How to correctly set up RAM so it runs full speed?

[rootsrat]

Hi guys. I need some help setting my RAM up in BIOS. I never really understood how to do it properly, and I just realised that I've never done it since I updated mu BIOS some time ago. But, start from the beginning.

 

Here's my spec:

 

CPU: AMD Phenom II X6 1100T

Mobo: ASUS M4A79XTD EVO

RAM: Geil Black Dragon 4GB 1333 MHz CL7 (7-7-7-24) [GB34GB1333C7DC]

 

My RAM is supposed to run at 1333 speed, but I cannot get it to. Here's a my full system report.

 

And here's the RAM section from that report, as that's most important I guess:

 

 

 

RAM

  Memory slots

   Total memory slots 4

   Used memory slots 2

   Free memory slots 2

  Memory

   Type DDR3

   Size 4096 MBytes

   Channels # Dual

   DRAM Frequency 704.8 MHz

   CAS# Latency (CL) 7 clocks

   RAS# to CAS# Delay (tRCD) 7 clocks

   RAS# Precharge (tRP) 7 clocks

   Cycle Time (tRAS) 24 clocks

   Bank Cycle Time (tRC) 33 clocks

   Command Rate (CR) 1T

  Physical Memory

   Memory Usage 60 %

   Total Physical 4.00 GB

   Available Physical 1.56 GB

   Total Virtual 8.00 GB

   Available Virtual 5.04 GB

  SPD

   Number Of SPD Modules 2

    Slot #1

     Type DDR3

     Size 2048 MBytes

     Manufacturer GEIL

     Max Bandwidth PC3-10700F (667 MHz)

     Part Number CL7-7-7 DDR3-1333

     Week/year 40 / 09

     SPD Ext. EPP

      JEDEC #3

       Frequency 761.9 MHz

       CAS# Latency 8.0

       RAS# To CAS# 8

       RAS# Precharge 8

       tRAS 28

       tRC 38

       Voltage 1.500 V

      JEDEC #2

       Frequency 666.7 MHz

       CAS# Latency 7.0

       RAS# To CAS# 7

       RAS# Precharge 7

       tRAS 24

       tRC 33

       Voltage 1.500 V

      JEDEC #1

       Frequency 571.4 MHz

       CAS# Latency 6.0

       RAS# To CAS# 6

       RAS# Precharge 6

       tRAS 21

       tRC 29

       Voltage 1.500 V

    Slot #2

     Type DDR3

     Size 2048 MBytes

     Manufacturer GEIL

     Max Bandwidth PC3-10700F (667 MHz)

     Part Number CL7-7-7 DDR3-1333

     Week/year 40 / 09

     SPD Ext. EPP

      JEDEC #3

       Frequency 761.9 MHz

       CAS# Latency 8.0

       RAS# To CAS# 8

       RAS# Precharge 8

       tRAS 28

       tRC 38

       Voltage 1.500 V

      JEDEC #2

       Frequency 666.7 MHz

       CAS# Latency 7.0

       RAS# To CAS# 7

       RAS# Precharge 7

       tRAS 24

       tRC 33

       Voltage 1.500 V

      JEDEC #1

       Frequency 571.4 MHz

       CAS# Latency 6.0

       RAS# To CAS# 6

       RAS# Precharge 6

       tRAS 21

       tRC 29

       Voltage 1.500 V

 

 

As you can see it's running at around 666 MHz, despite my BIOS settings:

 

    

 

I set it accordingly to the information on the manufacturer's website, and I left the stuff I wasn't sure about on AUTO. I also noticed that the report file (it's also in Spoiler section above) states this: Max Bandwidth PC3-10700F (667 MHz) - and yet the mobo specs clearly state that it can handle up 1666 MHz RAM.

 

I lack the technical knowledge to solve this puzzle unfortunately, so I was hoping for someone with more experience to help me, as my RAM is seemingly running at only half of it's speed! 

 

Thanks in advance guys!

[phazer11]

Your RAM is running at full speed.

See here:

 

RAM: 4.00GB Dual-Channel DDR3 @ 666MHz (7-7-7-24)

 

 

 

DDR stands for Double Data Rate. The 3 is the revision number so Double Data Rate Revision 3. The 666MHz is half the rate your ram is running at since your RAM is a DDR RAM.

[rootsrat]

:facepalm:... ... 

 

Of course. How could I forgot that?! Thanks a lot for this, Phazer! I feel like a proper noob now...

 

Solved :)

[phazer11]

LOL no problem happens to all of us sometimes I'd just glad to be answering someone else's problems instead of bringing up my own.

[WilliamImm]

Although unrelated, for some reason my DDR3-1600 ram is being treated by my BIOS as running at 1333... Setting it to 1600 appears to work fine.

[phazer11]

It's probably your cpu's OEM limit. I know the Sandy Bridge and above CPUs (idk about Bulldozer or Llano) have a spec of 1333 MHz but the motherboards allow you to go over and it's generally safe unless you have a higher voltage.