Question AGP 2x vs PCI ?

[Wing901]

I am going to build a socket 7 computer for DOS and windows 98. The motherboard integrated with Trident 9880 agp 2x video card. I want to put in a pci 8400s or 9500. Is the performance of 8400s pci better than that of 9880 agp 2x or worse?

 

[Eximo]

AGP 2x, even 1.0, should twice as fast as a typical PCI slot, but then it comes down to how much of that bandwidth the GPUs can actually use.

8400GS was available as a PCI card.
9400GT and 9500GT were also available as PCI.

These were likely a lot slower than the PCIe versions, and were certainly intended as the last gasp for AGP.

These are much newer than any of the 8x AGP Radeon 9000 cards, but putting an AGP 8x card into a 2x slot may have adverse effects.

Probably just want to look for a better board or simply try running DOS and Win98 on newer hardware.

Around that time I had DOS and Windows XP dual booting on an Athlon X2 with an 8800GTS PCIe card. Didn't have any issues running very old games on that hardware. Most Win98 class games will run just fine in compatibility mode under XP as well, perhaps a little tweaking.

Quite a few old games actually run alright in Windows 10 and 11, but there are some that flat out refuse. Though I understand many can be thrown into a glide wrapper that does a good job of getting old OpenGL/OpenCL capable games running.

 

[Wing901]

The motherboard is no agp slot. Therefore it is no way to change the agp card. It is an onboard agp card. I tried to run windows 98 on a Athlon XP 2000+ computer but frozen as a result.

 

[BFG-9000]

In general, Super Socket 7 boards had such terrible AGP implementations that cards which actually extensively used AGP features such as ATI had severe stability problems on them (as Intel never made a 100MHz FSB Socket 7 chipset). So the hot ticket at the time for them was a manufacturer that did not use any AGP features at all--3DFX. Yes, that's why a Voodoo 3 3000 PCI has exactly the same performance as the AGP version (and of course Voodoo 2 was PCI only). Unfortunately the prices of such vintage hardware is now eye-watering and I cannot believe how many of them I passed up back when they were $1.95 used.

Given how DOS and 2D Windows performance has been ignored in some more recent cards, it seems counterproductive to try selecting the latest PCI cards available, unless you are trying to get the highest DX9 performance in Windows 98 at the expense of all else, including stability. I know I invariably experienced severe problems with cards sporting PCIe-to-AGP bridge chips and don't expect PCIe-to-PCI would be any better.

 

[BFG-9000]

BTW, if you did for some reason want the fastest DX9 performance available in a 32-bit PCI card, that would be either a rare Zotac GT430 or the more common GT520/GT610 (which are the same card and ~half the resources of GT430). They lose 30-60% performance on the 133MB/s PCI bus vs. x1 PCIe 1.1 (which at 250MB/s is comparable to AGP 1x at 266MB/s):

View: https://www.youtube.com/watch?v=yNEge5r6-mg

No idea how well these would work on Super Socket 7 (which often didn't have the best PCI implementation either) or how stable the bridge chip would be. I expect plenty of timing issues from a GPU designed to operate on a port (which AGP and PCIe are) going through a bridge to a bus where it has to share and wait its turn. And of course such a configuration would never have been tested when such GPUs were new, since Super Socket 7 was already 13 years old back then. At least Fermi was the last nVidia architecture to do triangle setup entirely in hardware so the drivers shouldn't overly tax a weak CPU.

FWIW, Trident 9880 was actually decent for 640x480 gaming in OpenGL, but the company soon folded after it was released so driver bugs were never fixed and the DX6 performance was heavily dependent on AGP features your board may not have. If you can get a 8400GS or 9500GT for cheap, then performance so far outclasses the 9880 even on PCI that you could even play DX9 games in 800x600 as they are roughly comparable to Northbridge-attached integrated graphics from the later Core 2 era such as GMA X4500HD.