Q&A for the topic VERY IMPORTANT INFORMATION REGARDING AMD AM3 CPU's & RAM....

[Dark Mantis]

Ah, takes me back. One hand on the zimmer frame and one on the cue!

[absic]

And it always amazed me how you could also hold a pint of beer too! 

[Dark Mantis]

You know how it is absic...where theres a will... multitalented!

[absic]

you almost let it slip out there, didn't you?

By the way, I always thought it was..... Where there's a will there's a relative. 

[Dark Mantis]

Usually more than one...brings them out of the woodwork. Often never even heard of them before!!

[absic]

Daddy!!! 

[CrankyPants]

This thread (and the sticky) have been very helpful, since I unknowingly bought two 4 gig sticks at 1600 freq. ram for my Phenom ii 965 BE, and after much frustrating snooping have decided that downclocking it to 1333 might be best for now.

However, what are my options IF i want to hit 1600 with my ram? You mentioned earlier that:

Unganged Mode is where each of the Memory Controllers on the CPU work independently and equals 2X64 bit Channels. (I can run my RAM at 1600 Mhz only in this mode)

Were you able to run it at 1600 in this mode with/without BIOS tweaking? I had my two sticks in unganged mode and it was unstable, but that was without any other changes. The Gskill forums suggested (quoting AMD) that for 1600 ram, increasing the CPU NB freq to 2400 was ideal, along with upping the voltage slightly (though I don't know what "slightly" is). I don't do much overclocking, so how much would these increases affect my system long-term?

I'm currently erring on the side of caution, but if these changes are slight and could noticeably increase performance, it might be worth it, no? I'm sure others are asking themselves the same.

[absic]

Hi there,

if you could post back with your system specs it would be easier to offer practical advice. In particular your motherboard and RAM details would really help.

[CrankyPants]

Hi, thanks for replying!

Specs:

CPU: Amd Phenom ii x4 3.6 Black Edition
MB: Gigabyte GA - 870A-UD3, BIOS Rev 0.0
RAM: G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBRL
Video: Radeon 4870
PSU: Antec TP New 750w

Hope that helps

[absic]

Hi again,

the revision number of your motherboard can be found on the bottom left hand edge/corner of the board itself or on the label on the box it came in.
It will be either: 2.0; 2.1; 2.2 or 3.0 and this is important as, depending on which revision your board is, will dictate how best to configure your RAM.
Also the BIOS version you are using should be shown on your POST screen but if you go into BIOS and press the F9 key on the first page it will show you which version you are running. This will probably be shown as F2; F3; F4 or maybe FA

[CrankyPants]

Oops, that's what I get for using Cpu-Z...

I found it on the box: Rev 2.1

edit: And Bios is F2 for both main and backup

[absic]

OK

You need to put your RAM Modules into slots 1&3 or 2&4 on your motherboard for dual channel mode.

In the first instance I would suggest that you try just increasing the RAM speed to it's rated 1600MHz. To do this you need to go into the MIT Section of BIOS and change the parameter "Set Memory Clock" from the default x6.66 to x8. Press F10 to save the changes and then reboot your PC.

If doing this results in your system becoming unstable the next step would be to slightly increase the Voltage to the RAM. Again this is done under the MIT Section of BIOS and before you can make any changes to the voltage you have to set the System Voltage Control from Auto to Manual. Once you do this the Options that are greyed out become available. Now this is where you will have to experiment to find the best solution. Usually you can increase the voltage in 0.025V increments. Raise the voltage by +0.025V Save and exit BIOS reboot and see if things are better.

If you are still having issues try raising the NB Voltage control a little and test the system again.

It is often a balancing act between these settings to obtain the best results but, be careful not to go to high with your RAM Voltage as it is rated at 1.5V to start with.

I have to also say though, that you might be better off by just increasing the speed of your CPU and leaving the RAM at 1333MHz which is probably safer for your processor.

[CrankyPants]

Thanks a lot.

Since I already tried running the RAM on x8 in dual channel unganged mode and it was unstable, I'll try your suggestions on the voltage increments.

But since you say that it might be safer to increase the speed of the processor, how exactly would I do that? I thought the CPU-NB controlled the memory and CPU speed, so raising that IS speeding up the CPU. Is this what you mean by increasing the speed of my CPU?

Also, is the BIOS's green/red warning text in the MIT screen (the "warning: system voltages are not optimized or system is optimized" messages) a valid indicator for me of whether or not I'm OCing the processor properly?

[absic]

With the BE edition CPU, that you have, you can increase the speed of the CPU without it affecting the RAM. Basically it is the same as buying a faster processor but at no extra cost. However, the headroom on your CPU is not as great as they are on lower spec'd versions as AMD have already pushed it. I have an X6 1090T Rated at 3.2 GHz but it runs quite happily at 3.8GHz without to much effort.

If you want to try increasing the speed of the CPU all you really need to do is adjust the CPU Clock Ratio. With your CPU it will already be at X18 but you should be able to hit 3.8GHz easily enough just by changing this to X19.. Going above 3.8GHz can prove a little trickier and you might find you need to adjust the CPU Northbridge Frequency along with the HT Link Frequency although I was able to run my old 965 CPU at 4.2GHz without a problem.  But, once again, if you decide to do this you need to make sure that your CPU Cooler is capable of getting rid of the extra heat. It is not a good idea to do this if you are using the stock AMD cooler

Another thing that is advisable when over clocking the CPU is to disable the CoolnQuiet feature along with the Turbo CPU and Core Performance Boost.

The warning dialogues in BIOS are just that a warning. They are not very practical in reality, for example, my RAM is designed to run at 1.64V. By default the motherboard drops it back to 1.5V but when I try to manually set the 1.64V I get an over voltage warning which is clearly incorrect.

You might like to check through this item: http://forum.giga-byte.co.uk/index.php/topic,3637.0.html as it might help. Also look through the overclocking section of the forum as there are some useful pointers to be found there.

[CrankyPants]

Ok thanks; once again very helpful. What you say is interesting since on other forums people have suggested that OCing the BE will also affect the RAM by default, or perhaps they weren't taking the BE into consideration at all. I'll probably just keep the Ram at 1333 and not OC since I'm on the stock cooler and don't want to risk damaging anything.

Another suggestion i've found is to leave the ram at 1333 but tighten the timings for better performance. As it is mine are on stock 9-9-9-24. Would you recommend this? Is it as easy as just changing the numbers once again in the MIT section, or would it require some experimentation, like with the voltages discussion of before?