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help with diagnosing ram problem


pegotico

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I build a HTPC with a gigabyte GA-F2A88XN-WIFI and

A10 6700 cpu.

 

first of all the ram is perfectly fine as it is working excellent on my other rig.

The board has the latest firmware and the cpu supports up to 1866 ram

When I put the 2133 ram (CML8GX3M2A2133C11B) at default which is 1333 I don't get problems but as soon I enter the XMP profile and ram speed is display correctly on bios, windows only displays 4 gigs of ram. If I revert to 1333 then windows will see the 8 gigs of ram. This stupid board is so complicated.

 

thanks in advance

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Might be an initialization problem with one of the two sticks. If you haven't done it yet, try to raise Vdimm a bit. Also set Vnb from the AUTO setting to something slightly over standard*, that should help with higher memory ratios (the NB has an idle power state that might be too low power for DDR3-2133).

 

*start at 1.20V, increase in small steps, but stay below 1.30V

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Im just out of ideas!!!

 

when XMP is enable all settings seem to be correct but I went ahead and put those values 2133, 11-11-11-27, 1.5 manually but when booting I get a boot failure due to bios settings not being compatible with current hardware state. If I just put the frequency manually and leave the timings auto (9-9-9-24) computer boots and sees the 8 gigs of ram but run at 1333.

I also went ahead and play around with the Vnb which at default is at 1.275.

If I go higher up to 1.275 the computer only sees 4 gigs. At 1.275 all the 8 gigs show but memory runs at 1333. I tried so many variations of everything that I lost track!!!

 

I was checking the memory compatibility list and they only list cas9 and cas10 2133 corsair ram. I know they only list the ram they have available for testing and they wont have all the ram for every brand. I see cas11 but from other manufacturers.

 

Is there any other setting I can try? Stupid gigabyte motherboard......

 

the only thing is when I manually put 1866 leaving everything at auto, then it will see 8 gigs and run at 1866 but don't know if timings are all messed up.

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when XMP is enable all settings seem to be correct...

So everything runs fine, but you're missing 4 out of 8GB total, right?

Did you try raising Vdimm a little bit with the XMP enabled?

 

but I went ahead and put those values 2133, 11-11-11-27, 1.5 manually but when booting I get a boot failure due to bios settings not being compatible with current hardware state.

Thats probably because you need to manually put in primary and secondary timings according to the XMP. Inserting only the primaries often does not suffice for faster kits.

 

Stupid gigabyte motherboard...

The Gigabyte GA-F2A88XN-WIFI is a very nice board, with a superb VRM and good component quality in general. It also easily does DDR3-2400 (screenshot).

 

ps: Your bios is up to date?

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raising vdimm with XMP enable. doesn't solve the problem...

 

It does have the latest bios F4, it came with F3 and i updated the bios, but F3 is the one that addresses ram.

 

What would be the secondary timings for my ram?

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+++UPDATE++++++

 

I think that I was either going crazy or making someone else crazy. After everything, I remember I had an old A6 5400k around from an old build, so I went ahead and change it with the A10 6700 as I had nothing to loose. To my surprise I just had to enable XMP, and ram is working perfecto!! So now this means my 6700 cpu has problems??? Should I start thinking about RMA the cpu?

 

thanks again and sorry for the trouble :sunglasse

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Hmmmmm maybe 6700 wasn't seated perfectly. Or it has a weak mem controller. I'd put it back in and see. Try boosting cpu voltage if you put it back in and it doesn't work. Seams odd but I've seen cpu voltage helping memory issues quite a bit lately due to boards absolute bare minimum power states. Makes me miss the days of first gen i7 of just turning off all power saving stuff and going balls to the walls. Screw the hydro bill. Moarrr ghz !!!!!
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Hmmmmm maybe 6700 wasn't seated perfectly. Or it has a weak mem controller. I'd put it back in and see. Try boosting cpu voltage if you put it back in and it doesn't work. Seams odd but I've seen cpu voltage helping memory issues quite a bit lately due to boards absolute bare minimum power states. Makes me miss the days of first gen i7 of just turning off all power saving stuff and going balls to the walls. Screw the hydro bill. Moarrr ghz !!!!!
I think it was seated correctly but who knows, I did boost a little the cpu voltage but resulted in boot failure directly to the bios, other settings would cause BSOD
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  • 3 months later...

Is there a solution to this 8GB/4GB problem?

 

I have encountered the same problem with the same RAM (CML8GX3M2A2133C11B), same motherboard (Gigabyte GA-F2A88XN-WIFI), same BIOS (F4), different CPU (AMD A10 7800), and different operating system (Linux).

 

In addition I find that the RAM is unstable at 2133MHz at default settings: the PC will freeze either in the BIOS or when the OS has loaded.

 

A partial solution is to increase the RAM voltage from 1.5V to 1.65V. That at least gives me 8GB (usually) and allows the OS to start.

 

However the OpenGL test program "glxgears" will freeze the PC almost immediately. Even at 1333MHz, "glxgears" will eventually freeze the PC.

 

If I replace the CML8GX3M2A2133C11B with 1333MHz CMV4GX3M2A1333C9 then the PC will work flawlessly. And the CML8GX3M2A2133C11B will work flawlessly in an older 1333MHz motherboard and CPU (Gigabyte GA-P35C-DS3R, Intel Core 2 Duo E6750).

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