3DLabs/TI Permedia2 overclocking

Here's two messages I got from Permedia2 owners. One message gives directions for overclocking under Windows95, and the other gives directions for overclocking under Windows NT4.

As usual, I urge *caution* before twiddling with the system registry! MAKE A BACKUP OF YOUR REGISTRY BEFORE PROCEEDING!!! Then *Carefully* follow the directions below:

Windows 95 overclocking

Here is some info on overclocking the Permedia2. I have actually not done
it yet. To tell you the truth it's working fine as it is. I'm using it
for 3DStudioMax and it works pretty well. Well here it is...

Do a registry search for a key called "systemclock". This is a hexadecimal number representing clockspeed. Some Permedia2 driver installs create this key, some do not. Those that do not, will show your clock rate in system device manager as being 80mhz. Most Permedia boards are at least clocked at 83. Without a heat-sink on the chip, and with standard 10ns SGRAM, 96mhz is about as high as you can go. With a heat sink, and 8ns SGRAM (no boards currently shipping have 8ns that I know of, although Hercules's 3D/GL is supposed to have 8ns) you can go to as high as 125. Your mileage may vary. if you do not have the systemclock key in your registry, you can add it... go to....

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Display\000x\Default
the "000x" could be "0000", "0001", or "0002" depending on how many adapters you've installed without doing a clean windows install. You should be able to look in the different "DEFAULT" keys, and figure which is for your current Permedia driver install. Add a binary key called "systemclock" then modify it. Remember it's a hexadecimal number, so, for instance, "5a" would be 90, "60" would be 96, etc...
Warning! If you do go too high, and the system hangs, boot in safe mode, edit the registry key, and reboot. the chip itself is pretty stable with adequate cooling to some pretty high clocks (as I said above, up to 125 theoretical, with the right fan), so it's unlikely you'd damage the chip unless you get crazy with your clock values. On a 10ns board, you'll be running into bandwidth problems at 96mhz or so........

Victor

Windows NT4 (SP3) overclocking

-----------------------------------
Newsgroups: comp.sys.ibm.pc.hardware.video
Subject: Overclocking Permedia2
Date: 7 Dec 1997 00:50:02 GMT
Organization: EuroNet Internet
Message-ID: <01bd02aa$93a21210$10c24ac3@leporello>
NNTP-Posting-Host: i012.bru.euronet.be
X-Newsreader: Microsoft Internet News 4.70.1155
Lines: 11

Has anybody else experienced that ? I owe a Diamond FireGL1000 Pro, and under NT4.0 SP3, altered the registry key HKEY_LOCAL_MACHINE-SYSTEM-CurrentControlSet-Services-Glint-Device0-PermediaC lockSpeed, and set it to 90 decimal. Went back to 83 decimal though, as the gain looked marginal (11 to 12 fps in QuakeII test, everything on, timerefresh at 1024*768 res., yes, not that many cards can have this res. in 3D).
I didn't even have to reboot to do that, clicking on test in display properties/settings after registry modification was enough. I suppose it could damage the chip, so have to be cautious.

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