pci express backward compatibility

[RJ]

I'm new to PCI Express.... After reading what I could find on this
topic, I am still uncertain about backward compatibility with "plain old
PCI cards", circa 2000. I understand that PCI Express 1x, 2x, 16x
refers to the number of serial "lanes" that are linked for data
transfer, on PCI Express bus. But is PCI Express 1x effectively the
same rate as older PCI spec?

I see a motherboard spec that reads as follows :
One PCI Express x1 slots (support PCI Express Bus specification v1.0a
compliant)

Four 32-bit v2.3 Master PCI bus slots (support 3.3v/5v PCI bus
interface).

Is a PCI Express 1x slot compatible with an older PCI card?
Is this v2.3 Master PCI bus slot backward compatible with an older PCI
card?

Thanks in advance.

 

[KC Computers]

I'm new to PCI Express.... After reading what I could find on this

topic, I am still uncertain about backward compatibility with "plain old
PCI cards", circa 2000. I understand that PCI Express 1x, 2x, 16x
refers to the number of serial "lanes" that are linked for data
transfer, on PCI Express bus. But is PCI Express 1x effectively the
same rate as older PCI spec?
I see a motherboard spec that reads as follows :
One PCI Express x1 slots (support PCI Express Bus specification v1.0a
compliant)
Four 32-bit v2.3 Master PCI bus slots (support 3.3v/5v PCI bus
interface).
Is a PCI Express 1x slot compatible with an older PCI card?
Is this v2.3 Master PCI bus slot backward compatible with an older PCI
card?

PCI Express slots do NOT work with regular PCI cards. The
v2.3 Master PCI slots do.

 

[DaveW]

PCI-Express 1x slots are UNRELATED to the old PCI slots. They use different
sockets and voltages and speeds.