Best solid/cheap Cpu+Motherboard Combo with 40+ pcie lanes

[davidk29]

As the title says i am looking for pretty solid, cheap cpu+mobo combo with 40+ pcie lanes and preferably at least 4 pcie slots. The cpu is not super important, it has to be solid but nothing special. It will be used for ai(like stablediffusion) on linux, so gpu power is all i need. What are your suggestions?

 

thanks

[ImorallySourcedElectrons]

Could try to get a server or workstation from a bankruptcy sale? I've seen some nice deals pass by left and right, and if there's only a single lot and it's offline bidding, no one bothers to show up for the single server.

[SquintyG33Rs]

nothing cheap with more than 20 lanes. it's all HEDT even used it's not cheap unless you go all the way to 10yo xeons....

[Agall]

19 minutes ago, davidk29 said:

As the title says i am looking for pretty solid, cheap cpu+mobo combo with 40+ pcie lanes and preferably at least 4 pcie slots. The cpu is not super important, it has to be solid but nothing special. It will be used for ai(like stablediffusion) on linux, so gpu power is all i need. What are your suggestions?

 

thanks

x570 or x670 with proper PCIE bifrication support if you're not always using 40+ pcie lanes. There should be enough bandwidth with the right board if its PCIe 4.0/5.0 with 24+ lanes.

 

Otherwise you're looking at X399/TR4...

 

ASUS ROG Zenith Extreme Alpha X399 HEDT Gaming Motherboard AMD Threadripper 2 (TR4) EATX - Newegg.com "x16/x8/x16/x8" 3.0.

[SquintyG33Rs]

13 minutes ago, Agall said:

x570 or x670 with proper PCIE bifrication support if you're not always using 40+ pcie lanes. There should be enough bandwidth with the right board if its PCIe 4.0/5.0 with 24+ lanes.

 

Otherwise you're looking at X399/TR4...

 

ASUS ROG Zenith Extreme Alpha X399 HEDT Gaming Motherboard AMD Threadripper 2 (TR4) EATX - Newegg.com "x16/x8/x16/x8" 3.0.

yeah, I mostly agree. but usually when people want tons of lanes they want to plug in stuff like many pro capture cards. and for some reason those are still made with pcie gen 2 8x lane for 16x 4k streams. so you're completely unable to bifurcate lanes and try and take advantage of newer gen faster speeds because the card can't use that.

 

and other such examples...

 

I don't think anybody thinks HEDT is cheap....

[Radium_Angel]

x99 chinese salvage mobo with Xeon v4 CPU.

I've built several, very solid, much fun to work with.

[Agall]

1 minute ago, SquintyG33Rs said:

yeah, I mostly agree. but usually when people want tons of lanes they want to plug in stuff like many pro capture cards. and for some reason those are still made with pcie gen 2 8x lane for 16x 4k streams. so you're completely unable to bifurcate lanes and try and take advantage of newer gen faster speeds because the card can't use that.

 

and other such examples...

 

I don't think anybody thinks HEDT is cheap....

I agree, any PCIe 5.0 system should have plenty of lanes, its just whether the motherboards can support bifrication enough to drive what you're trying to drive.

[davidk29]

22 minutes ago, Agall said:

I agree, any PCIe 5.0 system should have plenty of lanes, its just whether the motherboards can support bifrication enough to drive what you're trying to drive.

So technically i could get a cheaper intel cpu? With pcie-5 capable motherboard? I haven’t looked much into pcie5 standard yet tbh

[Agall]

1 minute ago, davidk29 said:

So technically i could get a cheaper intel cpu? With pcie-5 capable motherboard? I haven’t looked much into pcie5 standard yet tbh

There's basically a 2x relationship between generations of PCIe. The more important part is the motherboard, since not every motherboard (even premium ones) support PCIe bifurcation. You'd probably need a custom chassis like a mining rig as well to get 4 PCIe devices if they're assumingly 2 slot 16x. Most GPUs don't need to run more than 4x PCIe 3.0 in terms of bandwidth.

