This is an howto to check whether your card uses 1,5V or 3,3V (AGP2x / 4x).
Perfect for testing several 3dfx Voodoo cards like the 3dfx Voodoo 5 5000 AGP4x which actually isn't AGP4x but AGP2x.

Some examples of cards that look like an universal AGP4x card but are AGP2x cards in reality:
- ATI Rage Fury Maxx - Rage 128 pro;
- Diamond Stealth III s540 Extreme;
- Diamond Viper V770, Revision A, NVidia TNT2;
- Diamond Viper II z200 Savage 2000;
- Elsa Erazor III (100 ohms);
- Hercules 3D Prophet 4500;
- Leadtek WinFast 3D S320 II, Revision A, NVidia TNT2;
- S3 Savage4 revision 3.0 or lower;
- SIS 305 32MB;
- SiS 6326;
- VideoLogic Vivid! XS (Kyro II).

Well, I wrote an howto which is listed here:

What you need to complete this practicum

- Multimeter (if you don't have one, scroll to the bottom!);
- AGP Grahpics card.

Lay down the card with the backside facing upwards. At that point you're looking at the back of the card. Set the multimeter to measure Ohm. Also known as resistance.

Picture 1: Multimeter set to Ohm. You can see the display shows '1' since the needles aren't connected to each other. This means there is no connection. To test your multimeter you can shortcut the needles on which the display should show '0'.

Put one needle of the multimeter on pin A2 of the AGP card. Pin A2 is the second pin when looking from right to the left. On 'picture 2' you can see pin A2, it's colored in red.

Picture 2: Pin A2 marked in red.

Put the other needle on the backplate of the card. On 'picture 3' you can see more details. The arrows point to contactpoints which usually are ground (GND). The backplate of the card is, as far as I know, always connected with ground (GND). If you don't have a backplate you can use the D-SUB or DVI connector.

Picture 3: the backplate of the card.

If there is no connection between pin A2 and ground (GND) the multimeter will display '1'. This means we're dealing with an AGP 3,3V card. If the multimeter shows '0' we have an AGP 1,5V card.

Cards I've tested so far :
3dfx Velocity 100 --> 1, no connection = 3,3V;
GeForce DDR --> 0, connection = 1,5V;
3dfx Voodoo 4 4500 --> 0, connection = 1,5V.

I have no multimeter, can I still do this howto?

Yes you can. Look at the second picture in which pin A2 is marked red. As you can see the connector doesn't lead to anything. It just only a connector without a wire to something onto the graphics card. If you take the 6th pin (go four pins left starting from the A2/red pin) you see a wire from the connector to somewhere on the card. These pins are actually used.

Although I think measuring is a better way to test, this will work out also :).

19 January 2009 22:35

well Well I have had these three
- Diamond Stealth III s540 Extreme;
- Diamond Viper V770, Revision A, NVidia TNT2;
- Diamond Viper II z200 Savage 2000;

and they can do AGP x4 , I received 3 jumpers with the cards, so I could put them in a AGP x4 mode via the jumpers and without the jumpers the cards ran AGP x2.

I still have the Diamond Multimedia Viper II Z200 boxed I will try and make pics of the jumpers I mean :)

This reply has been editted 1 time.

21 January 2009 19:03

I don't know about the first and third but the second one indeed had jumpers to select AGP2x/4x operation. But if I remember correctly this was only on the later revision. The Viper V770 (TNT2 Ultra) I have here can switch but the first revisions couldn't :).

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