Question PCie version and AMD chipset B350 to B450

Mir96TA

Golden Member
Oct 21, 2002
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I always thought PCie version is a protocol and it has to have matching CPU and DMI/UEFi with CPU.
With current AGESA support for B350 can take 5K series of CPU.
These CPU can support be supported after motherboard manufacturer roll out UEFI firmware with 1.2.0.6
Once B350 have that UEFI with agesa 1.2.0.6, will that mean protocol of PCIe would be 4 and may be m.b. would have extra Pci lanes if it is electronically pass to other PCie slots (m.2 Nvme)
or all that mean, you can have 5K CPU on B350 mobo ?
Any thoughts ?
 

Tech Junky

Senior member
Jan 27, 2022
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No,

PCIE versions are HW based not FW based.

PCIE versions are based on a few things from the wiring electrically to the chipset that feed into.

UEFI handles how the boot process happens .
 

Insert_Nickname

Diamond Member
May 6, 2012
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Everything below 500-series chipsets is limited to PCIe 3.0. Including the A520.

Further, the 300/400-series are limited to PCIe 2.0 from the chipset.

If you're thinking of dropping a new 5000-series into your old board, my recommendation would be to just go for it if there is support. I've just upgraded my X370 Crosshair VI from a 1700 to a 5700X. It's just a massive all-round improvement, even if you do loose PCIe 4.0.

Drop a more modest 5600 in there and you're set up for the next 2-3 years easily.
 
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Shmee

Memory and Storage, Graphics Cards
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Sep 13, 2008
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The above is not entirely true. Some boards had the option of "unofficially" supporting PCIe gen4 when a Zen 2 CPU was installed. My Gigabyte B350 board was one of them. Some of the BIOS revisions that supported Zen 2 allowed enabling PCIe gen4, though I think it was only on certain slots on certain boards. AGESA update 1.0.0.3 ABBA put an end to this though.

As for Zen 3 on your B350, I would go for it if supported. You won't get PCIe gen4 though.
 

Mir96TA

Golden Member
Oct 21, 2002
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No,

PCIE versions are HW based not FW based.

PCIE versions are based on a few things from the wiring electrically to the chipset that feed into.

UEFI handles how the boot process happens .

UEFI is also responsible of layer 1
UEFI also define mapping of the i/o and protocol.
Thus it will play role how and what protocol to use ?

PCIE physical form factor is hardwired,
1 to 5 is protocol. I just don't know what are pre requests for ? Is it just functional requirement or arbitrary requirement.


Everything below 500-series chipsets is limited to PCIe 3.0. Including the A520.

Further, the 300/400-series are limited to PCIe 2.0 from the chipset.

If you're thinking of dropping a new 5000-series into your old board, my recommendation would be to just go for it if there is support. I've just upgraded my X370 Crosshair VI from a 1700 to a 5700X. It's just a massive all-round improvement, even if you do loose PCIe 4.0.

Drop a more modest 5600 in there and you're set up for the next 2-3 years easily.
I have a Gigabyte B450 it has AGESA 1.2.0.6, it defiantly can support PCIE 4.0
and I have a MSI B350 which can do PCie 3.0.
 

Mir96TA

Golden Member
Oct 21, 2002
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If we go and look at Intel Z590 MB, it indicates it support both PCI 3 or PCI 4 depending what CPU been is used.
This tell me UEFI has to recognize what CPU is installed to map i/o and initialized the PCI protocol so it communicate higher bandwidth protocol.
This is just academic question. or
If I can wait until MSI release newer UEFI with AEGSA 1.2.0.6 I can test it, I have GPU and CPU which I can use for testing.
 

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