I have one of those AGP to PCI adapters. I can take some high resolutions scans and post them if that would help.

why would you ever need to adapt an AGP slot to accept a PCI card? I've never once seen a motherboard with AGP that didn't also have a PCI slot

maxtherabbit wrote on 2020-09-23, 15:51:

why would you ever need to adapt an AGP slot to accept a PCI card? I've never once seen a motherboard with AGP that didn't also have a PCI slot

He means AGP to PCI for motherboards that don't have AGP.

mothergoose729 wrote on 2020-09-23, 15:53:

maxtherabbit wrote on 2020-09-23, 15:51:

why would you ever need to adapt an AGP slot to accept a PCI card? I've never once seen a motherboard with AGP that didn't also have a PCI slot

He means AGP to PCI for motherboards that don't have AGP.

oh I get it now, he made reference to using cards on "newer platforms" which I took to mean "platforms with AGP" but I guess he really meant platforms with PCIe + PCI

You can make quite simple and cheap AGP-to-PCI adapter, but there's a caveat. More or less "modern" AGP cards will not work with installed driver and it would be a lottery with motherboards which could work with such adapter. Quite literally. It could work with one 430HX motherboard, but will refuse to work with other.

Something like this?

Even made a bracket for the V5 😀

I designed it a couple of months ago, AGP 1.0 1x (3.3V only), 4 layer board with uninterrupted ground plane under PCI signals, properly terminated unused AGP signals, 12V PCIe power input, 3.3V/5V switching power supplies which can deliver more power than the AGP specs require, separately filtered AGP VIO, high speed level shifters, it can work in any 3.3V/5V PCI slots, 33/66MHz jumper (if the mobo supports PCI 66MHz ofc), 2 fan headers with support for 5V/12V 3pin/4pin fans and adjustable PWM.

Nice. I'm pretty sure that is way fancier than the adapter I have.

Thanks! Quite possible. Most existing AGP to PCI adapters are pretty crappy, for example some have one or more of the following:
-linear regulators, which get stupidly hot
-no filtered AGP VIO, might cause instability
-no level shifters, plugging a card like a V4/5 into an older PCI slot will kill the VSA since it's not 5V tolerant. Cards like the V56K would be fine since the HiNT bridge is 5V tolerant (not that I could imagine someone plugging a V56K into such an old MB).
-unterminated AGP signals, might cause erratic behavior with some cards or they would simply not work at all
-PCI signals routed without a reference plane, and/or no length adjustments for CLK , might cause instability
-probably some other things as well

Of course there are cards that probably won't work with this adapter (I tested a bunch of 3dfx cards, some old Nvidia & Intel cards, they all worked fine), as this is just implementing the PCI part of the AGP spec, so no AGP sideband signaling support.

I also made a PCIe x4 to AGP 1.0 1x adapter with adjustable AGP clock (up to 150MHz or so), but haven't got the time to assemble it yet.

The Serpent Rider wrote on 2020-09-23, 16:08:

You can make quite simple and cheap AGP-to-PCI adapter, but there's a caveat. More or less "modern" AGP cards will not work with installed driver and it would be a lottery with motherboards which could work with such adapter. Quite literally. It could work with one 430HX motherboard, but will refuse to work with other.

You're absolutely right, but for cards that only use the AGP socket as a faster PCI slot (i.e. Voodoo cards), it'd be very handy. PCI Voodoo 3's and Banshee cards seem to be more expensive than their AGP counterparts, so being able to use AGP cards in a PCI slot instead would be very useful.

sdz wrote on 2020-09-23, 17:51:

Something like this? […]
Show full quote

Something like this?

20200624_184104.resized-1024x365.png
20200624_1841042.resized-1024x365.png

Even made a bracket for the V5 😀
20200624_183901-1024x665.jpg
20200624_183924-1024x634.jpg

I designed it a couple of months ago, AGP 1.0 1x (3.3V only), 4 layer board with uninterrupted ground plane under PCI signals, properly terminated unused AGP signals, 12V PCIe power input, 3.3V/5V switching power supplies which can deliver more power than the AGP specs require, separately filtered AGP VIO, high speed level shifters, it can work in any 3.3V/5V PCI slots, 33/66MHz jumper (if the mobo supports PCI 66MHz ofc), 2 fan headers with support for 5V/12V 3pin/4pin fans and adjustable PWM.

Fantastic! I'm not surprised that someone has already made one. I'd certainly be interested in buying one, as I'm sure many others would be on here! That bracket is super cool too. I'd really like one of these so I can use my Voodoo Banshee on my Socket 7 board, and also to try a ViRGE GX2 on there as well, as it seems that the GX2's were only ever AGP (despite not actually using any of AGP's funky features).

but for cards that only use the AGP socket as a faster PCI slot (i.e. Voodoo cards), it'd be very handy

Only if it could work on almost everything. But like I said, such adapters more often than will not boot on particular motherboard - Any VOGONs member with an AGP to PCI adapter?

