Utilising DDR3 1333 on an Asus M4A78T-E

Hi guys

I have built a PC for a friend with the following hardware:
AMD Phenom 2 720
Asus M4A78T-E
2gb Kingston DDR3 1333

With all of the Bus and Frequency settings set to Auto, the POST screen sows the RAM as DDR3 1333
However CPU-Z shows the following settings:

Core Speed: 2800
Multiplier: x14
Bus Speed: 200
HT Link: 2000
NB Frequency: 2000
DRAM Frequency: 667
FSB : DRAM: 3:10

The DDR3 1333 RAM is running at 667!

I tried setting the FSB to 334, the CPU multiplier to 8.5, and the NB and HT multipliers to 6.
The resulting settings according to BIOS were:

Core Speed: 2800
Multiplier: x8.5
Bus Speed: 334
HT Link: 2004
NB Frequency: 2004
DRAM Frequency: 1333

The onboard video did not like this, it made the screen go al lfuzzy, so i disabled it and used a video card instead. I was able to boot into Windows fine, but lo and behold, this is what CPU-Z said:

Core Speed: 2800
Multiplier: x8.5
Bus Speed: 334
HT Link: 2004
NB Frequency: 2004
DRAM Frequency: 667

The RAM was still running at 1333!
The RAM:FSB ratio was different, but i cannot remember what it was, i know it changed tho.

I set the FSB to 250, and set all the multipliers to maintain stock settings again. Booted back into windows and CPU-Z said:

Core Speed: 2800
Multiplier: x11.5
Bus Speed: 250
HT Link: 2000
NB Frequency: 2000
DRAM Frequency: 667

The RAM:FSB ration had changed AGAIN to make sure the RAM stayed at 667!

I cannot see what setting within BIOS is doing this.
Why would it be automatically changing the RAM frequency like this?
5 answers Last reply
More about utilising ddr3 1333 asus m4a78t
  1. DDR means DOUBLE DATA RATE. 667x2=1333. CPU-Z is saying that your RAM is running correctly.

    Need proof?

    Here is my memory. It's 800Mhz, running on a FSB of 400. It's purring along:
  2. Ah, i see. I thought it was showing the frequency once all calculations are included.

    Thanks! :)

    I don't suppose you know why the onboard video goes fuzzy when i raise the fsb?
  3. I will guess because you overclocked so high you were pulling juice away from your GPU. :)
  4. Would it help to raise the voltage on the GPU?
  5. No. Might help to have a quality PSU? You haven't listed it.
Ask a new question

Read More

Chipsets DRAM Frequency DDR3 RAM Motherboards