Question Help! Get 2+2 DDR3 2400 to work at 1866Mhz on a FX8350

[Thunder66]

Hi,

I have 4 sticks of GSkill 2400 DDR3, 2 are same model and the other two of a different model, but same brand. I can't get them to work in my AMD FX8350 system @ 1866Mhz, I know these DIMMs are of the wrong (higher) speed, and currently they can run at 1600Mhz, but when I try to push them to 1866Mhz, the BIOS won't post. Looking at the SPD table in CPU-Z, the RAM sticks don't have a 933Mhz setting, is this the reason?

I also tried to manually set the timings along with the RAM clock to 933Mhz, but no luck. Any suggestion what timing I should set?
Or by the way, if I only put two sticks in, it works flawlessly at 1866Mhz!

And, the SPD table for two types of sticks have:
685, 761, 800, 1200Mhz (XMP)
The other has:
761,800, 1200Mhz (XMP1), 1200MHz (XMP2)

Since they are so different, and without a 933Mhz, is it necessary to reprogram the SPD of the DIMM in order to get it work? ie, using tool such as Taiphoon?
And, my MB and CPU are all supposed to support 4x4G at 1866Mhz from what I've read.

Some details about my setup:
MB: Gigabyte GA-970A-DS3P BIOS ver: FD
CPU: AMD FX 8350
GPU: Gigabyte GTX1060 3G
Memory: 2 sticks of G.Skill Sniper F3-2400C11D-8GSR, DDR3-2400, CL-11-13-13-31 1.65V, PC3-19200 4Gx2 Intel XMP Ready
2 sticks of G.Skill Trident X F3-2400C10D-8GTX, DDR3-2400 CL10-12-12-31 1.65V, PC3-19200 4Gx2 Intel XMP Ready

Thank you for your help!

 

[MeanMachine41]

You took a risk mixing differing RAM kits which is never a good idea especially with differing CL. If they work at all they would default to the lowest frequency. Both kits are not officially supported by the MB so you are going to encounter issues.

Here is a good article to help understand: https://rog.asus.com/forum/showthre...e-memory-kits!-The-meat-and-potatoes-overview

 

[TJ Hooker]

It could be a result of mixing memory kits, as mentioned above. Or it could be because FX CPUs are only rated for 1866 MHz with one stick per channel. With 2 sticks per channel they're only rated for 1600 MHz. That doesn't mean they 100% can't do that, but from what I've heard the memory controller in FX CPUs wasn't too great.

https://en.wikipedia.org/wiki/Bulldozer_(microarchitecture)#Cache_and_memory_interface