Overclocking The Voodoo 5500 (Full Tutorial)

[Vanilias Ronk]

I overclocked my card, with original BIOS ram made errors at 183MHz  already in 2D, with modifid doesn't, but 3DMark 2001SE freeze, at 180MHz works fine.

[bloodworm]

Vanillias ronk,
yes, the back side of the board is where the ACTUAL "heatsink" area of the VSA100 is located.  where the little holes are, is where there are many many pins from the VSA100 soldered to the board.  they are all at "ground" potential, so care should be excersised when putting a heatsink there.  this is all fromt he VSA100 datasheet. best place for a metal heatsink and fan IMO.  water cooling would be ideal.

[Vanilias Ronk]

Thanks!
There are 2 8cm Coolink fan by the card, but I'd like to place there 2 ZALMAN ZM-RHS1 frontside heatsink.

[Vanilias Ronk]

Is it possible to automate VSA-100 overclocker? It's a little bit disturbing setting up clock speed every in 1MHz steps.

[Voodoo5]

well, I personally would not do it in 1-mhz increments (far to time consuming), my first attempt would be to try 175 mhz, then 180, then 185, etc.

My personal experience with overclocking my 6 vsa-100 based cards is that its the ram that gives out before the gpu, so aftermarket heatsink fan combiations seem like overkill to me, better off to put some ram sinks on the ram and leave the gpu as is or even better remove the factory heatsink clean off the crappy gunk 3dfx used and replace with a high quality thermal paste then re-attach.

I have a 5500 pci model with Toshiba ram that will do 200mhz stock

[Vanilias Ronk]

I didn't think about testing. I changed first 183MHz, memroy errors, BIOS flash (modded), 183 again, 3DMark/system crash, 180, everything is OK.
But every time I overclock the card must click 14 times to change freq from 166 to 180.
Original AAVID cooling is crap, it's enough perhaps for Voodoo 2, but not for VSA-100 chips.

[Voodoo5]

Original AAVID cooling is crap, it's enough perhaps for Voodoo 2, but not for VSA-100 chips.

Sorry, but I have to disagree, I beleive that except for the crappy thermal compound used by 3dfx the factory set-up is sufficient. Its the ram that is the limiting factor in overclocking VSA-100 based cards, you could put a peltier cooling system on the gpu and still not get a better overclock than with the factory set-up

As always overclocking involves a small degree of risk, but if your trying to push your card to its limits ramsinks will get you higher than any type of aftermarket cooling on the gpu

[Vanilias Ronk]

Yes, but my card was extemly hot in default speed, and my system locked up sometimes in 35°C (rams were "cold").

[bloodworm]

the rams don't really get hot at these speeds, they just can't switch on and off fast enough......

[Vanilias Ronk]

My 5500 make errors already at 180MHz with ram heatsinks.

[Caravel]

You all seem to miss the point here.  The problem isn't only heat, it's mainly voltage.  You can overclock the hell out of the VSA-100 and use liquid nitrogen cooling but it will still freeze due to insufficent voltage as regards both the VPU and the SDRAM.  Around 183Mhz is the absolute max and unless you're manipulating the pllCtrl1 variable then only one VPU will be affected anyway, so you won't see any difference at all (unless you have fsaa enabled in which case the fsaa performance hit will be lessened due to the master chip's overclocked state).  Even if you do get up to 220MHz!! or something as insane as that, you won't see much of a performance difference.

The people that do this just want to be able to say "my Voodoo is faster than yours", and nothing more.  They don't see the benefit and the card won't be able to stick to that clock rate indefinitely.  They just like to know it's overclocked.

The AAVID cooling is cheap but sufficient for the Voodoo5 at 166MHz.  The problem is that the thermal transfer expoxy resin applied between the VPU top edge and the 45x45mm aluminium heatsink base was badly applied at the production stage.  It is often offcentre and running down one side of the VPU.  It also becomes brittle with age (especially if it was running overclocked for long periods) and turns brown, it is then a much less effective thermal conductor.  Which is why overheating problems occur.

The heatsink area at the rear of the VSA-100 should not be covered.  Sticking a thermal pad and heatsink on here will cause an air pocket that will trap warm air.  This is simply becasue the surface is perforated and was not designed for the application of a heatsink.  Mounting a lone fan, or nothing at all, on each of these points would be the better option.

[bloodworm]

caravel has a good point.  the ideal heatsink for the back of the VSA's would be to scrape away the conformal coating and solder a piece of metal to the perforated section (a small peice that was FLAT on the outside part so you could then marry it to a REAL heatsink like water cooling), but you would need so much heat for such a prolonged time to get it to stick, this would be dangerous for the VSA and the board.  a simple fan hovering over the area would be a good idea though.  a thin layer of artic silver may do here to, but this can squeeze out and cause other problems.  a thermal pad would never do here.

[zourui]

damn good