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Is this right? RAM appears to run below advertised specs

I just started up Memtest86+ on this new build, but the specs it lists for the RAM seem off compared the advertised specs. Two lines in particular concern me:
Settings : RAM : 778 MHz (DDR3-1557) / CAS : 8-8-8-24 / Dual Channel

and several lines down
- Slot 0 : 2048 MB PC3-10600 - PNY Electronics PNY Technologies, *XMP*
- Slot 1 : 2048 MB PC3-10600 - PNY Electronics PNY Technologies, *XMP*

The advertised specs for these sticks are DDR3 1600 (PC3 12800), CL8. I'll have the results of roughly 8 hours of Memtest86+ in the morning, but, in the meantime, any thoughts, advice, or other info I should pull?
8 answers Last reply Best Answer
More about right appears advertised specs
  1. Memtest is often wrong on timings and speeds. This is especially true when your system has a new chipset.

    That RAM may have several profiles stored in the SPD chip, so Memtest is probably reading one of the slower profiles instead of reading the one that's in use.
  2. Just shy of 9 hours with no errors on Memtest86+. Is there a preferred method of checking the speed and timings on these sticks? I just want to be sure they are performing as advertised.
  3. You can use CPUZ to verify the clocks and timings. It runs in windows.

    Note that those advertised specs on your RAM refer to the speeds at which the RAM itself is rated to run. Your memory controller may or may not be able to operate at 1600 MHz (data rate). Anyway, if your RAM is not running at 1600, you may have change a setting in BIOS.
  4. From the CPUZ report:
    Chipset
    -------------------------------------------------------------------------
    
    Northbridge            Intel Sandy Bridge rev. 09
    Southbridge            Intel ID1C44 rev. 05
    Graphic Interface        PCI-Express
    PCI-E Link Width        x16
    PCI-E Max Link Width        x16
    Memory Type            DDR3
    Memory Size            4096 MBytes
    Channels            Dual
    Memory Frequency        802.4 MHz (1:6)
    CAS# latency (CL)        8.0
    RAS# to CAS# delay (tRCD)    8
    RAS# Precharge (tRP)        8
    Cycle Time (tRAS)        24
    Command Rate (CR)        2T
    MCHBAR I/O Base address        0x0FED10000
    MCHBAR I/O Size            19456
    MCHBAR registers   
    
    Memory SPD
    -------------------------------------------------------------------------
    
    DIMM #                1
        SMBus address        0x51
        Memory type        DDR3
        Module format        UDIMM
        Manufacturer (ID)    PNY Electronics (7FBA000000000000)
        Size            2048 MBytes
        Max bandwidth        PC3-10700H (667 MHz)
        Part number        PNY
        Manufacturing date    Week 18/Year 11
        Number of banks        8
        Nominal Voltage        1.50 Volts
        EPP            no
        XMP            yes
        XMP revision        1.2
    JEDEC timings table        CL-tRCD-tRP-tRAS-tRC @ frequency
        JEDEC #1        6.0-6-6-16-23 @ 444 MHz
        JEDEC #2        8.0-8-8-22-30 @ 592 MHz
        JEDEC #3        9.0-9-9-24-34 @ 666 MHz
    XMP profile            XMP-1600
        Specification        PC3-12800
        Voltage level        1.650 Volts
        Min Cycle time        1.250 ns (800 MHz)
        Min tRP            10.00 ns
        Min tRCD        10.00 ns
        Min tWR            15.00 ns
        Min tRAS        30.00 ns
        Min tRC            50.63 ns
        Min tRFC        110.00 ns
        Min tRTP        7.50 ns
        Min tRRD        7.50 ns
        Command Rate        2T
    XMP timings table        CL-tRCD-tRP-tRAS-tRC-CR @ frequency (voltage)
        XMP #1            6.0-6-6-18-31-2T @ 600 MHz (1.650 Volts)
        XMP #2            8.0-8-8-24-41-2T @ 800 MHz (1.650 Volts)
    
