a build-in.

_________________
All glory to the Hypnotoad!

@Raffaele

Quote:

I think you should both exchange your respective motherboards designs

Trust me, I'm PM everyone to try to group everything into a few option levels.