pcie limitation?

[GamGrime69]

How much can I use chipset lanes on a b350 board?

I have my main gpu in top slot, and an m.2 drive in the only slot of the board. I have a 1x usb 5gb card and a basic r5 240 for vga video output.

If I add a 4x pcie to m.2 card for another nvme drive, will it's performance suffer? Or will it not be an issue?

[AbydosOne]

4 minutes ago, gamagama69 said:

How much can I use chipset lanes on a b350 board?

I have my main gpu in top slot, and an m.2 drive in the only slot of the board. I have a 1x usb 5gb card and a basic r5 240 for vga video output.

If I add a 4x pcie to m.2 card for another nvme drive, will it's performance suffer? Or will it not be an issue?

Which motherboard do you have?

 

What slot is the R5 240 in? It seems by my count you have all the slots filled in a normal B350 board.

[BobVonBob]

Whether you get fewer lanes or not won't matter. Even brand new top end GPUs barely drop in performance with fewer PCIe lanes, and that one was low end when it was new almost 9 years ago. It will run just fine no matter how many PCIe lanes it has.

[YoungBlade]

B350 boards are limited to PCIe Gen 2 from the chipset, so getting an NVMe drive won't be a great idea. You're giving up half of the performance right there if it's a Gen 3 drive, and if the board drops it to two lanes because of how much you already have attached, then you're getting dangerously close to SATA speeds. If it goes to one lane, a SATA drive will actually be faster.

 

Your motherboard manual should explain how the lanes are allocated based on where you have expansion cards.

[GamGrime69]

53 minutes ago, YoungBlade said:

B350 boards are limited to PCIe Gen 2 from the chipset, so getting an NVMe drive won't be a great idea. You're giving up half of the performance right there if it's a Gen 3 drive, and if the board drops it to two lanes because of how much you already have attached, then you're getting dangerously close to SATA speeds. If it goes to one lane, a SATA drive will actually be faster.

 

Your motherboard manual should explain how the lanes are allocated based on where you have expansion cards.

Really? Is that why it seems like my usb 3.0 card is slow?

 

 

[GamGrime69]

1 hour ago, BobVonBob said:

Whether you get fewer lanes or not won't matter. Even brand new top end GPUs barely drop in performance with fewer PCIe lanes, and that one was low end when it was new almost 9 years ago. It will run just fine no matter how many PCIe lanes it has.

I know that. Still it takes up bandwith

[GamGrime69]

1 hour ago, AbydosOne said:

Which motherboard do you have?

 

What slot is the R5 240 in? It seems by my count you have all the slots filled in a normal B350 board.

b350-f gaming

 

m.2 has ssd in it

 

top slot is my 2.5 slot 3080

 

mid 16x slot would be 4x ssd adapter (would block a little 3080 airflow but probably should be fine

 

lower 1x is usb 3.0 card

 

bottom 16x is r5 240

[AbydosOne]

Just now, gamagama69 said:

b350-f gaming

Oh, excellent, I know this board forwards and backwards.

 

1 minute ago, gamagama69 said:

m.2 has ssd in it

 

top slot is my 2.5 slot 3080

 

mid 16x slot would be 4x ssd adapter (would block a little 3080 airflow but probably should be fine

 

lower 1x is usb 3.0 card

 

bottom 16x is r5 240

This arrangement will work assuming the USB card is in slot above the middle x16 slot. Otherwise, if you put it in the other two x1s, it will downgrade the bottom x4 (x16) to x2 (which may or may not matter to you).

 

I currently have GPU (x16), USB card (x1), M.2 adapter (x4 in x16), 10G NIC (x4 in x16), plus the M.2, on mine. This is pretty much the theoretic maximum for this board.

[GamGrime69]

3 minutes ago, AbydosOne said:

Oh, excellent, I know this board forwards and backwards.

 

This arrangement will work assuming the USB card is in slot above the middle x16 slot. Otherwise, if you put it in the other two x1s, it will downgrade the bottom x4 (x16) to x2 (which may or may not matter to you).

 

I currently have GPU (x16), USB card (x1), M.2 adapter (x4 in x16), 10G NIC (x4 in x16), plus the M.2, on mine. This is pretty much the theoretic maximum for this board.

