Asus TUF GAMING X570-PLUS M.2 ports

[asheenlevrai]

Hi everyone

 

I just bought this Asus TUF GAMING X570-PLUS board.

I am a bit puzzled since I don't know where I should install my PCIe 4.0 x4 m.2 NVMe SSD.

From what I could read, 3rd gen Ryzen CPUs have 24 PCIe lanes. 16 lanes for PCIe ports*, 4 lanes for one of the two m.2 slots and 4 lanes to communicate with the x570 chipset. Then the x570 chipset "splits" (or "forks") these 4 lanes into 16 in order to connect to everything else from USB ports, audio chip, etc...

 

It seems like the top m.2 port (the one without a heatsink) is the one m.2 port directly connected to the CPU while the bottom m.2 port (covered with a heatsink) is connected to the chipset. Please correct me if I'm wrong.

 

Now, performance-wise it would be better to plug my NVMe SSD into the m.2 slot that's directly connected to the CPU since the m.2 slot that's connected to the x570 chipset would share bandwith with other components, but at the same time, the lack of a heatsink on the top m.2 slot will probably induce throttling of the NVMe SSD under heavy load.

 

What is the best alternative? Should I use the top m.2 slot and purchase a 3rd-party heatsink for my NVMe SSD?

 

Thank you very much in advance for your help.

Best,
-a-

 

* I am not sure how these 16 lanes are divided since the board has one x16 port, one x4 port and three x1 port, that sounds more like 23 lanes to me. Except if all ports cannot work at the same time...

[St. Nick]

Do you have the Corsair, Firecuda or Aorus gen 4 ssd? because the Firecuda is the only one that comes without a heat sink isn't it?

[Founders]

2 minutes ago, St. Nick said:

Do you have the Corsair, Firecuda or Aorus gen 4 ssd? because the Firecuda is the only one that comes without a heat sink isn't it?

I know there is a version of the Sabrent Rocket Gen 4 sold without a heatsink.

[SavageNeo]

8 hours ago, St. Nick said:

ecause the Firecuda is the only one that comes without a heat sink isn't it?

no, tho aorus, corsair and a-data comes with heatsink too. Sabrent rocket is the only one what does not come with heatsink

[Otto_iii]

Does manual cite both as boot drives? If so then ya, just use spooky boi close nvme and throw a heatsink on it, but sometimes even with nice modern boards it will be like nope in one slot, even when its not the one you expect, higher speed =/= boot drive. 

i keep trying to tell people Ultra M.2 isn't capable of boot on my mobo and they are all like "naaah son its fast and sheet", well ya it is, but i've already tried it and it failed, and in very small text on only 1 page of manual can one notice the slower m.2 slot has '*Boot Drive' listed and other doesn't, thats called hidden science, a realm to explore within your own city of silicon that is your motherboard 

[asheenlevrai]

10 hours ago, St. Nick said:

Do you have the Corsair, Firecuda or Aorus gen 4 ssd? because the Firecuda is the only one that comes without a heat sink isn't it?

Firecuda

[asheenlevrai]

1 hour ago, Otto_iii said:

Does manual cite both as boot drives? If so then ya, just use spooky boi close nvme and throw a heatsink on it, but sometimes even with nice modern boards it will be like nope in one slot, even when its not the one you expect, higher speed =/= boot drive. 

i keep trying to tell people Ultra M.2 isn't capable of boot on my mobo and they are all like "naaah son its fast and sheet", well ya it is, but i've already tried it and it failed, and in very small text on only 1 page of manual can one notice the slower m.2 slot has '*Boot Drive' listed and other doesn't, thats called hidden science, a realm to explore within your own city of silicon that is your motherboard 

I didn't find anything in the manual regarding restriction on what m.2 slot supports boot drives

[caldrin]

Both slots support pcie 4.0 but i think the top one is directly connected to the CPU bottom uses chipset..

BTW I have the same motherboard but have both slots populated with pcie 3.0 nvme devices.. Both run full speed without any issues.. unsure if pci 4.0 will be any different. 

