SOLVED Asus M4a78e-m max RAM speed?

[alegelos]

RAM: 2x 2gb DDR3 PC-2000mhz CL7
Mother: Asus M4a78t-e
CPU: AMD 1055t (arriving in 1 weak+)
CPU2: test on AMD 945

All tested with CPU2 AMD 945. 1055t coming soon, but not yet.
Iam Over Clocking my mother Bus to 250-285mhz in order to OC CPU and also get the RAM frequency to 2000mhz. But only could get Ram running at 1700mhz, more wont boot.

But i read in this:

"However, you have to make sure that the frequency of the North Bridge built into the processor and the frequency of the HyperTransport bus don’t exceed 2.0 GHz that is why you have to lower corresponding multipliers accordingly. The same is true for the DDR3 memory frequency: the actual resulting memory clock shouldn’t exceed what the modules are physically capable of, so you may have to lower the corresponding multiplier as well."


So does it means that i just CANT get my ram running at 2000mhz on this motherboard? :/


Thanks for your time

 

[trents]

You are confusing ram limitations with limitations built into motherboard/bios and/or CPU hardware. With a good detailed bios you can separate the HT Link speed from the CPUNB speed. That is to say, you can adjust each one independently of the other. Neither of them are tied to the speed of the ram. More inexpensive motherboards often do not allow you to manipulate the CPUNB speed apart from the HT Link speed. The goal is to keep the HT Link speed at or below 2000 mhz and the CPUNB speed in the range of 2000-2400 mhz with the CPU you are using. HT Link speed in bios may be expressed simply as "HT something" and is usually given as a multiplier like 2x,3x,4x, 5x. If it rises above 2000 then reduce the multiplier to 4x. CPUNB is easily confused with NB and the bios writers will use them interchangeably sometimes, to add to the conusion. NB has to do with the onboad video controller whereas CPUNB has to do with the integrated memory controller (on the CPU die). To answer your question directly, "No", limitations with the HT Link speed and the CPUNB speed will not limit what speed your ram will operate at. What might limit you with regard to your ram speed is the motherboard or its bios. Does you bios allow you to choose DDR3 2000 speed?

 

[trents]

Are you absolutely sure your are using DDR3 ram and not DDR2? If so, I cannot find a listing of your motherboard on Asus' web site. I was going to download your owner's manual to get a look at your bios options.

 

[alegelos]

Are you absolutely sure your are using DDR3 ram and not DDR2? If so, I cannot find a listing of your motherboard on Asus' web site. I was going to download your owner's manual to get a look at your bios options.

Thanks a lot for reply

1- RAM is DDR3 Mushkin PC-2000mhz CL 7-10-8-27 (same timings set at bios)
2- At the bios i can choose ram speed 1066 - 1333 - 1600. After i OC the mother bus from 200mhz to 260mhz or more, i can choce 2000mhz. But if i do it wont boot . I have to set ram speed to 1700+mhz and it boots.
3- also i update to lastest bios few month ago.
4- i think it could be the CPU 945, and maybe with the 1055t it will boot at ram speed of 2000mhz. I will test that in 1-2 weaks (when it arrive).
5-If the problem is the motherboard, then i will have change it . Not big deal, just buy and sell. And get a 890 gx or fx chip. not sure

 

[trents]

I just cannot find that motherboard on Asus' website, not even the global one. No wait, I found it on NewEgg. Huh? It's a 790 based chipset. From the "78" in the model number I assumed it was a 780 based board.

 

[alegelos]

Thanks again for the help

Here is a Link to Asus m4a78t-e official web page with all its information

Its a 790GX chip, but any way u will see it in few second after u enter the link

Sorry late reply, i was installing 5 new fan coolers to case/cpu. This Fans Cooler Master R4-L2R-20CK-GP are really good! full speed lot of air plus super silence! love them (i was thinking to upgrade to watter cooling whole PC soon but after trying this fans... maybe not).

 

[trents]

"2- At the bios i can choose ram speed 1066 - 1333 - 1600. After i OC the mother bus from 200mhz to 260mhz or more, i can choce 2000mhz."

I'm not following that. In all the bioses I have ever seen, one can either choose 1066, 1333, or 1600 but not all three at once - I don't think, at least. Am I not understanding correctly what you are trying to say? But you also say that there is no choice for 2000 mhz until you OC the system bus? That's the weirdest bios I've every heard of!

Before you bought the ram, did you check to see if your motherboard supported 2000 mhz? According to the Asus website it only goes as high as 1600. However, you should be able to overclock your 2000 mhz ram higher than 1600 by setting the bios to 1600 and then increasing the system bus from the default 200 mhz to whatever it will stand. Whether or not your motherboard components are strong enough to overclock the system bus high enough to get your ram from 1600 all the way to 2000 is another issue. And even if the motherboard will do it, I doubt that your CPU integrated memory controller (ICM) would support ram running at 2000 mhz. That may be why you can't boot when you have it at 1700. The CPU's ICM may not be made for that high.

Do some research on the PII X4 945 and see what is the maximum ram speed it will support.

 

[alegelos]

haha, at the same time as i raise the BUS all other number also raise at the same time. So after i get bus to 260+ iam able to chooce the ram 2000mhz speed or even more.

I mean eve point i raise the bus all other thing (including ram speed frequency) also raise, until it get to 2000mhz.

The new 2000mhz speed would be the 1600mhz speed option that have just raise after raising the bus.

 

[trents]

Yes, overclocking with the "BUS" causes not only the CPU to go faster but also the ram, the HT Link, and the CPUNB. In your case you needn't worry about the ram becoming too fast as you are using 2000 mhz ram and it has lots of overclocking headroom. But you need to lower the HT in bios as you overclock and keep it at 2000 or lower. Also keep the CPUNB at 2000-2400 or it will become unstable as you overclock. There are adjustments for these in bios and you need to find them. Please download and run the program "CPU-z" and take screen shots of the "CPU" tab, the "Memory" tab and the "SPD" tab. This program will tell us much about these things and others as well.

Also, you have said nothing about your core temps. Please download and run Prime95 for at least 10 minutes. It will stress your CPU cores at near 100% to check for intsability. Also download and install "HWMonitor". Have it open while you run Prime95. HWMonitor will monitor temps. Take screen shots of these after running Prime95 for 10 minutes and upload them so we can see. If your cores are getting hotter than 55-58c or so under load it will cause instability.

 

[alegelos]

YES! i already got all those programs. But i still dotn have my new CPU Phenom II 1055t. It should arrive in 1-2 weaks from now.
I will have in mind u said here in my OCing. After i will upload all screen shot etc.

Thanks trents!

 

[trents]

Okay. I just thought you might want to practice the overclocking skills to get ready for the 1055.

 

[alegelos]

thats exactly what iam doing now while also studding for exams he he

My last research is this the “FSB Hole” between 258MHz and 270MHz" ! with my Asus m4a78t-m