Corsair Vengeance 1866 memory question

[buzznut]

Hey guys,
I recently purchased a Gigabyte 990FX UD3 motherboard. I have an FX 8120 but have had trouble getting memory to run at its rated speeds. I have checked with Gigabyte's forums and the ones over at Tweaktown also.
First I ran some DDR3 1600 Mushkin 2 X 4GB sticks but couldn't achieve stability at 1600 speed.
Then I tried a Patriot kit, which would run at 1600 but also didn't seem 100% stable.
So I ponied up for a 1866 kit of Corsair Vengeance which is on the mobo approved list. I thought this would be the end of my problems, but I can only get it to run at 1600 speed. I have tried dozens of settings, timings , and various voltages, auto settings and manual and still no 1866 love.

Anyone with BD experience with 1866 memory, I could really use some help here. The board otherwise performs beautifully and I have LLC so it overclocks very well. If I could just get the memory running sat the right speed the system would be perfect.
Thanks for any suggestions.
buzznut

 

[guavasauce]

odd question, what is pointing you to memory instability, and not a different setting?

 

[buzznut]

odd question, what is pointing you to memory instability, and not a different setting?

prime 95

 

[XMSYellowbeard]

It sounds as if you have a BIOS related issue or, your memory controller simply is not stable when OCed at or above 1600. All CPUs do not OC equally. Have you contacted Gigabyte? They should be able to help since the memory is on their QVL.

 

[jaquith]

Assuming CML8GX3M2A1866C9R DDR3-1866 9-10-9-27-2N @ 1.50v

Install:
CPU: | blank | 4GB | blank | 4GB |

BIOS - use the latest

BIOS:
Memory Clock -> 9.33
DRAM Configuration /Enter
DDR3 Timing Items -> Manual
1T/2T Command Timing -> 2T
CAS# latency -> 9
RAS to CAS R/W Delay -> 10
Row Precharge Time -> 9
Minimum RAS Active Time -> 27

DRAM Voltage Control -> 1.50v~1.55v
DDR VT Voltage Control -> ; may need to be increased
NB Voltage Control -> ; may need to be increased

Save & Exit = Yes

Failure try a more standardized JEDEC CAS Timings 10-10-10-30-2T @ 1.50v~1.55v; if that works then it's either a voltage issue {DDR VT or NB Voltage Control}, or an unrealistic Rated CAS.

 

[buzznut]

It sounds as if you have a BIOS related issue or, your memory controller simply is not stable when OCed at or above 1600. All CPUs do not OC equally. Have you contacted Gigabyte? They should be able to help since the memory is on their QVL.

No I have not, but I can do so. The FX CPU has a 1866 Mhz controller so I am not attempting to overclock, but simply to run the kit at its rated speed. This is with the reference clock at 200Mhz. I can actually reach higher speeds with a boost to ref clock, but these settings are not stable either. DDR3 1760 was stable enough to enter windows and run most things, but nothing I've tried so far will allow me to finish running 3Dmark11. I could give a crap about prime95, but this indicates to me that I'm not game stable which is a problem.

I have heard a few folks say that it could be my processor, I even saw one post where the OP had almost the same exact specs as me and same symptoms and his problem was resolved when he replaced his CPU. This kind of easter egging won't help me though, at the moment I have no other CPU so I would rather not RMA on a guess.

Most of the posts I have seen in regards to this issue were resolved by manually setting timings and voltages in the bios. Unfortunately for me, setting those things to exact specifications has not led to 1866Mhz speed and/or stability at 1600 speed. I am currently running my Mushkin set at 1600Mhz and fsb is at 200, my CPU is at 4.4Ghz. This is not prime stable but is stable enough for me to run games, Skyrim being the principle one right now.

In regards to the BIOS, I posted on Gigabyte's forums and it was recommended that I update the BIOS from F5 to F6a beta. There seems to be almost no difference in the BIOS versions, so for now I have discounted BIOS.

Thank you for your response, I will contact Gigabyte and see if they may have some advice for me.

 

[buzznut]

Holy Shnikes!! It worked! The stupid manual says to put the ram in adjacent slots. That was the whole problem. It didn't occur to me to try it the other way because it the PC kept reporting that it was in dual cannel mode. Which it shouldn't be if you aren't using the same channel.

Well, thanks everyone for your suggestions, I feel like a bonehead for not ignoring the manual and just trying it anyway.

 

[buzznut]

Best answer selected by buzznut.

 

[nikorr]

This topic has been closed by Nikorr