Overclocking/complete Utilization of installed memory problem.

I built my new PC a few days ago, everything started up good no problem, no errors, runs like a beast. I'm able to overclock my CPU to 4.5 (8 core) and video card no problem....but windows is saying that out of my 32gb of ram, only 16gb is being used...and also....my ram is advertised to be running at 1866 but is somehow defaulted in my system at 1333 and is also only using single channel..even though I have the same model of RAM in all 4 slots, and my system wont let me clock it to 1866 or overclock higher without failing to boot and defaulting to original ram settings. My motherboard has a LED readout of error codes that I can easily read even with my case on, but sometimes it is changing numbers quickly so its possible there could be multiple errors. I'm thinking I either have shitty ram or user error, or just need to adjust something.

I'm a noob when it comes to these things, so any insight to this problem is much appreciated.

Operating System: Windows 8 Pro 64-bit (6.2, Build 9200

Motherboard: ASRock fatal1ty 990fx pro "http://www.newegg.com/Product/Product.aspx?Item=N82E16813157267"
RAM: G.SKILL Ares Series 32GB (4 x 8GB) 240-Pin DDR3 SDRAM DDR3 1866 "http://www.newegg.com/Product/Product.aspx?Item=N82E16820231560"

BIOS: BIOS Date: 10/12/12 15:21:32 Ver: 04.06.05
Processor: AMD FX(tm)-8150 Eight-Core Processor (8 CPUs), ~3.6GHz
Memory: 32768MB RAM
Available OS Memory: 16336MB RAM
Page File: 2677MB used, 30042MB available
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More about overclocking complete utilization installed memory problem
  1. Any RAM frequency above 1333Mhz with an AMD CPU is considered an overclock and must be done manually. Remember, the memory controller resides on the CPU in all modern processors.

    The most recent BIOS should be dated 10/18/12 according to the website:
    That BIOS is required for Win 8 support, so that might be the issue.
  2. Ive installed the 10/18/2012 BIOS but the system still says 10/12/12

    I bought the ram in two 16gb packages(total 32)..meaning 2 8GB dual channel Ram units in each package. I don't know a lot about RAM, but could it be a compatibility issue? Or perhaps I should have bought a 32gb kit instead of 2 16's?
  3. Well, what does BIOS say? Is it reporting the full 32GB?

    If so, get memtest, burn to disk, and let it run overnight.

    If not, try swapping out the RAM, by testing each stick individually in the first slot of the first channel (keeping in mind that this may not be the slot closest to the CPU - see your manual)

    If you have all 32GB in BIOS and memtest is fine with all 32GB, then it must be something else.

    I have to wonder about running 4 sticks of RAM at 1.35V with this setup. I can see that as an issue. An increase in voltage might be needed.
  4. Ran memtest everything checks out fine..the BIOS as well as Windows recognizes all 32GB...but Windows says "Installed memory 32GB..but that only 16GB is usable..which I thought was only a problem on 32 bit...so I haven't the slightest idea on that issue..

    Each stick of the RAM is running at 1.5v at 1333...and voltage is set to auto...either my motherboard or the RAM experience an error when trying to overclock to 1866 or 2133
  5. http://sites.amd.com/us/Documents/AMD_FX_Performance_Tuning_Guide.pdf

    Quote from page 15
    The Memory controller of AMD Phenom and AMD Phenom II CPUs can be set to run in Ganged mode or in
    Unganged mode. Ganged mode means that there is a single 128bit wide dual-channel DRAM Controller (DCT)
    enabled. Unganged mode enables two 64bit wide DRAM Controllers (DCT0 and DCT1).
    The recommended setting in most cases is the Unganged memory mode. Ganged mode may allow slightly
    higher Memory performance tuning and performs well in single-threaded benchmarks.
    Depending on the motherboard and BIOS, it may be required manually setting the timing parameters for each
    DCT (in Unganged mode) when performance tuning the memory or fine tuning the timings. Some BIOS
    versions apply the same timings automatically for both DCTs in an Unganged mode.
    The DIMM slots furthest away from the CPU socket should be equipped first (usually marked as DIMM slot 1&3
    or A2&B2).

    Not sure if this applies to FX, but I do suspect you have some BIOS setting to adjust.
  6. Greetings guys.

    I have an AsRock 990FX Extreme4 with FX-8150, and I have been thoroughly frustrated by this same issue, however, I am running Linux so I had no issues with under utilization.

    On the other hand, my experience with not running at 1866 is/was a problem. I only say "was" because I just took the Kingston HyperX Predator 1866 set of four back to microcenter.

    On FX-8150 the native bus speed is 1866 so that reply indicating that anything above 1333 is considered "OC" does not apply for AM3+ implementations.

    I have observed that installing a single pair of the 8GB DDR3-1866 memory modules, in one of the "dual-channel" slot configurations, yields an automatically recognized DDR3-1866 platform.

    However, as soon as all four slots, i.e. A1-B1, A2-B2, have been populated, the listed setup decremented down to 1600MHz, i.e. all four DIMM sockets listed as being populated with DDR3-1600 memory modules.

    After the later behavior is observed, no settings, manual or otherwise, will allow for a usable system that allows the bios to boot and show DDR3-1866 as the memory setup, until you remove one of the pairs of DIMMS.

    It also does not matter which set you remove, as long as you remove one of the pairs. So A1-B1 or A2-B2 will be automatically recognized as DDR3-1866, but not while being used all at once.

    I also alternated the memory modules being used to make sure I didn't have bad memory, which it seemed that I did not.

    So everything I am saying has been thoroughly tested as mush as I can without an oscilloscope and lab-grade multimeter.

    I too flashed my bios and only discovered that the background of the UEFI interface had changed, and nothing else as far as solving my issues.

    I am going to try it one more time, with some G-Skill memory and if that doesn't work, then I will just call it a day and donate it to my Hackerspace for use in revamping our IT infrastructure.

    Some guy jumped on my thread and talked all this junk about how he "built a similar system and everything just worked," etc.... ( http://www.tomshardware.com/forum/324603-30-asrock-990fx-extreme4-32gb-ddr3-1866-1600mhz#t2160582 )
    I think he either was very lucky, or did something odd to his setup, since he sounded like a professional builder, given the many references to "clients" in his various rebuttaled replies.

    Honestly, I think this is just a cheap board manufacturer and should be avoided on future builds.
  7. Yep, I was living in the past with that 1333 statement. However, there are limitations on that.
  8. Mason24,

    Make sure each kit is installed in the same color slots. It is not a matched 32GB kit, so this can be a potential problem. Should problem persist, send the memory in for RMA to see if a new kit works better. It may also be a defective motherboard, so replacing one or the other should solve your issue.


    DDR3-1866 is still considered OC. The JEDEC standard is DDR3-1333 CL9 and DDR3-1600 CL11, so DDR3 memory can only default up to these values. Anything higher requires manual settings, or enabling of the DOCP/EOCP enhanced performance profiles. The AMD FX CPUs do have a DDR3-1866 memory multiplier, which makes it a little easier for people to configure settings in BIOS.

    Thank you
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