NVLINK with MSI B450?

[mldonkey]

Hello all. 

 

My current build has the following:

 

- MSI B450 Gaming Pro Carbon AC

- AMD RX5700XT Sapphire Blower

 

Just ordered a Zotac RTX2070S Mini. Can still cancel it. 

 

My plan is to eventually replaced the RX5700XT with a second RTX2070S Mini and then use NVLINK to aggregate both GPUs. My application is ML so I could really use the extra VRAM given by combining both.

 

I saw that the Zotac is a low end RTX2070S so I wanted to get confirmation this is a good idea. The reason I ordered the mini is that it's cheap and will be able to re-use it in a future SFF build (I'm heavily interested in finding an mATX board with 2x M.2 slots, 4 RAM slots and dual GPU capability if anyone has an idea, to execute this SFF build.)

 

Thanks all.

 

PS: MY PSU is Gigabyte 750W I calculated it should handle both GPUs fine.

[Skiiwee29]

So with the 2070s/2080/ti's its still just SLI over the NVLink connection, the RAM isnt combined. RAM is only combined with the professional cards, the Quadro's that actually use NVLink. 

[mldonkey]

Thanks for your reply. Do you believe I should keep the 5700XT in that case, still use two 2070S to combine the CUDA cores, or should I go for something else? Will the B450 still support SLI?

[Jurrunio]

ML = machine learning? You should check whether the training model or whatever that's called play extra well with Nvidia or it doesnt care then

[mldonkey]

14 minutes ago, Jurrunio said:

ML = machine learning? You should check whether the training model or whatever that's called play extra well with Nvidia or it doesnt care then

Yep I'm looking at NVIDIA specifically for CUDA.

[igormp]

2 hours ago, mldonkey said:

Just ordered a Zotac RTX2070S Mini. Can still cancel it. 

 

My plan is to eventually replaced the RX5700XT with a second RTX2070S Mini and then use NVLINK to aggregate both GPUs. My application is ML so I could really use the extra VRAM given by combining both.

Go ahead. Just be aware that you don't even need nvlink for that, it'll net you at most an extra 10% of performance if you're really sharing data between both cards. Also, you can aggregate the GPUs this way, you need to split your workload between both (tensorflow can do this automatically for you).

 

1 hour ago, Skiiwee29 said:

So with the 2070s/2080/ti's its still just SLI over the NVLink connection, the RAM isnt combined. RAM is only combined with the professional cards, the Quadro's that actually use NVLink. 

It has nvlink but it's just limited to a single brick instead of the many in Quadros and Teslas.

 

1 hour ago, Jurrunio said:

ML = machine learning? You should check whether the training model or whatever that's called play extra well with Nvidia or it doesnt care then

AMD can't into ML at all.

[-rascal-]

2 hours ago, mldonkey said:

Thanks for your reply. Do you believe I should keep the 5700XT in that case, still use two 2070S to combine the CUDA cores, or should I go for something else? Will the B450 still support SLI?

 

If you are using NVLink like SLI (as in gaming), then NO that board does not support it.

NVLink / SLI requires the PCI-E slot to run at MINIMUM X8 electrically.

 

On your B450 motherboard (and on most B450 boards), the second PCI-E slot is X4 electrically, while X16 in length.

That, and those X4 lanes are coming from the B450 chipset, NOT from the CPU itself.

 

You would need to swap the board out to a X470 or X570 based board.

Those will have two PCI-E slots that run at:

• X16 + X0, with one GPU installed
• X8 + X8, with two GPUs installed.

[Jurrunio]

16 minutes ago, igormp said:

AMD can't into ML at all.

I'm not into ML, but in theory if there is such model that only cares about double precision fp performance AMD will have the edge.

[igormp]

1 minute ago, Jurrunio said:

I'm not into ML, but in theory if there is such model that only cares about double precision fp performance AMD will have the edge.

Sure thing, but ML really doesn't care about DP. Actually, Single precision is way better because it's both faster and smaller memory-wise.

 

AMD tried to make things work with rocm, but it has awful support (navi cards not supported at all), and subpar performance (even my 2060S performs better than a radeon VII).

[mldonkey]

13 hours ago, -rascal- said:

 

If you are using NVLink like SLI (as in gaming), then NO that board does not support it.

NVLink / SLI requires the PCI-E slot to run at MINIMUM X8 electrically.

 

On your B450 motherboard (and on most B450 boards), the second PCI-E slot is X4 electrically, while X16 in length.

That, and those X4 lanes are coming from the B450 chipset, NOT from the CPU itself.

 

You would need to swap the board out to a X470 or X570 based board.

Those will have two PCI-E slots that run at:

• X16 + X0, with one GPU installed
• X8 + X8, with two GPUs installed.

Thanks for this. Do you have any suggestions for a MOBO?

- 4 RAM slots

- 2 M.2 slots 

That's pretty much all I need from a MOBO, would love it if I could find an mATX one as well...

[mldonkey]

3 minutes ago, JobinJames said:

Which CPU are you using? Take a look at the attached excel sheet to find the best board for your CPU according to it's power delivery.

AM4 Vcore VRM Ratings v1.4 (2019-11-07).xlsx 64.91 kB · 0 downloads

I have a Ryzen 7 2700 which ideally I'd like to keep. My PSU is 750W. Will take a look at that sheet thank you.

[mldonkey]

Am I right in believing that that the ASROCK X570M Pro4 will support my dual-gpu setup? 

 

If so it actually is perfect for me. Has two M.2 storage slots, supports dual GPU and 4 ram slots!

 

Edit: seems like it doesn't do8x/8x instead does 16x/4x. I think I will have trouble finding an mATX board that does 8x/8x

[-rascal-]

3 hours ago, mldonkey said:

Am I right in believing that that the ASROCK X570M Pro4 will support my dual-gpu setup? 

 

If so it actually is perfect for me. Has two M.2 storage slots, supports dual GPU and 4 ram slots!

 

Edit: seems like it doesn't do8x/8x instead does 16x/4x. I think I will have trouble finding an mATX board that does 8x/8x

 

The market for mATX x8/x8 is very rare now.

That and graphics card being basically a minimum of 2 or 2.5 slots thick (sometimes even 3), mATX with 4 expansion slot worth of space is REALLY tight.

 

Even on the Intel Z390 side...only mATX with x8/x8 is/are:

• MSi MPG Z390M Gaming Edge AC
• ASUS ROG Maximus XI Gene *nevermind*

[mldonkey]

8 minutes ago, -rascal- said:

 

The market for mATX x8/x8 is very rare now.

That and graphics card being basically a minimum of 2 or 2.5 slots thick (sometimes even 3), mATX with 4 expansion slot worth of space is REALLY tight.

 

Even on the Intel Z390 side...only mATX with x8/x8 is/are:

• MSi MPG Z390M Gaming Edge AC
• ASUS ROG Maximus XI Gene *nevermind*

Damn need to re-evaluate my build now. I'm between a dual 2070S ATX and a 2080Ti SFF. Thanks for the info!