Question Dual GPU Motherboard

[Furman]

Hi, I'm planning to build a new computer for programming in Unity Engine + playing games in 4K. The current project looks like this:

1. PROCESSOR - I need a powerful processor, because I'm working on a very large project in Unity, the current choice fell on the 9950X3D. Very expensive, but I don't want to save money here, I just want to take what's currently on top.
2. MOTHERBOARD - this is where the problems begin, because I need 6 monitors. Yes, I know it's crazy, I simply need 4 screens for Unity + Visual Studio alone, and Git, Spotify, Chrome, Discord, Notes, ChatGPT turned on all the time. In short, for me, you can never have too many monitors (I'm currently working on 4). That's where I came up with the idea of buying a Motherboard for two GPUs to connect 6 monitors. The cheapest I found in my country is: ASUS ProArt B650-Creator. From what I've seen, even for the most powerful graphics cards, PCIe 4.0 is enough. An alternative is MSI MPG X670E Carbon WIFI , but the price increases significantly.
3. GRAPHICS CARDS - I don't have huge requirements here. I plan to switch to a 4K TV and play GTA V at 120fps, sometimes maybe something more demanding. That's why I plan to buy RX 9070 XT as the main card, and as a secondary card for these additional monitors I already have RX 5600 XT.
4. RAM - GOODRAM 64GB 6000MHz CL30 IRDM
5. SSD - Samsung 980 PRO 2TB M.2
6. CPU COOLING - Noctua NH-D15
7. POWER SUPPLY - Be Quiet! Pure Power 12M 1000W
8. CASE - Fractal Design Pop Silent / Fractal Design Pop Silent XL

And now the questions that arise in my mind regarding these two GPUs:
1. Will this work? Will the connectors of this motherboard (PCIe 4.0 x16 [electrical x16] and PCIe 4.0 x16 [electrical x8]) be enough for these GPUs?
2. If I want to play on the main card, will the fact that a second, weaker card is connected affect the performance?
3. Is ASUS ProArt B650-Creator enough or is it better to pay extra for MSI MPG X670E Carbon WIFI?
4. By the way, is Fractal Design Pop Silent enough or is it better to buy Fractal Design Pop Silent XL? What about temperatures: is it better to have a larger case and more fans or does it not matter much?

If I made a mistake somewhere or did not foresee something, I am waiting for suggestions 😉

 

[Misgar]

Will the connectors of this motherboard (PCIe 4.0 x16 [electrical x16] and PCIe 4.0 x16 [electrical x8]) be enough for these GPUs?

It's possible that both GPUs will run at x8, not x16 and x8. That might be enough for most apps, but I guess you might see a drop if FPS on some games.

I have no idea how Windows 11(?) and any games might handle more than one GPU. I do know my video rendering programs use all available GPUs, even the iGPU in my 7950X.

Check the user guide on any mobo you might buy and see what the PCIe lane allocation is with two cards installed. The X670E might have more available lanes if an additional chipset is fitted.

Check also how your programs work if they find two GPUs. Some apps might ignore the second GPU. If you have a working computer, fit a second (cheap) GPU and see if it's used (try HWMonitor and check power on each GPU).

 

[Furman]

Now I see, you are right Misgar. In ASUS ProArt B650-Creator if I connect two GPUs, both will run at PCIe 4.0 x8 and this can be a problem in some cases. If I use MSI MPG X670E Carbon WIFI both cards will run at PCI 5.0 x8 (which I assume is equivalent to PCIe 4.0 x16, which is satisfactory). So I should probably go for X670E and if I didn't miss anything it will be fine 😀

 

[QyInvoLing]

1. Will this work? Will the connectors of this motherboard (PCIe 4.0 x16 [electrical x16] and PCIe 4.0 x16 [electrical x8]) be enough for these GPUs?

4.0x8 won't be the bottlenect, as it's equal to 3.0x16, which satisfies 4090's need.

2. If I want to play on the main card, will the fact that a second, weaker card is connected affect the performance?

Just play the game on the monitor which is linked to the main card.

3. Is ASUS ProArt B650-Creator enough or is it better to pay extra for MSI MPG X670E Carbon WIFI?

It's good enough.

 

[stonecarver]

I have no idea how Windows 11(?) and any games might handle more than one GPU

Although my GTX 690 is more or less a hybrid SLI duel GPU with it and Windows 11 plus the latest drivers for the old girl it will auto default and where it can and run both GPU's in SLI just fine in Windows 11 so SLI is dead but not fully.

I have less issues with graphics with Windows 11 than Windows 10, 7, or XP.

 

[CountMike]

That CPU has an IGPU on level of GTX 1050 so it should be enough for light work on 2 monitors.