Question Building a Mini-ITX rig, question on X570 vs. B550

[i6pwr]

I have a 5600X needing a home, so I will build this for a portable 1080P or 1440 P gaming rig, music and video storage, and lab PC for video and pic editing from Microscope recordings.

I will use a 3060 Ti and two M.2 4.0 drives, likely 990 Pro my question is, will the B550 support 4.0 on both the M.2 and GPU or just the GPU?

I know I won't saturate the 3.0 and the performance gains are small with 4.0, but knowing I could make transfers and performance improve with 4.0 then why not.

My knowledge is with the X570 I get both 4.0 speeds on both storage and GPU, and the 550 is only one?

All input appreciated.

 

[Math Geek]

Look at the specs for the specific mobo your thinking of. It'll tell you what it does and does not support. Every board is different

 

[i6pwr]

I did check all the specs, they both have one PCI-E 4.0 expansion slot, and 4 SATA 6 GB/s ports

I believe it has something to do with the number of lanes avail between the CPU,GPU, and HD, and number of 6 GB/S SATA ports avail...that's what I'm not well versed in.

 

[Math Geek]

What is the mobo your looking at?

 

[i6pwr]

What is the mobo your looking at?

The question isn't the number of PCI-E 4.0 slots/lanes, but how many can be used at once. Example, using an X570, will the CPU use the 4.0 lanes for BOTH the GPU and HD, or just one, same applies for B550, but I believe the B550 is GPU only when a 4.0 card is used.

A few examples

B550:

https://www.gigabyte.com/Motherboard/B550-AORUS-PRO-rev-10#kf


X570

https://www.gigabyte.com/Motherboard/X570SI-AORUS-PRO-AX-rev-10#kf

Or:

ROG Strix X570-I Gaming | Motherboards | ROG United States

AMD Ryzen 3000 series mini-ITX motherboard with Aura Sync, WiFi 6(802.11ax), Intel Gigabit LAN, Dual PCIe 4.0 M.2, SupremeFX and USB 3.2 Gen 2

rog.asus.com

 

[Math Geek]

EVERY mobo is different in how it uses available lanes. some top end models even add a second chip adding more lanes for use.

you have to look at an individual board's specs to see how that model lays them out.

for instance, the GB B550 board you linked has 1 m.2 slot at 4.0 x4 and a second one at 3.0 x4. this does not conflict with the first pcie slot at all. usually it's the 2nd or 3rd pcie slot that starts disabling sata ports or dropping lanes for m.2 slots.

there is no set standard and every board can be made however the manufacturer wants. you have to look as you go for what it can do.

look at the spec sheet like this one for how it is layed out

https://www.gigabyte.com/Motherboard/B550-AORUS-PRO-rev-10/sp#sp


edit: i guess i should add that overall you are on the right track. the x570 board has more lanes to work with so you can have a lot more 4.0 slots available. i have this board and it has 3 4.0 x4 m.2 slots. something you def will not see on a b550 board

https://www.gigabyte.com/Motherboard/X570S-AORUS-ELITE-AX-rev-11#kf

 

[Math Geek]

another note is that if you are looking at mini-itx, the game changes a lot. less space means a lot less room for options. i went with this b550 board for a mini build

https://pg.asrock.com/mb/AMD/B550 Phantom Gaming-ITXax/index.asp

2 m.2 slots with one being 4.0 and the other 3.0. 2 slots is not even the norm for mini boards. one slot is on the back of the mobo to fit it in here!!

 

[CelicaGT]

The question isn't the number of PCI-E 4.0 slots/lanes, but how many can be used at once. Example, using an X570, will the CPU use the 4.0 lanes for BOTH the GPU and HD, or just one, same applies for B550, but I believe the B550 is GPU only when a 4.0 card is used.

A few examples

B550:

https://www.gigabyte.com/Motherboard/B550-AORUS-PRO-rev-10#kf


X570

https://www.gigabyte.com/Motherboard/X570SI-AORUS-PRO-AX-rev-10#kf

Or:

ROG Strix X570-I Gaming | Motherboards | ROG United States

AMD Ryzen 3000 series mini-ITX motherboard with Aura Sync, WiFi 6(802.11ax), Intel Gigabit LAN, Dual PCIe 4.0 M.2, SupremeFX and USB 3.2 Gen 2

rog.asus.com

There are 20 PCIe Gen 4.0 lanes supplied from Zen 3, these are split up as 16 lanes to the PCIe X16 slot, and 4 lanes to the chipset link. There are also 4 general purpose lanes for IO, typically 4 of which are dedicated to the primary NVMe slot.

B550 chipset adds 6 more Gen 3.0 lanes to be used as the motherboard vendor decides. In addition the 4 Gen 4.0 lanes to the chipset are run at 3.0 speeds as B550 itself DOES NOT support Gen 4.0.

X570 chipset adds 8 PCIe Gen 4.0 lanes plus some general purpose lanes to be configure by the motherboard vendor (I think it's another 8). The link between the CPU and chipset is run at Gen 4.0 speeds as X570 itself DOES support Gen 4.0.

Long answer short, the GPU and the first NVMe slot will both run at Gen 4.0 speeds on both B550 and X570. If you need more IO at Gen 4.0 speeds get X570, if not, B550 is fine.

(Edit: I can't count)

 

[i6pwr]

Ok, that makes sense then. If I can use the GPU and one M.2 drive at 4.0 with the 550 that will be fine.