What Cpu can the Dell OptiplexG1 take?

1GHz.

There is no speed limit on ANY semi-modern board. The limits are always to which cores/bus speeds are supported. A few boards had multiplier limits, but those were rare and corrected with BIOS updates.

The thing you have to consider is rarity: The fastest large volume Slot-1 processor was 850MHz. There are 1GHz Slot-1's with 100MHz bus, but those are EXTREMELY rare and often sell for over $200.

You can only use 100MHz bus. You CAN use PC133 RAM, but only if it's low density, and only at 100MHz. Often PC133 is cheaper, and PC100 is usually just low-density PC133 that's been relabled and priced up.

A good place to find RAM is Crucial, they'll go by your system to determine what RAM best fits.

There is a 256MB module which should work and probably isn't on Crucial's list. If you need part numbers, I can provide them, but check Crucial first.

So basically any Slot-1 100MHz bus processor will work.

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