    DIMM #                2
        SMBus address        0x53
        Memory type        DDR3
        Module format        UDIMM
        Manufacturer (ID)    PNY Electronics (7FBA000000000000)
        Size            2048 MBytes
        Max bandwidth        PC3-10700H (667 MHz)
        Part number        PNY
        Manufacturing date    Week 18/Year 11
        Number of banks        8
        Nominal Voltage        1.50 Volts
        EPP            no
        XMP            yes
        XMP revision        1.2
    JEDEC timings table        CL-tRCD-tRP-tRAS-tRC @ frequency
        JEDEC #1        6.0-6-6-16-23 @ 444 MHz
        JEDEC #2        8.0-8-8-22-30 @ 592 MHz
        JEDEC #3        9.0-9-9-24-34 @ 666 MHz
    XMP profile            XMP-1600
        Specification        PC3-12800
        Voltage level        1.650 Volts
        Min Cycle time        1.250 ns (800 MHz)
        Min tRP            10.00 ns
        Min tRCD        10.00 ns
        Min tWR            15.00 ns
        Min tRAS        30.00 ns
        Min tRC            50.63 ns
        Min tRFC        110.00 ns
        Min tRTP        7.50 ns
        Min tRRD        7.50 ns
        Command Rate        2T
    XMP timings table        CL-tRCD-tRP-tRAS-tRC-CR @ frequency (voltage)
        XMP #1            6.0-6-6-18-31-2T @ 600 MHz (1.650 Volts)
        XMP #2            8.0-8-8-24-41-2T @ 800 MHz (1.650 Volts)
    Both DIMMs are showing "Max bandwidth PC3-10700H (667 MHz)", and the Chipset report shows "Memory Frequency 802.4 MHz (1:6)". The CL, at least, seems to be correct, but what's with the frequencies? The XMP profile (which I turned on in the BIOS) is showing the correct 1600 and PC3-12800 at 1.65V, but down below, on the timings table, #1 is something way off, and #2 shows the correct timings but at 800MHz. Also, this mobo should be able to handle DDR3 1600, no?
  5. "Memory Frequency 802.4 MHz" This means your RAM is running at 1600 MHz (data rate). Your RAM clock is fine and it looks like it's running at the CL8 timings, which is good.

    The "SPD" tab is just reading a little text file which is encoded on the RAM sticks. It doesn't give you any info about how your system is actually running. :) The "memory" tab in CPUZ is the one that gives you info about how your stuff is running.
  6. Best answer
    Settings : RAM : 778 MHz (DDR3-1557) / CAS : 8-8-8-24 / Dual Channel

    Running at 778 * 2 = 1556 MHz which is due to the BCLK fluctuations {normal}. CPU-z reports I/O bus clock and not the Data rate which is 2 clocks per cycle or "DDR3 = Double Date Rate revision 3". Next, "Max Bandwidth" per CPU-z is the e.g i7-9xx spec 1066 MHz / 2 = 533 MHz or Sandy Bridge's 1333 MHz / 2 = 667 MHz spec etc per your CPU. The "JEDEC" are speeds and CAS Timings available and programmed 'SPD' or Intel's 'XMP' in the module(s).

    Hope that help! :)
  7. jaquith said:
    Settings : RAM : 778 MHz (DDR3-1557) / CAS : 8-8-8-24 / Dual Channel

    Running at 778 * 2 = 1556 MHz which is due to the BCLK fluctuations {normal}. CPU-z reports I/O bus clock and not the Data rate which is 2 clocks per cycle or "DDR3 = Double Date Rate revision 3". Next, "Max Bandwidth" per CPU-z is the e.g i7-9xx spec 1066 MHz / 2 = 533 MHz or Sandy Bridge's 1333 MHz / 2 = 667 MHz spec etc per your CPU. The "JEDEC" are speeds and CAS Timings available and programmed 'SPD' or Intel's 'XMP' in the module(s).

    Hope that help! :)

    That's exactly what I needed to know, thanks.
  8. Best answer selected by cortillaen.
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