The card is not overclocked, 96 MHz is default clock for G250. I don't know about the bug, but in general sometimes memory controllers have to do extra work when managing more memory modules, which can lead to lower supported frequencies. Though I did not see this in the 90's and never with graphics cards.

hmm, according to the wikipedia entry the core clock speed for most of the cards is 84mhz, the Millinium is stated to be 84-90 and only the G250 is listed as 96mhz. quick check of other sources also lists the core speed as 85 mhzhttp://www.vgamuseum.info/index.php/component/ ... enium-g200

unless I'm reading it wrong.

Matrox video BIOS has 'pins' that set various specs like clock speeds in different states. Some G200 cards do have slightly reduced clocks with a memory expansion. At least for GUI (2D) mode.
http://web.archive.org/web/20040110103309/htt … .pl/gbm/matrox/
Specifically
http://web.archive.org/web/20040110123631/htt … /bios.html#pins
http://web.archive.org/web/20040102184813/htt … .html#pinsfiles

G200 runs pretty hot and is likely the cause of the instability issues that were experienced back then, just slap a little fan on it and some fresh compound then you should be fine. I had a G200 agp before the fire with a 4mb module stolen off a ati card that worked pretty good.

I think the OEM G250 which is the one that's supposedly overclocked is built on a newer process then the G200 and doesn't even come with a heat sink.

soviet conscript wrote:

I think the OEM G250 which is the one that's supposedly overclocked is built on a newer process then the G200 and doesn't even come with a heat sink.

It is passive but have never owned one and don't know how hot it runs but the older G200 does need active cooling in general. I have seen some G200 cards that were backed into a brown color from overheating with faded coolers and the cards were not even used for gaming let along any demanding 3D work. Also the coil springs on the brass push pins are not very good so replacing those will give a little more pressure which helps with thermal transfer. A 40mm fan will do the trick and might allow it to run stable at 100mhz provided the vram can handle it.

I tried doing some light testing with my G200 and G250 but unfortunately it didn't work out. in DOS I got the exact game FPS in PCPBench with both cards with 8 or 16mb od ram and when I tried to run Winmark99 max in win98 it would crash with either G200 card. I was to lazy to pull out a different machine to try it on.

I ended up just taking the heatsink off the G200 and putting it on the G250 with some half decent thermal paste. The G250 is supposed to run cooler and not even need a heatsink so that should work fine.