 

3 minutes ago, AbydosOne said:

Oh, excellent, I know this board forwards and backwards.

 

This arrangement will work assuming the USB card is in slot above the middle x16 slot. Otherwise, if you put it in the other two x1s, it will downgrade the bottom x4 (x16) to x2 (which may or may not matter to you).

 

I currently have GPU (x16), USB card (x1), M.2 adapter (x4 in x16), 10G NIC (x4 in x16), plus the M.2, on mine. This is pretty much the theoretic maximum for this board.

So will the middle slot run at at least 4x?

Or will I have to do lane bifurcation?

 

I don't really care what the bottom slot gets, I'm just using the r5 240 because it was cheaper than a decent hdmi to analog adapter for my crt.

My middle 1x slot is unusuable, the gpu covers it up.

[AbydosOne]

3 minutes ago, gamagama69 said:

So will the middle slot run at at least 4x?

Or will I have to do lane bifurcation?

It will run at x4 (but not x8) and doesn't support bifurcation. Using this slot will drop the main slot to x8 (which isn't generally an issue with performance).

[GamGrime69]

Just now, AbydosOne said:

It will run at x4 (but not x8) and doesn't support bifurcation. Using this slot will drop the main slot to x8 (which isn't generally an issue with performance).

There's a bios setting to drop the pcie to 8x though? Is that just limiting it for no reason?

[AbydosOne]

3 minutes ago, gamagama69 said:

There's a bios setting to drop the pcie to 8x though? Is that just limiting it for no reason?

I don't recall seeing a BIOS setting for the CPU slots. I know there's one for the Auto/x4/x2 for the bottom chipset slot.

[GamGrime69]

1 hour ago, AbydosOne said:

I don't recall seeing a BIOS setting for the CPU slots. I know there's one for the Auto/x4/x2 for the bottom chipset slot.

alright I was probably wrong then

[YoungBlade]

3 hours ago, gamagama69 said:

Really? Is that why it seems like my usb 3.0 card is slow?

 

 

What are you using the USB ports for that seems slow? USB 3.0 is slower than SATA III, so if you have an external SSD, it won't achieve max speed. PCIe 2.0 x1 offers up to 500MB/s, whereas the best SATA drives can do 560MB/s, and the best USB 3.0 does is around 450MB/s. In theory, PCIe 2.0 x1 is just fast enough if you're only doing one transfer at a time.

[BobVonBob]

3 hours ago, gamagama69 said:

I know that. Still it takes up bandwith

My bad, I totally misunderstood your setup and which part you were concerned would lose performance.

 

If you have an A-Series or Athlon CPU that slot just doesn't work, but I suspect you have a Ryzen chip.

 

On Ryzen chips, that middle x16 slot is actually connected to the CPU lanes. It will drop your GPU to PCIe 3.0 x8, which seems to be about a 3-4% performance hit on a 3080, but the m.2 drive will run at full PCIe 3.0 x4.

[GamGrime69]

3 hours ago, YoungBlade said:

What are you using the USB ports for that seems slow? USB 3.0 is slower than SATA III, so if you have an external SSD, it won't achieve max speed. PCIe 2.0 x1 offers up to 500MB/s, whereas the best SATA drives can do 560MB/s, and the best USB 3.0 does is around 450MB/s. In theory, PCIe 2.0 x1 is just fast enough if you're only doing one transfer at a time.

Yeah it has caused issues if I plugged a rift base station into it, but only sometimes. I've for some reason now been fine with 2 base station on the usb 10gb ports, and the headset and 3rd base station on usb 5g ports, seems like they have a different controller. I don't really need it but I hate usb hubs.

[GamGrime69]

3 hours ago, BobVonBob said:

My bad, I totally misunderstood your setup and which part you were concerned would lose performance.

 

If you have an A-Series or Athlon CPU that slot just doesn't work, but I suspect you have a Ryzen chip.

 

On Ryzen chips, that middle x16 slot is actually connected to the CPU lanes. It will drop your GPU to PCIe 3.0 x8, which seems to be about a 3-4% performance hit on a 3080, but the m.2 drive will run at full PCIe 3.0 x4.

Yeah imagine running a 3080 with a bulldozer Athlon holy hell