4-way crossfire on single x16 slot???!!!!! WTF

[Islam Ghunym]

I got 4 RX 580 GPUs for mining plugged them into my motherboard PCIE 2.0 x1 slots using riser boards, it ran good as intended and we all know that PCIE bandwidth does not matter for mining but for gaming it does for sure, now it came to my head that "what if I used them for gaming in 4-way crossfire for sometimes"

it will be very good experience even if they ran with limited performance gain, so I thought that I will need to split my motherboard single 3.0 x16 slot to 4 slots of 3.0 x4, I searched for an adapter for this matter but all I found are x16 to 2 x 8, x16 to 1 x4 and some crazy single x1 to 4 x16! but not what I need.

 

while searching I came across PCIE x16 3.0 to 4 M.2 NGFF adapter which for sure split the x16 slot to 4 x4 as I want, but I read that it requires "PCIe bifurcation done on the motherboard".

 

My prime H310M-D motherboard runs only in x16 mode, but as I think x16 is all lanes which means all 4 x4 should be active, not sure about that.

 

I thoink if I buy high quality M.2 NGFF to PCIE 3.0 X4 I will be able to blug the 4 RX 580 in my single X16 slot and get better performance for gaming while still able to use them for mining

 

does anyone has a better idea for me, I really need a good idea and I will be for sure glad for it

[Pixel5]

4 card being slowed down by the bandwidth wont get any better than 1 as each card will still have to get the entire set of data delivered to it so you will get massive micro stutters.

[Spotty]

4-way Crossfire support & scaling in games is either non existent or poor. Adding to that your PCIe bandwidth issues you're probably not going to have an enjoyable time.

 

If you're finished with mining then sell the 4 cards and buy a new, more powerful single card. If you're still mining then when you want to game just run a single RX580 which should still be pretty decent for 1080p gaming.

[mariushm]

Bifurcation is something that must be supported by the processor, motherboard and enabled through BIOS.

Threadripper supports it, some AM4 boards support it.

Your board considering it's using the H310 chipset, super unlikely to support it.

There are adapter boards which contain a pci-e switch (PLX/Avago/whatever) that takes the 16 lanes and creates 32 lanes (4 x 8 lanes) like a network switch, but such adapter cards are expensive (the chip alone can be up to 30-50$)

For example PEX8508 is 54$ and it's just a x8 to 5 pci-e ports (x1 to x4 each) : https://www.digikey.com/product-detail/en/broadcom-limited/PEX8508-AC25BI-G/516-3378-ND/6150775

 

For Crossfire, you really need at least pci-e x4 for each video card ... you'll have that with some x570 boards and maybe there's a x470 board somewhere which has 2 x4 slots besides 2 x16 slots.

I'm not up to date with Intel cards.

Also, not sure sure how many games actually support Crossfire with more than 2 video cards... few support Crossfire in the first place.

[Islam Ghunym]

1 hour ago, Spotty said:

4-way Crossfire support & scaling in games is either non existent or poor. Adding to that your PCIe bandwidth issues you're probably not going to have an enjoyable time.

 

If you're finished with mining then sell the 4 cards and buy a new, more powerful single card. If you're still mining then when you want to game just run a single RX580 which should still be pretty decent for 1080p gaming.

I am completely confused about how bad 4-way crossfire, poor and not even existed exactly as you descriped, but what about dual GPU at least x8 + x8 I have seen intresting benchmarks for some games like sniper elite 4 which completely had 200% performance with dual gpu, some games also suffers from stuttering, others have not been effected, but I think dual gpu still worths considering, do you have any idea how I can split that x16 to 2 x8 and will it even work?

[Islam Ghunym]

1 hour ago, mariushm said:

Bifurcation is something that must be supported by the processor, motherboard and enabled through BIOS.

Threadripper supports it, some AM4 boards support it.

Your board considering it's using the H310 chipset, super unlikely to support it.

There are adapter boards which contain a pci-e switch (PLX/Avago/whatever) that takes the 16 lanes and creates 32 lanes (4 x 8 lanes) like a network switch, but such adapter cards are expensive (the chip alone can be up to 30-50$)

For example PEX8508 is 54$ and it's just a x8 to 5 pci-e ports (x1 to x4 each) : https://www.digikey.com/product-detail/en/broadcom-limited/PEX8508-AC25BI-G/516-3378-ND/6150775

 

For Crossfire, you really need at least pci-e x4 for each video card ... you'll have that with some x570 boards and maybe there's a x470 board somewhere which has 2 x4 slots besides 2 x16 slots.

I'm not up to date with Intel cards.

Also, not sure sure how many games actually support Crossfire with more than 2 video cards... few support Crossfire in the first place.

Do you have any suggestion for me for dual setup? (PCIE x16 splitting to 2 PCIE x8 required)

[mariushm]

29 minutes ago, Islam Ghunym said:

Do you have any suggestion for me for dual setup? (PCIE x16 splitting to 2 PCIE x8 required)

Buy a better motherboard, most likely cheaper than cards/adapters...

[Islam Ghunym]

10 minutes ago, mariushm said:

Buy a better motherboard, most likely cheaper than cards/adapters...

But changing motherboard will coast around 150$, I would prefer a reliable adapter, add to that I can use adapters with any motherboard, so it won't get wssted anyway

[Spotty]

54 minutes ago, Islam Ghunym said:

Do you have any suggestion for me for dual setup? (PCIE x16 splitting to 2 PCIE x8 required)

That would work with crossfire? Not that I'm aware of.

I'm not the best person to ask about this, but I don't believe adaptors would work due to the way CrossFire cards communicate with each other through the motherboard. 

 

As suggested you'll be best off looking at a new motherboard which has crossfire support.

What CPU do you have?

[Islam Ghunym]

1 minute ago, Spotty said:

That would work with crossfire? Not that I'm aware of.

I'm not the best person to ask about this, but I don't believe adaptors would work due to the way CrossFire cards communicate with each other through the motherboard. 

 

As suggested you'll be best off looking at a new motherboard which has crossfire support.

What CPU do you have?

I7-8700

[Islam Ghunym]

5 minutes ago, Spotty said:

That would work with crossfire? Not that I'm aware of.

I'm not the best person to ask about this, but I don't believe adaptors would work due to the way CrossFire cards communicate with each other through the motherboard. 

 

As suggested you'll be best off looking at a new motherboard which has crossfire support.

What CPU do you have?

Or just forget that, crossfire does no worth changing motherbaord for it, I can buy another better GPU with the extra 150 bucks that can even give far better experience than just crossfire.