Do SATA drives limit PCI-E lanes on B450i?

[Deleted member 280263]

Hi,
I'm trying to help a friend out, she has a B450i PCI-E 3.0 board, it has 1 NVME slot, and 4 SATA's - currently populated with 1X NVME, and 1X SATA.

Being that it's B and not X series, would running 1 or more SATA's with current NVME, limit the GPU etc to less than PCI-E 3.0?
Or does it not matter with SATA, and instead it's only an issue with multiple NVME's, versus having say an X series motherboard?

This is way above my head, as I just use 1 NVME with my own machine, and always have.

Is the easiest way to find out, to simply check GPU-Z for what X the GPU is running at, i.e. 3.0 in this case? Then add more SATA devices, and see if it changes?
Does it make a difference whether it's a Bluray-RW drive or an SSD, as she has one of those she'd like to use alongside the SATA SSD, or does it make no difference, be it SSD or a RW drive?

Thanks

 

[SonicSW20]

It won't limit the primary PCIe x16 slot. Check the manual for the specific board for how the remaining lanes will be distributed in that scenario.

 

[Tetras]

Is the easiest way to find out, to simply check GPU-Z for what X the GPU is running at, i.e. 3.0 in this case? Then add more SATA devices, and see if it changes?

Yeah. Unfortunately, some manufacturers omit this information from the manual, leaving trial and error as your only certain option

There are spreadsheets (linked on reddit) for B450/B550 that DO list it for the majority of boards, if you can find yours included.

From memory, I don't think limiting the PCI-E primary lanes was at all common for 400/500 boards, but SATA and secondary PCIE sharing with M.2 slots was. If you only have 1 M.2, there's a good chance it won't have an issue.

 

[Deleted member 280263]

It won't limit the primary PCIe x16 slot. Check the manual for the specific board for how the remaining lanes will be distributed in that scenario.

So if the MB only has 1 PCIe slot, will it be fine still? I guess she'll just have to try it and see

Yeah. Unfortunately, some manufacturers omit this information from the manual, leaving trial and error as your only certain option

There are spreadsheets (linked on reddit) for B450/B550 that DO list it for the majority of boards, if you can find yours included.

From memory, I don't think limiting the PCI-E primary lanes was at all common for 400/500 boards, but SATA and secondary PCIE sharing with M.2 slots was. If you only have 1 M.2, there's a good chance it won't have an issue.

It only has 1 PCIe slot and 1 NVME, and 4 SATA's, I'll let her know, and tell her to just plug the Bluray burner in and run GPU-Z At least that's a simply way of finding out versus checking it with multiple programs for different things it effects, thanks

 

[Deleted member 280263]

@SonicSW20 @Tetras I passed the information onto her, and she just confirmed that with the Bluray burner plugged into another SATA port, that GPU-Z still shows the PCIe 4.0 16X @ PCIe 3.0 16X - so I'd say that's case closed

Thank you for your help

 

[JollyJamma]

@SonicSW20 @Tetras I passed the information onto her, and she just confirmed that with the Bluray burner plugged into another SATA port, that GPU-Z still shows the PCIe 4.0 16X @ PCIe 3.0 16X - so I'd say that's case closed

Thank you for your help

I do wish that motherboard manufacturers would give consumers more reliable pci-e lane options rather than just implementing the latest pci-e generation and charging more.

Tons of people populate all of the M.2 or SATA ports on their motherboard and then find out that they are now running with reduced pci-e capacity because populating the bottom port makes the main pci-e land run at half capacity.

Glad you’re sorted though.

 

[SonicSW20]

I do wish that motherboard manufacturers would give consumers more reliable pci-e lane options rather than just implementing the latest pci-e generation and charging more.

Tons of people populate all of the M.2 or SATA ports on their motherboard and then find out that they are now running with reduced pci-e capacity because populating the bottom port makes the main pci-e land run at half capacity.

Glad you’re sorted though.

AFAIK with B450's, there is no scenario where your primary PCIe slot will lose lanes with a CPU that supports 3.0 16x. You may get reduced speed or even lose the other slots (things connected to the chipset, not the CPU directly) but never the primary one.

 

[JollyJamma]

AFAIK with B450's, there is no scenario where your primary PCIe slot will lose lanes with a CPU that supports 3.0 16x. You may get reduced speed or even lose the other slots (things connected to the chipset, not the CPU directly) but never the primary one.

Sure, yes, I recall the same but I meant in general and often with X series motherboards that have a 2nd controller for devices where it's an issue.

 

[Deleted member 280263]

I do wish that motherboard manufacturers would give consumers more reliable pci-e lane options rather than just implementing the latest pci-e generation and charging more.

