Correct BIOS settings for F3-12800CL9D-4GBNQ on a GIGABYTE GA-785GMT-USB3

[jonashat]

I am not sure how to correctly configure my correctly configure my BIOS settings for F3-12800CL9D-4GBNQ to obtain the advertised 1600MHz speed.

My system configuration is as follows:

Processor: AMD Phenom II X4 955 Black Edition Deneb 3.2GHz Socket AM3 125W Quad-Core Processor Model HDZ955FBGIBOX
Mother board: GIGABYTE GA-785GMT-USB3
Memory: G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Dual Channel Kit Desktop Memory Model F3-12800CL9D-4GBNQ

Currently the speed is being automatically recognized as 1333MHz.

[GSKILL TECH]

Dear Customer

Please make the following changes in BIOS and everything should be fine.

DRAM Configuration (submenu)
DDRII Timing - Manual
CAS Latency - 9T
RAS to CAS R/W Delay - 9T
Row Precharge Time - 9T
Minimum RAS Active Time - 24T
1T/2T Command Timing - 2T

System Voltage Control - Manual
Set Memory Clock - Manual
Memory Clock - 1600

Thank you
GSKILL TECH

[Hyram]

I have the same motherboard & RAM as jonashat, except I have the Phenom II X6 1055T processor. I cannot get the machine stable!

Unfortunately your instructions on what to change in the BIOS are not very clear, could you please provide more step-by-step detail?

[GSKILL TECH]

What! They are as clear as possible, you just did not look in the BIOS. If you go into the BIOS, you will see those options, and you just need to change the values as shown.

Thank you
GSKILL TECH

[Hyram]

If I thought they were clear, I would not be asking for more detail, would I

I am not used to dealing with BIOSes, I did try to follow the above settings, but became confused as to where these settings were. Knowing that the BIOS is powerful enough to kill hardware with one wrong setting, I seek clarification before committing the changes.

Imagine I'm a Mac user, and this is my first computer with a BIOS. How would you explain in detail exactly what is needed to be done?

(The mark of a good support officer is not what they know or how much they know, but learning how much the other person knows, and communicating the right steps so they are understood.)

[GSKILL TECH]

Thanks, I understand, but I was just hoping you would enter your BIOS and see all the settings I listed.

When you start your computer, press Del rapidly.

Go into the MB Intelligent Tweaker page.

Then just find all those settings and change the values.

You can also look in your motherboard user's manual, all this information is provided.

Gee, Mac users. haha jk

[Hyram]

The helpful -- and thorough - support staff at GIGABYTE have replied with the corrected instructions on changing the memory timing in the BIOS.

1. Enter the BIOS by pressing the DEL key immediately after starting.
2. Press F6 to load fail-safe defaults
3. Enter the MB Intelligent Tweaker (M.I.T.) screen.
4. Use the arrow keys to select DRAM Configuration and press the Enter key
5. Change DDR3 Timing Items to Manual
6. Change CAS# Latency to 9T
7. Change RAS to CAS R/W Delay to 9T
8. Change Row Precharge Time to 9T
9. Change Minimum RAS Active Time to 24T
10. Change 1T/2T Command Timing to 2T
11. Press the ESC key to return to M.I.T. screen
12. Press up arrow key twice to select Set Memory Clock and change it to Manual
13. Press down arrow key once to select Memory Clock and change it to x8.00 so that the value is 1600MHz.
14. Press F10 to save BIOS settings to CMOS, press Y and then Enter to commit and restart computer with new settings.

They make no mention of changing the System Voltage Control to Manual.

Out of curiosity (and knowing that no changes happen until I save to CMOS and restart) I changed System Voltage Control to manual, but as soon as I did I got the red flashing message "*** System Voltage NOT Optimized! ***"

Either you were wrong and there is no need to mess with the voltages, or you were wrong and did not add what the voltages should be changed to so that the voltages stay optimized.

So, I have the RAM timings set as you mostly described. What happens with the voltages?

[mrcmtl]

You'll need 1.5V on the DRAM and 1.2V on the CPU-NB. The other voltages you can leave them as they are.

[Hyram]

You'll need 1.5V on the DRAM

Do you mean 'DDR3 Voltage Control' on the M.I.T. screen?

If so, there is no direct voltage setting, I can choose Normal, +0.050V, +0.100V, +0.150V and +0.200V. How do I find out what 'Normal' is, so I know how much to add?

and 1.2V on the CPU-NB

Do you mean 'CPU NB VID Control' on the M.I.T. screen?

If so, there is no direct voltage setting, I can choose Normal, or any value between +0.600V and -0.600V in 0.025V increments. How do I find out what 'Normal' is, so I know how much to add or subtract?

[mrcmtl]

For DRAM, leave it at Normal and adjust +0.1V for CPU NB. Get a program like everest to verify what are your current voltage values. Or you can try AMD Overdrive.

[Hyram]

Ahh, now we seem to be getting somewhere.

When I change CPU NB VID Control to +0.100V, it displays the new voltage setting to the right, which reads 1.2500V. You say I need that to be 1.20V, so changing CPU NB VID Control to +0.050V, the value now becomes 1.2000V. This is what we want, yes?

Similar story with the DDR3 Voltage Control setting -- change it, the new value appears, and it appears the 'Normal' value is 1.6000V. There is no way to lower voltage to the value of 1.5V you recommend.

The good news is that changing just the CPU NB VID Control setting has stopped that ugly red flashing message and I've got **** System Voltage Optimized ***** back!

As for using a Windows-based monitoring tool (I heartily endorse Open Hardware Monitor), that would require a working Windows install on this machine, something I have not been able to complete because of this RAM instability issue, so I'm reliant solely upon the BIOS for the moment. The instability is that bad that the PC would hard-lock after 10-20 minutes into the install process, the only way back was to power cycle, but this would for some reason reset the BIOS to failsafe defaults.

[mrcmtl]

Then try 1.6V and 1.2V, see if system is stable.

[Hyram]

An update.

With the above settings, I ran a five our Prime95 stress test and it stayed running.

I am still concerned about Gigabyte's mimum setting of 1.60V for DDR3 Voltage Control, especially after reading this:

"According to JEDEC the maximum recommended voltage is 1.575 volts and should be considered the absolute maximum when memory stability is the foremost consideration."

I sent off a stern letter to the Gigabyte tech people, and they sent me beta BIOS version F4c, which I installed, but it still mis-sets the timings in Auto, and still does not allow DDR3 voltage below 1.60V!

[mrcmtl]

You don't have to worry about JEDEC specifications. These specifications take the standard "value" RAM, and not performance RAM. For example, JEDEC standard for DDR2 is 1.8V while most of the performance kits were running 2V+.

[GSKILL TECH]

1.60V will be fine, The JEDEC standard is 1.50V, but some AMD motherboards are 1.60V minimum due to CPU IMC optimization.

DRAM Voltage 1.60V or AUTO, CPU-NB Voltage +0.1V (1.20V).

Thank you
GSKILL TECH