[davidk29]

15 minutes ago, Agall said:

There's basically a 2x relationship between generations of PCIe. The more important part is the motherboard, since not every motherboard (even premium ones) support PCIe bifurcation. You'd probably need a custom chassis like a mining rig as well to get 4 PCIe devices if they're assumingly 2 slot 16x. Most GPUs don't need to run more than 4x PCIe 3.0 in terms of bandwidth.

Just happen to have one mining chassis, well i bought one just for this, they are cheap now. And it will basically fit any board(except big server boards). Not sure, i was also looking at 2011-v3 socket mobos, cpus cheap but boards are expensive. Not sure what to do 

[Agall]

11 minutes ago, davidk29 said:

Just happen to have one mining chassis, well i bought one just for this, they are cheap now. And it will basically fit any board(except big server boards). Not sure, i was also looking at 2011-v3 socket mobos, cpus cheap but boards are expensive. Not sure what to do 

The CPUs will always be cheap since guys like me throw them up on Ebay when we retire servers. Motherboards usually not since the chassis and motherboard are proprietary, to include the PSU connections and everything. So really the only re-sellable parts are the CPU and RAM.

 

I'd say an AM4 system with a motherboard that can bifurcate two lanes to get quad 16x is the play. I know Asus' ATX boards like to allow that feature.

 

ROG Crosshair VIII Dark Hero | ROG Crosshair VIII Dark Hero | Gaming Motherboards｜ROG - Republic of Gamers｜ROG USA (asus.com)

 

AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors
AMD RyzenTM 4000 G-Series / 2000 Series Processors
AMD RyzenTM 3000 G-Series / 2000 G-Series Processors
2 x PCIe 4.0 x16 (x16 or dual x8)
2 x PCIe 3.0 x16 (x16 or dual x8)
1 x PCIe 3.0 x16 (x8 mode)
AMD X570 chipset
1 x PCIe 4.0 x16
1 x PCIe 4.0 x1

 

So I'd have to look deeper into the motherboard's manual, but that 'dual x8' is generally bifurcation. That motherboard SHOULD support 4 8x with at least 3.0 bandwidth which is all you should need.

 

 

So worst case scenario, you're running that last card with a 1x, but at least 3 are directly supported in this configuration. 

[davidk29]

46 minutes ago, Agall said:

The CPUs will always be cheap since guys like me throw them up on Ebay when we retire servers. Motherboards usually not since the chassis and motherboard are proprietary, to include the PSU connections and everything. So really the only re-sellable parts are the CPU and RAM.

 

I'd say an AM4 system with a motherboard that can bifurcate two lanes to get quad 16x is the play. I know Asus' ATX boards like to allow that feature.

 

ROG Crosshair VIII Dark Hero | ROG Crosshair VIII Dark Hero | Gaming Motherboards｜ROG - Republic of Gamers｜ROG USA (asus.com)

 

AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors
AMD RyzenTM 4000 G-Series / 2000 Series Processors
AMD RyzenTM 3000 G-Series / 2000 G-Series Processors
2 x PCIe 4.0 x16 (x16 or dual x8)
2 x PCIe 3.0 x16 (x16 or dual x8)
1 x PCIe 3.0 x16 (x8 mode)
AMD X570 chipset
1 x PCIe 4.0 x16
1 x PCIe 4.0 x1

 

So I'd have to look deeper into the motherboard's manual, but that 'dual x8' is generally bifurcation. That motherboard SHOULD support 4 8x with at least 3.0 bandwidth which is all you should need.

 

 

So worst case scenario, you're running that last card with a 1x, but at least 3 are directly supported in this configuration. 

Thanks, that’s in depth. My main system is actually am4 with ryzen9 5900x and x570 as rock taichi motherboard. Does cpu play a role in pci-e bifurcation? Because i got some ryzen cpus that i could use, so id just need to get a motherboard

[Agall]

1 hour ago, davidk29 said:

Thanks, that’s in depth. My main system is actually am4 with ryzen9 5900x and x570 as rock taichi motherboard. Does cpu play a role in pci-e bifurcation? Because i got some ryzen cpus that i could use, so id just need to get a motherboard

no, it should be specific to the motherboard. Example being my previous X570 Impact VII, which didn't for some reason have bifurcation, but the strix x570 mitx did if i remember correctly.

