Gigabyte GA-P55A-UD4 i( 760 + DDR3 PC16000 F3-16000CL9D-4GBRM

[tize]

Hi,

my config :
Gigabyte GA-P55A-UD4
I5 760 @ 4000 Mhz
RAM 2000 Mhz 2x2GB Gskill Ripjaws F3-16000CL9D-4GBRM
VDIMM 1.6v

This config is stable with OCCT.

I've bought another 2x2GB F3-16000CL9D-4GBRM, and now I can't configure RAM at 2000Mhz. I've freeze when I boot, no access to bios.
The RAM is only accepted at 1600 (200 x 8). If I put the coef to 10, freeze no access to bios.

What the setting shoud I use ?

I think the pb come from QPI/VTT, which setting shoud I use ?

thanks for your help

/Nicolas

[Tradesman]

Believe you are on the right track, first I'd start by making sure the DRAM voltage is at 1.65, and CR (Command Rate) is at 2T, then if that is already there or doesn't help, raise the QPI/VTT by +.05 or so

[tize]

thanks for your answer.

May be help other, my setting in bios and now I've no problem with DDR3 PC16000 (2000 Mhz) :
QPI/VTT : 1.35v (default with xmp profile 1.1v)
DDR voltage : 1.66

[tize]

another question :
is it normal behavior : when I had 4 GB my memory timings was 8 9 8 24 1T
and now with 8 GB I can only have 10 10 10 28 2T to have a stable system.

[GSKILL TECH]

What frequency?

It can be many reasons.

A. The two kits can't work together at high frequency.

B. Incorrect QPI/VTT Voltage and/or DRAM Voltage

C. Bad subtimings

D. more troubleshooting to find out

Thank you
GSKILL TECH

[tize]

my setting in bios :
CPU Clock Ratio : 20
- BCLK Frequency : 200
- PCI Express Frequency : 101
- System Memory Multiplier : x10
- Memory Frequency : 1000
- QPI Clock Ratio : Auto
- QPI Link Speed : 6.4 Ghz
- CPU Vcore : 1.31
- CPU PLL Voltage : 1.90
- QPI/Vtt Voltage : 1.35
- Memory timing : 10 10 10 28 110 2T <= impossible to boot if I put 9 10 9 28 2T (GSKILL spec)
- PCH Core : Auto
- DRAM Voltage : 1.64

[Tradesman]

May want to drop the PCI freq to 100, 101 can cause instability on a lot of mobos