Maybe sdz design with additional buffers can solve this lottery problem, but that's yet to be proved/tested. And there's also price question.

From my limited testing (a couple of motherboards, and mostly 3dfx cards) it worked just fine. If anyone if willing to properly test it (preferably from the EU, it's easier for me to ship) I can send an adapter (as in trade it for testing, I'll add a blank PCI bracket as well 😀 ). As for price, if I ever make more, it will probably be a bit more expensive than what's currently available on ebay (the BOM cost is quite high). I'll also publish the schematics/pcb/gerbers/firmware at some point, so diy is always an option.

Also tested it with a PCIe to PCI bridge, and a couple of video cards, that worked fine as well.

Ok, looks promising.

sdz wrote on 2020-09-27, 11:14:

From my limited testing (a couple of motherboards, and mostly 3dfx cards) it worked just fine. If anyone if willing to properly test it (preferably from the EU, it's easier for me to ship) I can send an adapter (as in trade it for testing, I'll add a blank PCI bracket as well 😀 ). As for price, if I ever make more, it will probably be a bit more expensive than what's currently available on ebay (the BOM cost is quite high). I'll also publish the schematics/pcb/gerbers/firmware at some point, so diy is always an option.

Also tested it with a PCIe to PCI bridge, and a couple of video cards, that worked fine as well.
20200624_184637.jpg

I'd be happy to test, I have a handful of cards which I can do so with:

- Voodoo Banshee
- Voodoo3 3000
- Matrox G400MAX
- ATi Rage Fury Maxx
- ATI Rage IIC

Can see what other cards I can find online too!

UK based if that helps 😀 I'd love to buy an adapter too, if someone else would be better to test with (larger amount of cards to).

I think is interesting for server boards with only PCI and PCI-X. Powerfull PCI and PCI-X cards are rare and expensive. at least here. But I only have one board with PCI-X so maybe the price would make it less interesting.

sdz wrote on 2020-09-27, 11:14:

From my limited testing (a couple of motherboards, and mostly 3dfx cards) it worked just fine. If anyone if willing to properly test it (preferably from the EU, it's easier for me to ship) I can send an adapter (as in trade it for testing, I'll add a blank PCI bracket as well 😀 ). As for price, if I ever make more, it will probably be a bit more expensive than what's currently available on ebay (the BOM cost is quite high). I'll also publish the schematics/pcb/gerbers/firmware at some point, so diy is always an option.

Also tested it with a PCIe to PCI bridge, and a couple of video cards, that worked fine as well.
20200624_184637.jpg

Hi SDZ,

I have a huge collection of Retro hardware.
I have more than 150 AGP cards (nearly everything from Nvidia, 3dfx, ATI, Matrox ++) and 40 M/B (Even a M/B with 66Mhz PCI-X).
I was searching for an adapter like that!
I wanted to check the compatibility and performance hit.

So I am more than willing to test your adapters and document everything.
I am also from Europe. PM me if the offer is still on.

Totally forgot about this thread, apologies to everyone.

Hello galanopu,

That sounds great! I'll drop a PM later to arrange shipping. Would you also want/be able to test PCIe -> PCI and PCIe - > AGP adapters?

Hi SDZ,

Yes, this one is very interesting to me too.
I have a good collection of PCI audio cards to test with. Some PCI VGA and Raid cards too.
PCIe -> AGP sounds also interesting. I have some W98 compatible PCIe M/Bs.

I am a new member here, I can not PM you.
Go to my profile and check my FB. This is the best way to reach me.

Wow, those adapters do look great!
I think if you ever make a batch or two for sale, there would be a lot of potential buyers (including me).
I have a nice dual CPU S370 Tualatin board that lacks AGP and therefore still lacks a proper graphics card.

I also have a wide variety of AGP cards in my collection (about 50 I guess, from very low end to quite high end, including a V5 and a Rage Fury Maxx, too), and of course many retro systems from the mid-90s to late 00s, so in case you need more testers, feel free to reach out to me. I am located in Germany.

Hey gex85!

Sadly I have only 1 AGP-PCI adapter at the moment, and it's going to galanopu.
Note that cards plugged into this adapter will work at PCI 33/66(which is usually available on server mobos) and with no AGP features, so some modern cards might not work all that great with this kind of adapter. The main goal of this adapter was to use AGP 3dfx cards in PCI systems 😀

As for batches, I might make some, if someone else is willing to organize shipping, as I'm quite busy with various stuff at the moment (like the thing in the attached pic, a huge 16 layer PCB with 8 3dfx ICs/FPGAs/bridges/64RAM ICs, etc)
Also, when I have some time, I'll upload all the design docs (sch/pcb/gerber/bom/firmware) so anyone can build these adapters.