[asheenlevrai]

Useful info here :

 

I guess I'll run the OS SSD without a heatsink

[gabester]

I have a Asus TUF X570-Plus Motherboard

There are two M.2 slots. One next to the CPU and the other next to the chipset with a cover on

I plan to use identical 1TB Nvme in both of those slots.  This is not a RAID setup.

I read from various forums that they will both work at its full speed while others stated the M.2 (bottom) closer to the chipset is half the speed.  Don't know why but that defeats the purpose of the M.2's.

Other option is to use the extra PCIEx_2 and get a PCIE adapter card for the M.2.

Question is:  Is there a speed difference with the adapter compared to the second M.2 slot at half the speed if they so stated.  I can't find any info about how legit if both run at full speed which should be faster than the PCIEx

Any takers on this?

[asheenlevrai]

On 1/17/2021 at 3:23 PM, gabester said:

I have a Asus TUF X570-Plus Motherboard

 

There are two M.2 slots. One next to the CPU and the other next to the chipset with a cover on

 

I plan to use identical 1TB Nvme in both of those slots.  This is not a RAID setup.

 

I read from various forums that they will both work at its full speed while others stated the M.2 (bottom) closer to the chipset is half the speed.  Don't know why but that defeats the purpose of the M.2's.

 

Other option is to use the extra PCIEx_2 and get a PCIE adapter card for the M.2.

 

Question is:  Is there a speed difference with the adapter compared to the second M.2 slot at half the speed if they so stated.  I can't find any info about how legit if both run at full speed which should be faster than the PCIEx

 

Any takers on this?

 

The M.2 slot close to the CPU has 4 PCIe 4.0 lines direct to the CPU.

The M.2 slot next to the chipset has 4 PCIe 4.0 lines to the chipset (which acts as a relay to the CPU).

 

All devices connected via PCIe to the chipset sheae bandwidth on the only 4 PCIe 4.0 lanes connecting the chipset to the CPU. Theoretically the bottom M.2 slot could operate a PCIe 4.0 NVMe drive at full speed if only NO OTHER DEVICES connected to the chipset need any bandwidth (USB ports, ...)...

 

I don't know how these theoretical speeds translate in the reel world. Maybe you could run some benchmark and report here since you will be using identical M.2 PCIe 4.0 drives.

 

Best,

-a-

[vallan16]

Did you end up getting a m.2 cooler for the m.2 connected directly to the CPU?  If yes which one as I'm running the same board with a samsung 970 evo and due to the aging graphics card is heating the nvme drive to much (+60C) on the controller reading.  As a temp solution I increased my chassis fans just to try and getting more air flow into the system.

Thanks

[Wolfman038]

On 1/19/2021 at 12:10 PM, asheenlevrai said:

 Theoretically the bottom M.2 slot could operate a PCIe 4.0 NVMe drive at full speed if only NO OTHER DEVICES connected to the chipset need any bandwidth (USB ports, ...)...

 

 

@asheenlevrai would this extend to gpus? i have an m.2 as my boot drive in the bottom slot and im having issues with game and download crashing with a new drive in the top slot and i cant figure out if im lane sharing

[asheenlevrai]

5 hours ago, Wolfman038 said:

@asheenlevrai would this extend to gpus? i have an m.2 as my boot drive in the bottom slot and im having issues with game and download crashing with a new drive in the top slot and i cant figure out if im lane sharing

AFAIUI, the TOP PCIe slot (usually used by GPUs) and the TOP M.2 slot (closest to the CPU, no heatsink) are connected directly to the CPU via PCIe 4.0 lanes.

 

Everything else (other PCIe ports, other M.2 ports, USB, sATA, ...) connects through the chipset while sharing the connection from the chipset to the CPU (this one is 4 PCIe 4.0 lanes).

 

Lane sharing thus takes place as soon as multiple devices connected downstream the chipset need to talk to the CPU at the same time and the total of these connections is greater than what the 4 PCIe 4.0 lanes can handle.

 

Best,

-a-