Installing DDR in matched pairs?

[yeeha]

I have a Dell Dimension 8300 and just bought 1gig of PC3200 from Mushkin to supplement the 2 x 512MB factory chips.

The manual for the machine says:

1) I should only install RAM in matched pairs and that failure to do so will result in degraded performance.

2) Any RAM upgrades I buy should not be matched with the original factory modules even if I bought the upgrades from Dell.

3) There should always be a module in slot 1.


Right now I have the 1gig Mushkin chip in slot 1 and the 2 x 512MB factory chips in slots 3 and 4. Am I going to experience the degradation of performance the manual speaks about? If so, would buying a 2nd 1 gig chip to match the one in slot 1 improve things? Or did the manual really only mean that I shouldn't put a chip in slot 2 that is of different size than the one in slot 1 ?

Thanks in advance for any advice or information. I don't know much about this stuff, but it also seems like the information in the manual is pretty lacking.