[SquintyG33Rs]

what are you trying to do? if it's mining you don't really need lanes. you need a mining board with 30 1x slots.

[davidk29]

6 hours ago, SquintyG33Rs said:

what are you trying to do? if it's mining you don't really need lanes. you need a mining board with 30 1x slots.

Hi,

it’s not mining, i plan to use it for Ai(stable diffusion) with 3 or 4 radeon instinct mi25, flashed to wx9100(they do pretty well) especially considering the price. I would still rather go with some older xeons or maybe something on x299 platform, but those boards are quite expensive.

[davidk29]

22 hours ago, Radium_Angel said:

x99 chinese salvage mobo with Xeon v4 CPU.

I've built several, very solid, much fun to work with.

Can you explain more? Do those Chinese mobos support any intel xeons with 40 pcie lanes? What is the situation with pcie slots on the motherboard itself, are there any motherboards with 3 or 4? And whether they all do at least x8?

thanks

[Radium_Angel]

34 minutes ago, davidk29 said:

Can you explain more? Do those Chinese mobos support any intel xeons with 40 pcie lanes? What is the situation with pcie slots on the motherboard itself, are there any motherboards with 3 or 4? And whether they all do at least x8?

thanks

I've used several with v3 and v4 Xeons, AFAIK all xeons have 40 PCIe lanes.

AS to the slots, the big ATX-sized ones have multiple PCIe slots, look here as an example:

https://machinist.site/mr9dplusblack

 

you can even buy combo sets (which is how I do it)

https://www.machiniststore.com/shop/machinist-x99-mr9s-motherboard-combo-set-kit-with-intel-xeon-e5-2680-v4-cpu-and-ddr4-32gb/

 

[davidk29]

1 hour ago, Radium_Angel said:

I've used several with v3 and v4 Xeons, AFAIK all xeons have 40 PCIe lanes.

AS to the slots, the big ATX-sized ones have multiple PCIe slots, look here as an example:

https://machinist.site/mr9dplusblack

 

you can even buy combo sets (which is how I do it)

https://www.machiniststore.com/shop/machinist-x99-mr9s-motherboard-combo-set-kit-with-intel-xeon-e5-2680-v4-cpu-and-ddr4-32gb/

 

That’s pretty sweet that would work out pretty well for me. What about the bios?(like pwm fan settings) Is it any good? And cooler compatibility? Will any 2011-3 cpu cooler work? Thanks

[Radium_Angel]

2 hours ago, davidk29 said:

That’s pretty sweet that would work out pretty well for me. What about the bios?(like pwm fan settings) Is it any good? And cooler compatibility? Will any 2011-3 cpu cooler work? Thanks

Any cooler. I had to use a fan hub as the mATX board I got had one 4 pin and one 3 pin, and I had several fans.

I did drop a fan on top of the VRM heatsink (a small 20mm one) because I felt it ran a tad warm.

There is a YT channel Miyconst that reviews only chinese salvage mobos. Very helpful if you want to take a walk on the wild side

[SquintyG33Rs]

15 hours ago, davidk29 said:

Hi,

it’s not mining, i plan to use it for Ai(stable diffusion) with 3 or 4 radeon instinct mi25, flashed to wx9100(they do pretty well) especially considering the price. I would still rather go with some older xeons or maybe something on x299 platform, but those boards are quite expensive.

ok, you don't need full bandwidth for that. even if all 4 cards run at 4x link you won't lose serious performance (only really losing on dataset load time. which isn't the performance bottleneck). so even a consumer board will be fine for you. just need to have 4 slots you can use. don't sweat the rest, finding a board with good slot spacing is a pain in the ass on it's own. especially since SLI is dead.