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CMZ8GX3M2A1866C9 runs only at 1333, but why?


Slamke

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Hey folks,

 

I have a question. I just bought the system that is displayed above, but I can't get my RAM to run @ 1866MHz without frequent bluescreens. I tried to adjust the timings manually and to increase the voltage, but it didn't help. Both BIOS and CPU-Z say that its maximum bandwidth is only 667MHz....

 

What could be the problem?:confused:

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Well, everything works fine for the first couple of minutes, but then I get a bluescreen. The last one was just now :/

 

So the system is somehow not stable. I'm wondering if this can have anything to do with the graphic processor? Plaing around with the RAM-speed apparently also alters the shader-frequency. SIS Sandra (I know, probably not the best software to tell me that) says that the shaders run at 685MHz right now instead of the normal 600MHz...

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I tried it with increasing the RAM voltage, without much success. So now I'll try to increase the NB/CPU voltage as well, thanks for the advice.

 

But shouldn't it work without these modifications? And shouldn't CPU-Z and the BIOS say that the maximum frequency is 1866MHz instead of 1333MHz?

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But shouldn't it work without these modifications?
Sounds like the AMD memory controller is requiring more voltage than an Intel system.

 

 

shouldn't CPU-Z and the BIOS say that the maximum frequency is 1866MHz instead of 1333MHz?
No, as it's just a label. It's like putting 50 MPH on the side of your car when you're going much faster.
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Ah alright, that's good to know.

 

I read in another forum that someone made it work by maually adjusting those values:

 

9-10-9-27

Command Mode 2

Row Cycle Time 48

READ to PRE Time 7

RAS# to RAS# Delay 7

WRITE to READ Delay 7

WRITE Recovery Time 14 DRAM Clock

FOUR ACT WIN Time 36

REF Cycle Time 160ns

 

Right now I'm trying out these settings, and it actually seem to work now. Are these timings correct? Especially the Row Cycle Time?

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  • 2 weeks later...

Sorry for the late reply, I was gone for quite some time.

I asked the ASUS support for the secondary timings of my RAM, and they said that only the manufacturer of the RAM knows them.

 

Sooo, how do I find out about the correct timings?

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  • 7 months later...

I have same problem. I just bought CMZ8GX3M2A1866C9 and on gigabyte's easy tune 6 It seems 667mhz(pc3-10700H) same with bios. I hoped 1866mhz speed , I didn't buy 1600mhz ones cuz of it. But I got 1333mhz.

 

Plus It seems It has 9-10-9-24 timings with 1.5V right now. But It wrotes it should work at 1866mhz with 9-10-9-24 timings and with 1.5V.

 

If I overclock it to 1866mhz manuel with over volataging (1.65V) so what's this memory's speciality. I could buy any standart memory.

 

What is the problem ?

 

http://s15.postimage.org/xzsyjb7a3/ram_timings.jpg

 

It looks like it should work on 934mhz. And It looks like it can work with 10-9-27-47 with 1.5V(why every voltage writes as 1.50V except 934mhz 1.500V lol) as it already should to be.

 

But I don't know how to do it 934.

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What you are seeing is just the SPD information that is hard coded into the modules and has nothing to do with the actual speed the memory is running at.

 

The part nu,ber listed on your screen shot is in fact 1866mhz. But to get them to run at 1866mhz you will need to set them manually in your BIOS .

 

The owners manual for your MB covers this.

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Spider, check to see if you have the latest BIOS for your MB and if not please flash it to the latest version.

 

Then all you should have to do is load set up defaults and enable XMP in your BIOS. XMP is covered in your owners manual, so please refer to that for instructions on how to enable it.

 

If it still gives you problems you may need to add a slight amount of voltage to the DIMMs. Start out at 1.55v and add .1v after that if you need to. but do not exceed 1.6v

 

Let us know how you make out.

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Well my bios seems on latest version. I didn't try to set them again yet. Beceause it started to have blue screen for a second(couldnt read) and restart rarely since I changed the settings manually and set them back to their regular settings.

 

I'm worried about if It damaged or not. I just set trcd to 9 to 10 and tras 24 to 27. Other cl and trp were already 9. And I didn't changed them. After on first restart It crashed on windows startup screen. So I changed them to back. It was all I did. I'm not sure If it was enough to damage rams.

 

I think I'll not try to overclock it until I solve this blue screen problem. Also even if I wouldn't got to this point. (I just don't know and want to learn) Still would I need to add a voltage to it. Cuz It writes , It should work on 1,5V with 1866mhz. With overvoltage I guess every normal ram could be 1866. So whats the point of spending 10-15 dolars more to buy this one rather than regular one.

 

What do you suggest me to do ?

 

and thank you for your kind responses/help

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I'm worried about if It damaged or not. I just set trcd to 9 to 10 and tras 24 to 27. Other cl and trp were already 9. And I didn't changed them. After on first restart It crashed on windows startup screen. So I changed them to back. It was all I did. I'm not sure If it was enough to damage rams.

You can't damage the modules by changing the timings, just cause instability. Voltage on the other hand is another thing. Too much will dmage the modules, and those will take up to 2.0v before you would need to be concerned about damage and or voiding the warranty.

 

Still would I need to add a voltage to it. Cuz It writes , It should work on 1,5V with 1866mhz.

It's possible you would need more voltage. For the most part most machines will run them at 1866 with 1.5v but some do require more. There are MB's that do not regulate voltages they way they are supposed to and supply slightly less than what is actually being reported in the BIOS. You may need to set them to something like 1.55v-1.6v.

 

With overvoltage I guess every normal ram could be 1866. So whats the point of spending 10-15 dolars more to buy this one rather than regular one.

Not so! It really depends on the modules and the chips used to build them. Some generic modules might gain a couple of hundred mhz at most no matter how much voltage you throw at them. Some won't overclock at all.

 

What do you suggest me to do ?

 

This is what i would do, start out by loading set-up defaults and then enable XMP.

 

Then manually set the voltage to 1.55volts and see what happens.

 

We may still need to add memory controller voltage to that too.or even a little more to the DIMM's But lets see what happens when just adding a small amount to the DIMMS first.

 

Let us know how you make out! :)

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