Questions about OC concepts for i7 920

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EternalHour

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Feb 17, 2011
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My system:
Gigabyte GA-EX58-UD5 motherboard w/ F12 BIOS
Core i7 920 D0 Bloomfield CPU
6GB OCZ Gold DDR3-1600 RAM, triple channel
Ultra X3 850-Watt modular PSU w/ 64A on the 12V rail

I have decided that I want to OC my processor to get some better performance and unlock it's full potential. I am very knowledgeable with computers but new at overclocking and am running into some difficulties while trying to follow some of the guides, one in particular: http://www.overclockers.com/3-step-guide-overclock-core-i3-i5-i7/
I've determined that with stock cooling I cannot go higher than 3.0GHz due to temps, which is fine for now. I also noticed that if I increase the VTT voltage like it recommends beyond stock, my system is not stable and will not load Windows completely. It is stable however at stock voltage. Then I run into trouble with the memory. If I set the BCLK to 200MHz, 12X multiplier, and RAM frequency to anything other than 900MHz the system is not stable, with 1.64V or auto. My trouble seems to be voltages but what am I doing wrong?

I also plan on purchasing these for better cooling:
Prolimatech Megahalems Rev.B CPU Cooler
SILVERSTONE FM121 120mm Case Fan
 
200 baseclock and a 12x RAM multiplier will be overclocking your RAM way above its rated spec, 2400MHz on 1600MHz RAM will definitely not POST.

A popular i7 OC for 1600MHz RAM is 200 baseclock, 21x CPU multiplier, and 8x RAM multiplier. That will give you 4.2GHz CPU and 1600MHz RAM clocks.

If you have a lucky chip you should be able to do that on low voltage and stock cooling, though if you want a cheap aftermarket cooler that performs very well try the CoolerMaster Hyper 212+, on sale for $15 some times, will help a lot on temps vs Intel's heatsink. Megahalems is great, a top level cooler along with Noctua NH-D14/Thermalright Silver Arrow.

Voltage wise see how far you can go under 1.4 VCore and 1.35 VTT, I'd keep RAM at its spec if its 1.65v.
 
Thanks for the reply jdof. Until I get the aftermarket cooler and things are stable, I want to shoot for 3.0GHz. I know it's not much. But I am just confused with the memory settings. With my BCLK at 150 and multiplier at 12x (3.0GHz) what can I do to get the RAM to run at 1066 or close to it? I assume it involves setting the divider properly, atleast this is what I remember from overclocking my Opteron. Right now, I can get 900 with the multiplier at x6 or 1200 with the multiplier at x8. Any suggestions are appreciated, I am just trying to learn.
 
EternalHour said:
Thanks for the reply jdof. Until I get the aftermarket cooler and things are stable, I want to shoot for 3.0GHz. I know it's not much. But I am just confused with the memory settings. With my BCLK at 150 and multiplier at 12x (3.0GHz) what can I do to get the RAM to run at 1066 or close to it? I assume it involves setting the divider properly, atleast this is what I remember from overclocking my Opteron. Right now, I can get 900 with the multiplier at x6 or 1200 with the multiplier at x8. Any suggestions are appreciated, I am just trying to learn.
Click to expand...

You want a 5x multi on the RAM with a 150MHz BCLK.

150x5x2=1500MHz. (x2 as it's "double pumped".) It will be under-clocked, but that is fine until you can manage the aforementioned 200x21 with a 4x mulit for 200x4x2=1600MHz. (What I run my 950 rig listed below at.)
 
I don't quite understand 4nic. The default settings for my board, are 21x133=2.8 for the CPU and 8x133=1066 for the memory, with turbo enabled of course. My memory multiplier increases in multiples of 2, 6x being the lowest then the next setting is 8x. Does that makes sense?
So if the BCLK is 20x150=3.0 then I set the memory to 6x150=900 the system is stable, if I set to like 8x150=1200 or anything higher it will not boot. I believe it is the voltage settings but I will have to play around with it some more when I get home. In the mean time anymore suggestions would be great.
 
Hhhm, all my mobos had 3-9 or some such. (Including my last 2 Gigabyte boards, though s775.) I'm surprised the lowest RAM multi is 6. Seems rather limiting. Though admittedly my experience is rather light compared to many here.

