FSB:DRAM Ratio

[Kayko]

Hello, I'm really hoping someone can give me an idea on what to do here.

I understand that the question does come up a bunch, but in my searching, I just can't seem to find an answer.

My system:
i7 920
Asus P6t
Mushkin 3 x 2GB PC-12800 1600mhz DDR3 ram

I have a slight idea on how to Overclock and I'm trying to get the most out of this system as I can.

With stock settings, I'm seeing a FSBram being 6:1, This can't be good. I understand were it comes from (1/2 1600mhz) ram and 133mhz clock. Though anything passed this is a mystery to get.

My multiplier can go from x13 to x21 and I havn't yet really played with moving the FSP up 1 by 1, but I can get it around 200ish on a X17 clock, about 185 with a x19, and about 170 with a x21 multiplier. It seems that with a higher multiplier, I can get higher CPU speeds, but thats the problem, the higher the multiplier, the worse the FSBram ratio is.

Is there any way I can fix this and get the ratio closer to 1:1? Or am I just reading the numbers wrong?
Most of the info I can find is either outdated and involves DDR2, AMD based, or skims over the question asking for test this and test that then runs off into space.

Thanks for any help anyone can provide. I'm geussing I ignore it all together and search for whatever gets the best readings through stability tests.

 

[henydiah]

better ratio in 1333 3:10 u can get max Low CAS maybe 7-7-7-21 stable
VDIM Max 1.65 V best for performance DDR3

 

[Andon48]

You should be able to change your memory ratio somewhere in your bios. 6:1 would be the stock ratio, 6 X 133 Bclock = 800 mhz and you double it since it is DDR memory. (that is the same for DDR3 and DDR2) That gives you your DDR3 1600 speed. You need to lower the ratio as you increase the Bclock. To keep the 1600 mhz frequency you would need a ratio of 4:1 with a bclock of 200 mhz. 200 mhz X 4 = 800 mhz and then you double it to get 1600. You just need to find the best multiplier available for the Bclock you want to run at. That's the beauty of an unlocked CPU multiplier, you can change it to get the bclock you want to make the ram run at the right speed. It's all about the Bclock and the memory ratio.

 

[sportsfanboy]

If your not overclocking the 1 to 6 ratio is fine. The days of running 1:1 are gone and over stated as a matter of importance. Different FSB/baseclock to ram ratio's will run slightly different as far as speed and latency goes. That said it is unlikely you will feel the difference at the same frequency, and will only really see a big difference in synthetic bench marks.

Feel free to tweak and try to get the most out of it, hell I do, but it isn't absolutely necessary.

 

[Andon48]

I'd just try to run your ram as close to it's rated speed as possible for stability's sake. Like sportsfanboy said, DDR3 ram speed doesn't really make that much of a difference. Just get your proc. to where you want it, adjust the memory ratio, and make sure it passes memtest 86+. You can spend all day tweaking the memory and only gain like a 2% performance boost.

 

[Kayko]

Thanks for all the help. Just knowing that I shouldn't worry about the ratio helped out a bunch.
Now running X19 multiplier with a 200 clock giving me 3.8 speeds.
In the process of running a stress test (AIDA64, formally known as Everest) and holding steady running stress on CPU, FPU, Cache, and Memory with CPU temps averaging aroudn 58.7c over 16 minutes currently.

Since AIDA64 does a stress test on system memory, should I still get Memtest?

edit: I would at some point like to get some more out of the memory eventually. The Memory I recently got was the Mushkin redline (6-8-6-24) All I really know is that a lower first number = faster (in general terms) I've read about raising the timings in order to allow speed above 1600Mhz, but have to spend some more time researching that before I make any changes.

 

[Andon48]

According to all of the reviews I've seen the best performance will come from 1333mhz with the lowest stable timings.