i5 3570k memory controller vs i7 3770k having some issues.....

kahndale

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May 16, 2012
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This is pretty simple but I had a chance to get an i7 3770k brand new for 229.99 at micro-center over the i5 3570k at 189.99 a 40 dollar difference. So i did and i also bought some Corsair Vengance 2133 (pc 17000 11,11,11,30@1.5v).
I proceeded to install the memory, set the timings and could not get it to work past 1866 @1.65v 9,10,9,29. So took it into my shop today and used an i5 3570k i had in my shop with some Corsair XMS 3 2000 @1.65v 9,10,9,27. Now i know they (the memory) are similar but two different builds need 2 sets of ram, so I started swapping parts.
I could get the i5 3570k to read the 2133 no problems, but the i7 3770k could only run the 2000. Also the Motherboard i am using is a Gigabyte GA-Z77X-UD3H for both builds. I am just wondering why the 3570k reads the ram right but the 3770k does not. I was told that it was because of the cpu's memory controller being overclocked to support the faster speed. I also was told that 1600 is the max speed of most Intel chip memory controllers...
Does anyone have any idea if it is hyperthreading on the i7 holding it back due to heat issues...or if the 1600 is true...im kind of lost and need to be pointed in the right direction...
 
Solution
Agreed, 1600 MHz is supported with either of those two CPU's. It's just luck that the 3570K supported a OC one step higher than the 3570K.

People see the high GHz memory at stores so they "go for it". But what you actually want is 1600 MHz modules with tight timings. Cas 7 dimms would be awesome, but they are expensive.

Use the 3770K with the dimms set to 1600MHz and timings at 8-8-8-24. If it's not stable go up to 9-9-9-28. Hopefully you won't have to run at cas 10, but even then... the difference wouldn't be much.

wdmfiber

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Dec 7, 2012
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Agreed, 1600 MHz is supported with either of those two CPU's. It's just luck that the 3570K supported a OC one step higher than the 3570K.

People see the high GHz memory at stores so they "go for it". But what you actually want is 1600 MHz modules with tight timings. Cas 7 dimms would be awesome, but they are expensive.

Use the 3770K with the dimms set to 1600MHz and timings at 8-8-8-24. If it's not stable go up to 9-9-9-28. Hopefully you won't have to run at cas 10, but even then... the difference wouldn't be much.
 
Solution

kahndale

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May 16, 2012
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sweet that lets me know I was on the right track with the Memory Controller info I was told. Yeah I am going for pure benchmark scores. Right my the machine is running a 4.5GHz with 2000 MHz 9,10,9,27 T2 and the samsung 840 ssd is proving to be a great great drive. I was just wondering if they used a different memory controller between the cpu's or somthing. Thanks for the help guys appreciate it.
 

ericjohn004

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Oct 26, 2012
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I have a 3570k and I run some G. Skill Ares (Blue) 2133Mhz 9-11-10-28 RAM. And it seems to run at 2133Mhz perfectly. It brought my CPU scores up enough that I get scores like I'm at 4.7Ghz when I'm only at 4.6Ghz. Now I can keep my CPU at a cooler overclock and get the same performance.

So I'd say the difference in performance between 1600Mhz memory and 2133Mhz memory is about the difference of a .1Ghz overclock. It doesn't seem like much, but to cost between 2133 and 1600 isn't too much either.
 

wdmfiber

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For getting the best benchmark score, usually faster memory with looser timings score worse than 1600 MHz memory with a tight timing. Because... simply put, the high MHz speed is crippled by the slow timings. However, if you are really running at 2133Mhz with 9-11-10-28 timings(and I believe you) then you got a good CPU and batch of memory.

I just roughly calculated the latency such a system would have(in nanoseconds) and your score is impressive.

But I think that would be hard to duplicate on another system, unless someone was in a position to "bin test" some product and keep the best samples. Anyone reading this and wants fast ram should just get 1600 MHz dimms with 8-8-8-24 timings. 7-8-8-24 dimms would be awesome, but they are pricey(as mentioned earlier).