2200g PCI-e lanes

[Totally Average Gameplay]

1 hour ago, Stefan Payne said:

Well, in Total it has 16 Lanes. 4 for Chipset, another 4 IIRC for M.2 PCIe SSD.

As for the PCIe Lanes, honestly.
Don't worry too much about it. For single GPU System its mostly irrelevant. Just get whatever you feel like it. Personally I'd look for a cheap but awesome VEGA56.

Expansions

This processor has 12 PCIe lanes, 1x8 typically designated for a GPU and 4 additional lanes for storage (e.g., NVMe).

	Expansion Options
PCIe Revision: 3.0 Max Lanes: 12 Configuration: 1x8+1x4, 2x4+1x4

 

16 Lanes? In wikichip, it says 12 only?

[Stefan Payne]

20 minutes ago, Totally Average Gameplay said:

Expansions

This processor has 12 PCIe lanes, 1x8 typically designated for a GPU and 4 additional lanes for storage (e.g., NVMe).

	Expansion Options
PCIe Revision: 3.0 Max Lanes: 12 Configuration: 1x8+1x4, 2x4+1x4

 

16 Lanes? In wikichip, it says 12 only?

Yes, 16 in total because they omited the 4 Lanes for the Chipset. I did not.

In theory you could use them.

In reality not as there is no consumer Board to my knowledge that comes without a Chipset.

And yes, Ryzen comes with a couple of S-ATA (IIRC 2), USB (IIRC 4) and also has the rest you need in the CPU as well.

 

 

So 16 total

-4 for m.2 PCIe SSD

-4 for Chipset

------

= 8 for PCIe/GPU.

[ewitte]

10 hours ago, Stefan Payne said:

Well, in Total it has 16 Lanes. 4 for Chipset, another 4 IIRC for M.2 PCIe SSD.

As for the PCIe Lanes, honestly.
Don't worry too much about it. For single GPU System its mostly irrelevant. Just get whatever you feel like it. Personally I'd look for a cheap but awesome VEGA56.

 

I have a single GPU and use 28 3.0 lanes and a 2.0x4 (10Gbit ethernet).  Though if I were to drop the GPU to 8x it would be 20.

 

BTW videos for 3000 series that just started showing up show 40 lanes of PCIe 4.0 on the consumer chips!

[Fasauceome]

3 hours ago, ewitte said:

BTW videos for 3000 series that just started showing up show 40 lanes of PCIe 4.0 on the consumer chips!

Sounds fake, I would love to see these videos because damn Ryzen 3000 is getting overhyped, I expect a decent evolution of performance but this sounds like magic bullet territory.

 

Edit: It sounds like this source conflated the supposed PCIe 4.0 doubled bandwidth with doubled lanes, I don't think the CPU would be able to "convert" its lanes to 3.0 and effectively double them, but it would be fascinating if it did do that.

[Stefan Payne]

6 hours ago, ewitte said:

BTW videos for 3000 series that just started showing up show 40 lanes of PCIe 4.0 on the consumer chips!

Something to think about:
Epyc is known to have 128 PCIe Lanes, has 4 Dies.

Threadripper is known to have 64 PCIe Lanes, has 2 dies connected to the outside.

 

Conclusion: CPU has 32 PCIe Lanes!

 

How many do you have access to on AM4?

24.

 

x16 for GPU

x4 for PCIe NVMe PCie thing

x4 for Chipset

 

My guess is that its based on the claim that new EPYC can have 160 Lanes.

160/4 -> 40

So it must be true.

 

 

No its not.

Why new EPYC can have up to 160 Lanes is simple;

a) its only applyable on the Dual Socket Boards.

b) with old EPYC they used 64 Lanes to connect both CPUs.

With PCIe 4.0 you don't need the 64 lanes as the bandwith is double. So AMD decided to allow the System Manufacturers to connect the two CPUs with less lanes between CPUs so that they use only 48 Lanes between CPUs.

 

2x old EPYC has (128-64)*2 -> 128 Lanes

2x new EPYC can have (128-48)*2 -> 160 Lanes.

 

Its a missconception.

Because Ryzen is already limited by the Socket! 

So they have to do some weird shit to get more PCIe Lanes on the Socket.

You can theoretically use the Graphics parts and use that as PCIe Lanes. But that's asking for desaster, IMO...

 

 

[Stefan Payne]

3 hours ago, fasauceome said:

Edit: It sounds like this source conflated the supposed PCIe 4.0 doubled bandwidth with doubled lanes, I don't think the CPU would be able to "convert" its lanes to 3.0 and effectively double them, but it would be fascinating if it did do that.

Yeah, that's another possibility as well.

That they thought that 20 PCIe 4.0 Lanes = 40 PCIe 3.0 Lanes.

[Fasauceome]

8 minutes ago, Stefan Payne said:

Yeah, that's another possibility as well.

That they thought that 20 PCIe 4.0 Lanes = 40 PCIe 3.0 Lanes.

If they can actually bifurcate the lanes that way then it would actually allow for 40 lanes, so dual PCIe SSD and dual graphics at full bandwidth, but I don't believe that's been done yet.

[Stefan Payne]

4 minutes ago, fasauceome said:

If they can actually bifurcate the lanes that way then it would actually allow for 40 lanes, so dual PCIe SSD and dual graphics at full bandwidth, but I don't believe that's been done yet.

You need an external device between the CPU and the device, either the Chipset or some kind of Switch to do that.

Because the Problem is that the Socket that limits the available PCIe Lanes.

 

But I'm fairly certain that AMD might name the PCie4.0 enabled Socket AM4+ for exactly that reason.

Does someone have a pinout diagram for the AM4 Socket??

[Fasauceome]

9 minutes ago, Stefan Payne said:

You need an external device between the CPU and the device, either the Chipset or some kind of Switch to do that.

Because the Problem is that the Socket that limits the available PCIe Lanes.

For multi GPU boards, don't both x16 slots have full bandwidth to the CPU directly, if you use either by itself?