GA890FXA-UD5 - won't boot with with more then 2 sticks of RAM

[JonathanCharlessummers]

Hello, This has got me a little baffled. I have 4 sticks of G Skill 4Mb RAM. With one stick in Slot 1 machine boots. With another stick in slot 3 it does not. However with one stick in Slot 1 and another in slot 2 it does. How does this make sense. And needless to say with all RAM slots filled in it will not boot.

Once I had established the stick in one worked I tried the remaining 3 in slot 3 and still the same so I don't believe I have a stick of bad RAM. With the configuration I have it works fine, albeit with only 8GB of memory but this makes me wonder if there is something more fundamental wrong like not enough power or CPU blown up?

[absic]

Hi there,

What CPU are you running?
Which revision is your motherboard?
What version is your BIOS?
What is the part No. for your RAM?

[JonathanCharlessummers]

What CPU are you running?

Number of cores      3 (max 4)
   Number of threads   3 (max 4)
   Name         AMD Phenom II X4 965
   Codename      Deneb
   Specification      AMD Phenom(tm) II X4 965 Processor
   Package       Socket AM3 (938)
   CPUID         F.4.3
   Extended CPUID      10.4
   Brand ID      14
   Core Stepping      RB-C3
   Technology      45 nm
   Core Speed      3415.7 MHz
   Multiplier x FSB   17.0 x 200.9 MHz
   HT Link speed      2009.2 MHz
   Instructions sets   MMX (+), 3DNow! (+), SSE, SSE2, SSE3, SSE4A, x86-64, AMD-V
   L1 Data cache      3 x 64 KBytes, 2-way set associative, 64-byte line size
   L1 Instruction cache   3 x 64 KBytes, 2-way set associative, 64-byte line size
   L2 cache      3 x 512 KBytes, 16-way set associative, 64-byte line size
   L3 cache      6 MBytes, 48-way set associative, 64-byte line size
   FID/VID Control      yes
   Min FID         4.0x
   P-State         FID 0x12 - VID 0x10 - IDD 21 (17.0x - 1.350 V)
   P-State         FID 0xB - VID 0x18 - IDD 15 (13.5x - 1.250 V)
   P-State         FID 0x6 - VID 0x20 - IDD 11 (11.0x - 1.150 V)
   P-State         FID 0x100 - VID 0x30 - IDD 4 (4.0x - 0.950 V)

Which revision is your motherboard?

GA-890FXA-UD5 (rev. 2.0)

What version is your BIOS?

F6

What is the part No. for your RAM?

G.Skill DDR3-1333 8GB Dual Channel [Ripjaws] F3-10666CL9D-8GBRL

Many thanks for your interest.

[absic]

Hi again,

Just want to double check something here. The RAM you have is it actually a 16 Gig Set made up of 4 x 4 Gig modules  or is it two sets of 2 X4 Gig?

The fact that you can run with RAM in slots 1&2 would mean that the problem isn't quite so likely to be with the CPU but is more likely to be with something else. Have you actually run MemTest on each of the sticks individually to see if any of them are faulty?

If you are happy that your RAM is OK then you could try slowing them down to 1066MHz, in the first instance, to see if you can actually get the system to BOOT with all four modules installed.

At this stage it is a process of elimination until we can find out exactly where the problem lies I'm afraid. Sorry there's no nice and easy answers for you. 

[JonathanCharlessummers]

"The fact that you can run with RAM in slots 1&2 would mean that the problem isn't quite so likely to be with the CPU but is more likely to be with something else. "

It dawned me me yesterday while I was compiling that information for you that this is a "new" system because I was having similar problems wit the old one.  So I bought a new motherboard and new RAM and the problem is not going away.

The only system components that are the same (common) to both are the CPU, video card and hard drives.  Could this point to the CPU's memory controller/s  having blown up?

What I will do is try a different CPU and if that does not improve things test memory and the rest as you suggest.

again many thanks for the interest and help.

[absic]

Although it is possible that the problem lies with the CPU I really feel that it is something else. The reason I say this is that on the Rev 2.0 version of this motherboard slots 1 & 2 are used for Dual Channel Mode. You can check if this is the case when you first switch on the PC as it will show you on the POST Screen. If it is running in Dual Channel Mode then your CPU is probably OK as both channels are working with one stick of RAM accessing one channel whilst the other is accessing the second. Of course, it might be that the CPU memory controller is faulty and that the increased throughput by adding the extra RAM is overloading the memory controller in some way.

However, the fact that your system is working with RAM in slots 1 & 2 but not if you put the RAM in slots 3 & 4 would realistically point to the problem being with the motherboard or other components.

Sadly, the only way of knowing for certain is undertake the steps that you are taking. If you can swap the CPU then it would give a good indication if the problem really is there. Of course, if the same symptoms exist then you still have to find out what is causing it.

[JonathanCharlessummers]

Although it is possible that the problem lies with the CPU I really feel that it is something else. The reason I say this is that on the Rev 2.0 version of this motherboard slots 1 & 2 are used for Dual Channel Mode. You can check if this is the case when you first switch on the PC as it will show you on the POST Screen. If it is running in Dual Channel Mode then your CPU is probably OK as both channels are working with one stick of RAM accessing one channel whilst the other is accessing the second. Of course, it might be that the CPU memory controller is faulty and that the increased throughput by adding the extra RAM is overloading the memory controller in some way.

However, the fact that your system is working with RAM in slots 1 & 2 but not if you put the RAM in slots 3 & 4 would realistically point to the problem being with the motherboard or other components.

Sadly, the only way of knowing for certain is undertake the steps that you are taking. If you can swap the CPU then it would give a good indication if the problem really is there. Of course, if the same symptoms exist then you still have to find out what is causing it.

OK here we are so far.

The CPU I thought could fit was in fact a Phenom not  a Phenom II 

I tried all sticks of memory in all combinations and the ONLY combination that works is with the RAM in slots 1 & 2.  I unplugged everything that was not keeping this baby in the air but still the same.

Now when I was doing all this I notices a 3 pronged pronger labelled "NB_FAN".  As I have no separate North Bridge fan what do I do with it?

Jonathan

[JonathanCharlessummers]

Hi all that have helped.

Bought and installed a  new CPU.  I can report all memory problems dissappeaed and system working as expected.  Existing fauly CPU has been hurled.

Jonathan