Tons of people populate all of the M.2 or SATA ports on their motherboard and then find out that they are now running with reduced pci-e capacity because populating the bottom port makes the main pci-e land run at half capacity.

Glad you’re sorted though.

I totally agree, it's rather ironic that it's never disclosured in general, despite having the spec for pretty much everything else? Very bizzare!

AFAIK with B450's, there is no scenario where your primary PCIe slot will lose lanes with a CPU that supports 3.0 16x. You may get reduced speed or even lose the other slots (things connected to the chipset, not the CPU directly) but never the primary one.

Sure, yes, I recall the same but I meant in general and often with X series motherboards that have a 2nd controller for devices where it's an issue.

So guys, does that mean that B550M would be the same? Or is that when stuff starts getting limited if you have multiple NVME/SATA? It's not really something I have much experience in, as I personally just run 1 NVME and leave it at that

 

[Tetras]

So guys, does that mean that B550M would be the same? Or is that when stuff starts getting limited if you have multiple NVME/SATA?

I think it started being a big issue with 1700 & AM5.

Intel 1700 CPUs (12th-14th gen) have zero spare PCI-E 5.0 lanes (all 16 are on the graphics) and zero from the chipset, so any PCI-E 5.0 M.2 slot HAS to come from the graphics lanes.

With B850/X870/X870E, the AMD CPUs usually only have 4 spare lanes left after the graphics (because 4 are used for USB4), so if the motherboard wants more than 1x PCI-E 5.0 M.2 slot, it either shares with the USB4 ports (MSI took this route, where the use of one limits or disables the other), or takes it from the graphics lanes.

There were a few B650/X670/X670E boards with primary PCI-E lane sharing (e.g. Strix B650E-E because it offers 12 lanes from the CPU for M.2 slots, which is not possible), but not so common.

Like Intel 1700, the AMD chipsets have no PCI-E 5.0 lanes.

B450/B550 were mainly just sharing between SATA/M.2 and secondary PCI-E, not the primary (graphics) lanes.

 

[Deleted member 280263]

I think it started being a big issue with 1700 & AM5.

Intel 1700 CPUs (12th-14th gen) have zero spare PCI-E 5.0 lanes (all 16 are on the graphics) and zero from the chipset, so any PCI-E 5.0 M.2 slot HAS to come from the graphics lanes.

With B850/X870/X870E, the AMD CPUs usually only have 4 spare lanes left after the graphics (because 4 are used for USB4), so if the motherboard wants more than 1x PCI-E 5.0 M.2 slot, it either shares with the USB4 ports (MSI took this route, where the use of one limits or disables the other), or takes it from the graphics lanes.

There were a few B650/X670/X670E boards with primary PCI-E lane sharing (e.g. Strix B650E-E because it offers 12 lanes from the CPU for M.2 slots, which is not possible), but not so common.

Like Intel 1700, the AMD chipsets have no PCI-E 5.0 lanes.

B450/B550 were mainly just sharing between SATA/M.2 and secondary PCI-E, not the primary (graphics) lanes.

Thanks, so in short AM5 will always limit it if you have more than one NVME, but B450/550 will let you go to town on SATA/NVME's

 

[Tetras]

Thanks, so in short AM5 will always limit it if you have more than one NVME

It will limit the primary lanes if you have more than 2x PCI-E 5.0 M.2 slots on B650(or E)/X870 (or E).

It will almost certainly limit the primary lanes if you have more than 1x PCI-E 5.0 M.2 slot on X870(or E).

In either case, if the other M.2 slots are PCI-E 4.0 and piped from the chipset instead of the CPU, then there should be lane sharing with the primary PCI-E slot.

 

[jigger]

The issue is giant video cards taking up 60% of the available space for expansion slots. There plenty of bandwidth available, it’s just render useless by the m.2 format and it’s cooling requirements. For instance, a PCIE 5 a 1x slot provides 4GB/s which is enough for a very fast M.2 drive in an add in card or 8-9 SATA drives in RAID 0.

 

[Deleted member 280263]

The issue is giant video cards taking up 60% of the available space for expansion slots. There plenty of bandwidth available, it’s just render useless by the m.2 format and it’s cooling requirements. For instance, a PCIE 5 a 1x slot provides 4GB/s which is enough for a very fast M.2 drive in an add in card or 8-9 SATA drives in RAID 0.

I hate those AM5's that now put the primary M.2 slot below the first PCI-E slot on MATX, blocking the ability to have any heatsink on the M.2, or forcing you to use the crap thin one that comes with the motherboard - which makes any M.2 you have with a built in heatsink unusable!
Also half covering the CMOS battery

This nonsense didn't exist with AM4 MATX boards, well none that I've seen.