I have done in the past a couple of voltmods on Voodoo 5 5500 AGP cards, but these days I was wondering about modding the PCI version so I searched the web for a guide and found none, so I decided to start from scratch and share the infos when successful.
So here it goes:

http://abload.de/thumb/v5pci_voltmodousja.jpg http://abload.de/thumb/voltmod_v5pcid8s1d.jpg

If you want to a higher overclock on your Voodoo5 5500 PCI you need to increase the voltage applied to the GPUs. I warn you need good cooling and you probably should not go past 3.3V. All you need to do is solder a 10KOhm multi-turn trimmer in parallel with R123 (top right of the card). Before soldering I suggest you set the trimmer to above 9.5KOhm. Take your multimeter and place one probe on the marked measuring point (on the voltage regulator, bottom right of the card) with the other probe connected to ground. With the system running, turn the knob on the trimmer keeping watch on the read voltage until you reach the desired value. Have fun!  :P
With the pictured card with no voltmod applied I could overclock to about 180Mhz, but after modding I was able to go up to 190Mhz when the stock 6ns RAM kicked in and started trowing artifacts. 3.2V were needed to fed the GPUs to get the card stable and it got hotter than usual.

Great research Komponent !
Maybe with a better cooling more than 190Mhz is possible !
Is this your card ? :)

Yes, my card. 190+ Mhz not possible because of RAM.
I'm not into overclocking, just did it for the fun of discovering a new mod.

Update: RAM voltmod for V5 PCI
So now you have both GPU and RAM voltmod guide for Voodoo5 5500 PCI. See pictures bellow:

http://abload.de/thumb/pciv5vmod1ys3o.jpg http://abload.de/thumb/voltmod_v5pciyssx2.jpg

Voodoo4 AGP GPU voltmod:

http://abload.de/thumb/agpv4vmodt5sc9.jpg http://abload.de/thumb/agpv4voltmodf8sbz.jpg

Voodoo4 PCI GPU and RAM voltmod:

http://abload.de/thumb/pciv4vmod8ashc.jpg http://abload.de/thumb/pciv4voltmod1zsph.jpg

Maybe one day someone might find this work useful in assisting overclocking those cards...

Hi Komponent,

What a nice guide. you are crazy with your voltmod. I like it.

Continue with your great tips.

Congratulations.

Thanks

thanks for sharing this info Komponent !
As always, amazing mods :)

the next stept will be voltmod for a v56k  ::)

Thanks, lads,
:D If I had access to a 6000 it would be an easy task, though I wonder who would dare to voltmod his.  ;D
On the other side, I would have loved to mod a 6000 to 256Mb or at least to see it done... A man can dream, right?

it could become a reality :)
just need to find a 6000 owner who is willing to do this...

what about a voodoo3 voltmod or memory mod ? 32mb  ? :)

m14radu wrote on 27.10.13 at 17:11:53:

it could become a reality :) just need to find a 6000 owner who is willing to do this... what about a voodoo3 voltmod or memory mod ? 32mb  ? :)

AFAIK Avenger is limited to 16MB.
About the voltmod it has been done already, If I remember correct you need to install a potentiometer on the last two lead of the power regulator, I'll check...

Yeah, I might be wrong, but voltmods for Voodoo2, Banshee and Voodoo3 have already been done, AFAIK.
32Mb for Voodoo3 might be possible, for the PCI SGRAM model, but I do not own any such card.

Well done komponent!!!

What I would do in VRam / Vcore is look for right smd resistor value for working voltage wished. It would be more cleaned work.

V3@32Mb- same problem here I dont own a common V3 PCI SGRAM for doing the mod. I guess it will work enabled second chip via bios. Similar V4 @128Mb.

V5-6000 @256Mb MOD- It will be done very soon. Just waiting for some stuff.

Regards,
Oscar.

Hell yes! That's what I'm talking about! Finally someone has the balls to put forward a 6000.

I might have a voodoo3 pci sgram which you can use for the modding, I will check tonight and let you know.

