What is the PLL for a Dell Optiplex 790 Minitower, are there any modifed bioses for it, can it be overclocked?

[Jared_42]

I’m looking to overclock a Dell OptiPlex 790 Minitower, ive looked for pll but cant find it, is there a modified bios i can get, can I overclock period?
All answers appreciated!

 

[maestro0428]

Sorry, but you cant overclock that rig. Most Dells locked up with only few BIOS choices.

 

[william p]

There are a couple of ways to approach overclocking. Since your asking about the PLL you're obviously considering SetFSB. The PLL is located next to a metal "can" looking crystal behind the 2nd PCIe 1x slot. You'll have to get the numbers off of it yourself. The problem with this method is you can't raise the Voltage to support much of an OC. Back in LGA775 days there were VID mods.But with the Northbridge on the CPU I don't think that works any more.
The other is the unlocked CPU method. That supports the 15-2500K, and the i7-2600K cpus. If you get one of those, then Throttlestop software can control multiplier, and Voltage in Windows. Heatsinks on the VRM MOSFETS can allow more power for the overclock. Be aware that Optiplexes have a 95W CPU limit. So they're not designed to produce massive power. Cooler N764D would probably be a good choice.
http://www.ascendtech.us/dell-xps-630-cpu-heatsink-fan-n764d_i_cfncpudelln764d.aspx
But you might have to change the plug. Be sure you get the right pinout to match your old fan. You will probably be the first one to do this on that system. Here's a thread on it.
https://www.techpowerup.com/forums/threads/throttlestop-overclocking-desktop-pcs.235975/