X48 Rampage Formula Preview.

[mikeyakame]

It isn't possible to change tREF in the BIOS. You have to use MemSet for that. I hope Felix add auto tREF for the ASUS Rampage Formula X48 Chipset.
Mikeyakame already gave him some code to make it easier for him.

ASUS should definitely add it to the BIOS that it sets tREF timing for the memory speed you are using.

Let's see what they have to say about it. They are going to run some tests to find out what should be done to fix the issues with BIOS 0802.

Thats always a start. Now if they'd only take a leaf out of DFIs book and display the current PS skew values it'd be awesome.

DIMM1 Clock Fine Delay 5T
DIMM2 Clock Fine Delay 7T
DIMM3 Clock Fine Delay 5T
DIMM4 Clock Fine Delay 6T

They are my values at 415mhz fsb, cross clocking/common clock aggressive (aka strong) , I'm using a2/b2 for ram so dimm 2/4 which the values of clock fine delay are pretty much how I set them in bios.

Fine Clock Delay Adjust = 30PS (number of degrees times this adjust gives you final ps skew)
Dimm2 Clock Fine Delay = 22 degrees (660ps)
Dimm2 Control Fine Delay = 26 degrees (780ps)
Dimm4 Clock Fine Delay = 19 degrees (570ps)
Dimm4 Control Fine Delay = 22 degrees (660ps)

Dimm4(B2) is advanced 90ps from Dimm2(A2), the base values were around 740ps on clock fine delay for both a2/b2 which I've found using DLL Skew Model 1 for these sticks is the right model to use for delays. Also reducing DRAM CK (clock) and DQ (data) Drive Strength from CK=6, DQ=8 to CK=5, DQ=6 has magically fixed the random memory errors I was getting here and there when using higher drive strengths.

You know the nicest thing though.

Im using 8x415FSB at the moment, and Speedstep/C1E are both enabled and working as should, VID Special Add is amazing. 105.5% VID (1.2875v VID) which gives me 1.34v load, and 1.355v or so idle with Vdroop Compensation enabled. DFI's implementation is nowhere near as aggressive as Asus LLC, still has small droop but its consistent, 0.01-0.02v droop is worst I've seen so far.

Speedstep gives me 6x415 = 2.45ghz, C1E drops Vcc down to 1.22v during speed step. It's stable as could be too with them both enabled. I've never cared much for power saving features mostly because Asus boards never have them working once overclocked, but after experiencing working powersaving when overclocked on this DFI board I don't think I'll be content with broken Asus power saving features anymore!