Soki shows you how to voltage mod your Chaintech VNF4 Ultra to ram up the memory clocks.

Here is the vdimm mod for Chaintech vnf4 ultra, with nforce4 ultra chipset,
contributed generously to us by soki.

Its very simple, find the IC named LM358 under the first black dimm socket. The
area to search for is circled in green:


Connect a variable resistor of 50Kohm between legs 5 & 8. Lower resistance to
increase vdimm, with about 10 Kohms you have ~3.3V, depends from the +3.3V ATX


Measure Vdimm at any of the spots shown below.

Another thing I notice is either Chaintech has OVP or it is a bios bug, but
over 3Vdimm, after some restarts or crashes, the settings in bios for vdimm if
you have a value of “2,7” or “2,8” for example it resets it to “default”, so I
suggest to leave it “default” and controlling the vdimm according to your needs
via the vdimm mod.

Some of soki’s overclocking results can be read