Dell Optiplex GX 280 Small Mini Tower Processor Upgrade

You would have to get the Copper High performance heatsink or it would shut down due to overheating.

I have a suspicion that 3.2 Ghz is max and over that speed it will Halt with Incompatible processor message.

Be aware that there are 5 documented versions of the GX280, each of which has its own technical specifications, unique CPU fans, PSUs, etc. It's worth your time to be sure of the one you have and what its specs are before attempting an upgrade.
<ADMIN NOTE: Broken link has been removed from this post by Dell> 

After reading about the power consumption of the 3,8Ghz 570J, Dell's tech docs indicate that a 305W PSU is standard equipment in the Small Mini Tower (SMT) for processors running faster than 3.2Ghz.

BIOS to A08  GX280A08.EXE should be installed BEFORE attempting to install a newer processor.

I would recommend an Dimension 8400 350W Dell-branded PSU

You should check

http://processorfinder.intel.com/Default.aspx

What is the S Spec of the current cpu?

What is the S SPec of the other CPU?

What is the CPUID of the current cpu?

What is the CPUID of the other cpu?

There is no psychic reading of microcode that goes on here. What do the latest bios release notes say?

What does intel say about the chipset and fsb and packaging?

If you don't know this information its likely you don't have an idea how to handle the processors either and or will damage the motherboard and the processor.

 You may also find that an Optiplex GX620, GX745, GX755 Mini tower is a better upgrade and COSTS less because it already comes with a faster Processor and 305W power supply.

ok will this Power supply Be Compatible with the OptiPlex GX280 because I heard that only PSU’s directly from Dell will only work in dell computers. accessories.dell.com/.../productdetail.aspx

or do i have to buy a Dimension 8400 350W Power Supply ?