Before end of this year we will see a V5-6000 @256Mb. I already own a dead 6k for unsolder BGA chips and follow traces for strapping.  Just I need to find some time free. Too much projects here!

komponent- do you want to go for V3 PCI @32Mb mod? If you go for this I have in mind a Banshee @32Mb. I have some idea what resistor are needed to set 16Mb with only 4 memory bank. Now looking for ELITME 4Mb 5.5ns per chip.

Regards,
Oscar

V5 6000 @256mb - a dream come true :)

osckhar wrote on 29.10.13 at 11:53:50:

komponent- do you want to go for V3 PCI @32Mb mod?

I don't have money available to buy one.  :'( Many projects I could have completed are postponed indefinitely due to lack of funds. So go for it if you want to!

Well, I do have one, I can send to you for shipping costs, maybe with the deal that I can buy it back for the modding costs + shipping if all works well?!

osckhar wrote on 29.10.13 at 11:53:50:

komponent- do you want to go for V3 PCI @32Mb mod? If you go for this I have in mind a Banshee @32Mb. I have some idea what resistor are needed to set 16Mb with only 4 memory bank. Now looking for ELITME 4Mb 5.5ns per chip. Regards, Oscar

Niether the Banshee nor V3 will use the extra ram since they only operate in 16 bit color.

...and only 256x256 texture support. So I guess if it works we won't see any performance benefit at all.

gdonovan wrote on 30.10.13 at 01:23:21:

osckhar wrote on 29.10.13 at 11:53:50: komponent- do you want to go for V3 PCI @32Mb mod? If you go for this I have in mind a Banshee @32Mb. I have some idea what resistor are needed to set 16Mb with only 4 memory bank. Now looking for ELITME 4Mb 5.5ns per chip. Regards, Oscar Niether the Banshee nor V3 will use the extra ram since they only operate in 16 bit color.

but won't the extra ram be used if the resolution is crancked up high enough? Or would it require such a resolution that it would become unplayable anyway?

Agree 99'9% this memory upgrade will not work but until we did not try, we will not know. I think card will boot up showing 32Mb on display video bios but possible not benefit performance. I want to check if card respond using high resolution.

Regards,
Oscar.

as I said, I have a card available which can be used

Not enough raw power and missing featureset (2k texture support) will kill the benefit of more memory.

But it would be nice to see the card just recognizing 32MB  :)

it will just be a POC (Proof of Concept) then, jsut cause it can or can't be done.

I'll try to do the Voodoo3 to 32Mb possibly next week. Let me see if I can borrow one card from a fellow countryman. It would be easyer and faster this way.

@komponent, I will be out at least 10 days. So, go for V3 MOD. I want to see bios screen showing 32Mb Voodoo3.  :D

Regards,
Oscar.

@Osckhar: Did you manage to find some time for unsoldering the BGA chips  on the dead 6k card ?
The V5-6000 @256Mb will be one of a kind  :)

Komponent wrote on 30.10.13 at 20:52:28:

I'll try to do the Voodoo3 to 32Mb possibly next week. Let me see if I can borrow one card from a fellow countryman. It would be easyer and faster this way.

Hi komponent,

Did you try the mod?

This weekend I got a V3-3000 pci SGRAM and I was checking the bios. I was wrong- I thought the card used resistor  strapping for enable 16Mb with only 4 sgram chips but seems the card also used the set 2 sgram chipset. So I dont think is possible to enable 32Mb easy manner. Since first should to find the right strapping for enable 16Mb with only 4 chips bank without second sgram chipset enabled and later to enable the second sgram chipset once added the extra 4 modules chip... Or perhaps I am wrong.

Regards,
Oscar.

Yes, I tried it and didn't work.  >:(

Pity to hear it and the problem is there is not a datasheet for AVENGER chip, but I guess if 3Dfx used the second sgram chipset for enable 16Mb with only 4 chips. Possibly there is not another way to do it and will not be possible to enable extra 16Mb.  :'( :'( :'(

- Oscar.

Still, the V3 card looks nice despite the unsuccessful mod:
http://abload.de/thumb/15122013yxpod.jpg