The 6x150=900 is actually running at 1800MHz with DDR and the 8x150=1200 would be 2400MHz. That's simply way too much of an OC for the RAM. 1800MHz is not to much of an unreasonable OC, in my opinion. My 1600MHz will do 1800MHz.

You could try these settings instead.

21x140=2940MHz.
6x140x2=1680MHz.

Almost 3GHz and just a slight RAM OC.
 
Little_4nic8er said:
Hhhm, all my mobos had 3-9 or some such. (Including my last 2 Gigabyte boards, though s775.) I'm surprised the lowest RAM multi is 6. Seems rather limiting. Though admittedly my experience is rather light compared to many here.

The 6x150=900 is actually running at 1800MHz with DDR and the 8x150=1200 would be 2400MHz. That's simply way too much of an OC for the RAM. 1800MHz is not to much of an unreasonable OC, in my opinion. My 1600MHz will do 1800MHz.

You could try these settings instead.

21x140=2940MHz.
6x140x2=1680MHz.

Almost 3GHz and just a slight RAM OC.
Click to expand...

Forgive me for my inexperience but I am curious why you are multiplying the RAM frequency x2? All the forum posts I have found and guides are not doing this. For example:
The defaults are 133x21=2.8 then RAM at 133x8=1066, POST shows 1066 as the RAM frequency. Other settings I have found for the i7 are 190x21=3.99 then RAM @ 190x8=1520 which is obviously a slight underclock. If I use the settings you suggested POST shows my RAM frequency as 840MHz, not 1680MHz.
 
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21x200 x8 RAM multi is a round number 1600MHz RAM OC with 4.2GHz CPU
21x160 x10 RAM multi is a lower CPU clocked round number 1600MHz RAM OC with 3.3GHz CPU

You cant POST above 900MHz RAM? I'd suspect the OCZ RAM is misconfigured or defective. Have you tried removing and reseating the RAM sticks?

Are you setting the timings manually to the the RAM's spec? Something like 8-8-8-24?

Try to set vDIMM to 1.65v and manually set conservative RAM timings at 9-9-9-24.
Try stock 21x133 x12 RAM multi.
Make sure the Uncore multiplier is on Auto or manually set to x24(it needs to be at least double the given RAM multiplier)
Try 1.3v VCore and 1.3v VTT.

Boot and test your memory with the latest memtest86+ from memtest.org for at least an hour or two and see if it throws errors at those settings.
 
jdof said:
21x200 x8 RAM multi is a round number 1600MHz RAM OC with 4.2GHz CPU
21x160 x10 RAM multi is a lower CPU clocked round number 1600MHz RAM OC with 3.3GHz CPU

You cant POST above 900MHz RAM? I'd suspect the OCZ RAM is misconfigured or defective. Have you tried removing and reseating the RAM sticks?

Are you setting the timings manually to the the RAM's spec? Something like 8-8-8-24?

Try to set vDIMM to 1.65v and manually set conservative RAM timings at 9-9-9-24.
Try stock 21x133 x12 RAM multi.
Make sure the Uncore multiplier is on Auto or manually set to x24(it needs to be at least double the given RAM multiplier)
Try 1.3v VCore and 1.3v VTT.

Boot and test your memory with the latest memtest86+ from memtest.org for at least an hour or two and see if it throws errors at those settings.
Click to expand...

Thanks for the reply jdof. After digging deeper into the settings I had found previously, and finding info on the OCZ forum I figured out the issue. It was in fact the Uncore holding me back. I remember seeing that it needed to be set at x2 the RAM speed. I looked at it and it was defaulted at 2400 something, simply changed it to 3000. That also explains why I couldn't get past 900MHz. I used 20x150=3GHz then the RAM @ 10x150=1500GHz with 8-8-8-24 1T for the timings. I then upped the voltages to DRAM 1.64 and QPI to 1.34 and all this did the trick. I also disabled turbo. You were right on the money. I look forward to getting the new CPU cooler so I can really start to unlock the potential of my CPU. Thanks for all the input everyone!
 
EternalHour said:
Forgive me for my inexperience but I am curious why you are multiplying the RAM frequency x2? All the forum posts I have found and guides are not doing this.
Click to expand...

DDR stands for Double Data Rate, so you double the clock speed.

My RAM for example is running 200 BCLK with a x4 multi for 800MHz. Then you "double pump" with DDR and you get the rated speed of 1600MHz.

Double data rate
 
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