Dell XPS 420 --CPU Upgrade

Hello rwbrehm,

The XPS 420 is built on the Dell BTX motherboard.  Your CPU is based upon the MOBO  and its socket.  The 420 has a 775 socket, which is what the Intel Core 2 duo and Core 2 quads fit, the 775 socket.  The 420 MOBO will handle only the 65 nm CPU's, so when you look around look at for a 775 socket 65 nm CPU.

In my two XPS 420's I am running the Core 2 Quad Q6600 which handles very nicely. 

Here is the list of compatable CPUs for your rig:

Installing the processor
The Dell heatsink will work fine. Clean the old thermal paste off with alcohol, pick up some Arctic Silver 5 thermal paste, and apply it to the processor after you install it per the Arctic Silver instructions. Be very careful of the socket when you remove the old processor and install the new one. It is extremely easy to bend one of the tiny little pins, all 775 of them. If you bend one, you likely will not be able to straighten it, and you will need to replace your motherboard. Make sure you update the bios to the latest version BEFORE you switch the processor.
HU587 Conroe Kit, E4300, 1.80G, 2MB, 800FSB, L2
DX483 Conroe Kit, E4400, 2.00G, 2MB, 800FSB, L2
DX485 Conroe Kit, E6320, 1.86G, 4MB, 1066FSB, B2
DX484 Conroe Kit, E6420, 2.13G, 4MB, 1066FSB, B2
MP160 Conroe Kit, E6550, 2.33G, 4MB, 1333FSB
MP162 Conroe Kit, E6750, 2.66G, 4MB, 1333FSB, G0
MP628 Conroe Kit, E6850, 3.00G, 4MB, 1333FSB, G0
WM543 Conroe XE Kit, X6800, 2.93G, 4MB, 1066FSB, B2
MP626 Kentsfield Quad Core Kit, Q6600, 2.40G, 8MB, 1066FSB, G0
MP627 Kentsfield Quad Core Kit, Q6700, 2.66G, 8MB, 1066FSB, G0
UP673 Kentsfield Quad Core Kit, QX6700, 2.66G, 8MB, 1066FSB, B3
RX656 Kentsfield Quad Core Kit, QX6800, 2.93G, 8MB, 1066FSB, G0
PW016 Kentsfield Quad Core Kit, QX6850, 3.00G, 8MB, 1333FSB, G0
C863D Yorkfield Quad Core Kit, QX9300, 2.5G, 6MB, 1333FSB, M1
C864D Yorkfield Quad Core Kit, Q9450, 2.66G, 12MB, 1333FSB, C1
C865D Yorkfield Quad Core Kit, Q9550, 2.83G, 12MB, 1333FSB, C1
C299C Yorkfield Quad Core Kit, QX9650, 3.0G, 12MB, 1333FSB, C0
H786G Yorkfield Quad Core kit, QX9650, 3.0G, 12MB, 1333FSB, C1
X198G Wolfdale Dual Core kit, E7200, 2.53, 3MB, FD, 65W,M0
Y932C Wolfdale Dual Core Kit, E8200, 2.66G, 6MB, 1333FSB, 65W, C0
K905F Wolfdale Dual Core Kit, E8300, 2.83G, 6MB, 1333FSB, 65W, C0
Y935C Wolfdale Dual Core Kit, E8400, 3.0G, 6MB, 1333FSB, 65W, C0
Y934C Wolfdale Dual Core Kit, E8500, 3.16G, 6MB, 1333FSB, 65W, C0
 

Other information can be found here:

http://en.community.dell.com/forums/t/19242670.aspx

Best,

Darrell WV