AM2+ CPU Limitation with DDR2 1066 Explained - Page 2 - Overclock.net

logan · 05-09-09

Quote:

Originally Posted by laurie

May I ask what issues this causes?
I have been running my 940 at 3.5 with my 4 1gig 1066 modules in an Asus Crosshair 1 without any problems. I would like to understand better what the issue is here.
Thanks.

The issue appears when you use the reference clock to overclock your processor. When you raise the reference clock, everything else that is connected to that speed also increases (and specifically, the ram).

It has been shown that processors that have an IMC (integrated memory controller) don't overclock the ram as well when they have lots of stress on them... aka, having all of the DIMM slots full, because it has to put information through 4 of them, rather than just 2.

So you probably havn't had an issue with yours, mostly because you probably used the multiplier to OC your 940 BE. And its not like its a bad thing anyway, its just that you will usually get a higher max RAM oc with only 2 sticks, rather than 4.

Cheers!

laurie · 05-10-09

OK that makes a lot of sense! I clock my 6000 up with the FSB but then of course my 1066 ram is only at about 850.
With the Phenom I did try to up the FSB and it would just blue screen. So yeah I just stuck the multi at 17.5.
Thanks for taking the time to explain it to me

I will be looking for a two stick 4 gig set then!

All the best.

laurie · 05-10-09

Im having trouble.
I have taken 2 of the sticks out so am only running 2 1gig sticks.
I tried to up the FSB whilst leaving everything else stock but the bios halts on det dram every time.
Any ideas?
Ram is set to 1066 on stock volts.
I tried to select 2.1 but the motherboard does not hold it.

HondaGuy · 05-10-09

M4A79 with 7750 here 8Gb of ram running at 1066 here

Cavi · 05-11-09

Quote:

Originally Posted by HondaGuy

M4A79 with 7750 here 8Gb of ram running at 1066 here

I know that with my ASUS mobo I got a BIOS update that was supposed to increase the performance of 1066 RAM, I see you have the similar update for your board as well. This is likely to have helped your cause. Some people are able to work with multiple DIMMs... most are in the boat that have trouble

Also, you aren't even OC'd. I would challenge you to put a decent OC on that Kuma with your RAM settings consistent to what you have displayed... and come back here with some results! Would love to hear feedback on this.

(is that a 3:8 ratio I see?!) Is this DDR2 800 RAM OC'd to 1066?

jimibgood · 05-11-09

Quote:

Originally Posted by laurie

May I ask what issues this causes?
I have been running my 940 at 3.5 with my 4 1gig 1066 modules in an Asus Crosshair 1 without any problems. I would like to understand better what the issue is here.
Thanks.

Nice doggie!

HondaGuy · 05-12-09

Quote:

Originally Posted by Cavi

I know that with my ASUS mobo I got a BIOS update that was supposed to increase the performance of 1066 RAM, I see you have the similar update for your board as well. This is likely to have helped your cause. Some people are able to work with multiple DIMMs... most are in the boat that have trouble

Also, you aren't even OC'd. I would challenge you to put a decent OC on that Kuma with your RAM settings consistent to what you have displayed... and come back here with some results! Would love to hear feedback on this.

(is that a 3:8 ratio I see?!) Is this DDR2 800 RAM OC'd to 1066?

Yes it is 800 ram Overclocked to 1066 I am running 8GB (2GBx4), Ballistix Tracer LED,DDR2 PC2-6400 the red ones....

Here is that 7750 Overclocked @ 3.5, run Super Pi also

Cavi · 05-13-09

ahh yeah, Tracers, beauty D9s

That along with your BIOS update I mentioned earlier was probably your ticket! Awesome!

HondaGuy · 05-13-09

Same ram settings and mobo, just with 955 tho......

Cavi · 06-11-09

bump so people get informed!

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AM2+ CPU Limitation with DDR2 1066 Explained

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