Underclocking a PII?

[Mongoose]

I have a Dell Optiplex GXa with a PII-266. The mobo has jumpers for 233, 266, 300, and 333, all with 66 MHz FSB. I happen to have a PII-350, which uses the same core voltage as a 333 but runs on a 100 MHz FSB.

So what will happen if I drop in the 350? With the clock speed only 2/3 what the chip is rated for, won't that effectively make the 350 run like a 233? This is NOT what I was hoping for, but I don't want to hack the mobo or anything. This is my firewall/router and the 266 is plenty, but 350 would be nice if it worked.

[JaY_III]

if your MB only has 66FSB, then you most likly have an LX chipset...
may have a 75 or 83 FSB option.... but since its a dell.... the jumper has probly been removed.

So your 350 (3.5x100)
will run at 233(3.5x66)

[batboy]

Yep, what Jay said. It will work perfectly fine and will have no problem running underclocked, ASSUMING the CPU does not have a locked multiplier. I think most of those 350 CPUs do have locked multipliers. I've heard that maybe some would run at a lower multiplier but not a higher one and some were completely locked. Guess you could try it and find out for sure. However, I'd consider looking around for a cheap used motherboard that would let you run the CPU at it's full potential.