Hmmm... looks just like a decoupling capacitor for U52. Which appears to be some kind of multiplexer wired between the SCSI controller chip and the SCSI bus, so is probably involved with sorting out SCSI ID numbers and making sure they are decoded correctly.
The chip might actually function OK without it. Decoupling capacitors are USUALLY required by components just to give stable, ripple free power supplies, to the local chip the are closest too.
So, I guess using the same or a similar value on the card, for a similar sized component, makes sense.
If you go too low with the value, the chip won't work accurately, it will stutter and cut out. But if you only have one SCSI device connected to the external drive port, the 25 pin connector, it might not matter. If you are not using the external drive port to connect devices, it might not matter at all, because the chip it supports isn't actually ever used.
Maybe, that's how I read your situation.
http://www.bboah.com/download_photos/gforce030_3_big.jpgThat should be your card.
EDIT:
These SMD capacitors nearly always ARE marked, but you need VERY good optical magnidication to read them. Check picture. The example posted is a 100uF 6V type, which is plenty big enough for a teeny chip like that. Maybe too big, 100nF should be ample.
