I imagine they have different bridges on the vga PCB?

386SX wrote on 2021-08-20, 12:59:

Hi, […]
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Hi,

I'd like to ask which was the latest mainboard/chipset having a real PCI native link without PCI-EX1 to PCI conversion? I imagine it might be something until the Pentium 4 775?
I'd like to test some bridged PCI modern video card and to see if they run faster on a native PCI bus compared to a "fake" one.

Thank

Based on the "conversion from another (serial) protocol makes it fake" logic, the last Intel chipset that had native PCI was the i440BX.

Every chipset since that has had some different protocol between northbridge and southbridge, which was then converted into PCI on the southbridge. The later ones used PCIe for that purpose, so there's absolutely no distinction between PCI on southbridge via PCIe or PCI on some other bridge chip via PCIe.

dionb wrote on 2021-08-20, 18:02:

386SX wrote on 2021-08-20, 12:59:

Hi, […]
Show full quote

Hi,

I'd like to ask which was the latest mainboard/chipset having a real PCI native link without PCI-EX1 to PCI conversion? I imagine it might be something until the Pentium 4 775?
I'd like to test some bridged PCI modern video card and to see if they run faster on a native PCI bus compared to a "fake" one.

Thank

Based on the "conversion from another (serial) protocol makes it fake" logic, the last Intel chipset that had native PCI was the i440BX.

Every chipset since that has had some different protocol between northbridge and southbridge, which was then converted into PCI on the southbridge. The later ones used PCIe for that purpose, so there's absolutely no distinction between PCI on southbridge via PCIe or PCI on some other bridge chip via PCIe.

Thanks for this opinion. The only problem came imho when another conversion is done after the initial conversion to make it serial communication "again" right after make it parallel. I mean if I use a native PCI video card or ethernet card or whatever born for PCI I suppose none would see differences (even if from what I read audio card does have some problems) but when a PCIe GPU need another bridge cause there's this PCI bus that would not be needed at first if they used a PCIe native bus, things seems to become complicated or at least as a concept. And strange thing is that this PCI bus was originally intended from the bios as a graphic card expansion when they had the PCI-EX line free.
I remember reading somewhere here in some thread the "fake" word for these bus but not that I think these should not be "real" bus, I suppose they work good anyway. In fact even my re-bridged GT610 PCI runs quite well for such weak platform.

MSI B75A-G43 (non-gaming variant) is the latest mobo that I know of that has a native PCI support (no PCIe-to-PCI bridge) and is still somewhat widely available.
Note that, many other B6/7-series mobos use bridges even though Intel's spec shows that their chipset could support native.
P45/P55 seem like better choices, if you care about overclocking and native PCI.
You can usually tell, if a mobo has native PCI by looking for any bridge chips near the PCI slots, such as ASMedia 1083/1084 or ITE IT8892E.