Not quite understanding "DRAM and QPI Freq" while overclocking

Hey guys,

I joined the forum and received lots of help I'm guessing almost a year ago. (Awesome community!) Well I decided to stop overclocking because I stopped playing PC games and felt if it's not broken why fix it (no need to stress the cpu and memory). So I recently started to get back into doing some PC gaming and here is where I'm at...

My current setup is this:

BCLK 167
CPU Voltage 1.28V
DRAM Voltage 1.60
DRAM Freq is at 1336 (Although my memory maxes out at 1333mhz)

I am currently running Prime 95 (load testing) and so far the max temp I've hit is 71c. Now the confusion with the DRAM freq is what's killing me. I'm running cpu-z and although I have it set to 1336mhz it's hit a max of 670mhz. I checked my original thread and someone said to mess with the QPI voltage/freq, what exactly would that be doing? I'm not trying to do a crazy OC.

Processor: Intel Core i5 750 Lynnfield (2.67ghz) and it's running at 3349mhz.

I also forgot to mention that I have the enhanced speedstep(i think that's what it's called) disabled and i'm still seeing the CPU dip to 1.5ghz while running the load test...i thought by disabling that it should prevent that. Any advice on that is greatly appreciated as well.


Thanks for the help and advice. (trying to get back into this is just confusing me hehe)

to OCForums! You're off to a good start

The RAM's rated speed of 1333MHz is its effective speed including the Double Data Rate (DDR). The RAM's actual speed is half of the effective, so 667MHz shown in CPU-Z.

QPI/Vtt voltage is the IMC voltage, so it may need increasing as bclk and/or RAM frequency is increased.

You also need to disable C1E to stop the CPU from downclocking when idle.

Also, in my signature is an i7 overclocking guide you should look at. It gives some solid high level explanations of it, and the overclocking process as well.

Thank you! I'll take a look at it right now. So far though it seems to be running stable other than that random downclocking.

So i'm on my laptop right now and have the bios open on my desktop and I do not see an option to disable "C1E." From my understanding the Intel SpeedStep Tech would be the equivalent which was what I would disable to prevent the dip on clock speed. It says right in the bios "Enabled: CPU Speed controlled by Operating system. Disabled: Default CPU speed." So what would still cause the dipping in clock speed?

I think i've run into a snag...I changed the IMC rating from auto to 1.15 ranges from 1.10-1.20 (only thing i've changed since my original post) I'm 30min into it and Core 3 out of 4 has stopped working completely and only 50% of my RAM is in use during the load test instead of 67%...did I just break my processor???

The C1E Support option is located in the Advanced menu. Also disable Intel C-State Tech, located directly under Intel SpeedStep Tech in the same menu.

In the "Advanced" tab in BIOS go to "CPU Configuration" and C1E and Speedstep are there, make sure they are disabled. Also, C-State Tech may need disabling too.

So I am kind of worried now about the processor, I changed the settings back to what I originally overclocked which seemed stable, Core 3 started up and than failed again. Here is a pic

I highly doubt something is wrong with the CPU. All your voltages are in check and you have a small bclk OC.

How long did you stress it when it "seemed stable" earlier?

Thats usually a vcore thing when one core drops and the others keep going. Reset back to stock and start over with proper overclocking methodolgies and go from there is my suggestion at this point.

I also doubt anything is wrong with the CPU as well.

MattNo5ss said:

I highly doubt something is wrong with the CPU. All your voltages are in check and you have a small bclk OC.

How long did you stress it when it "seemed stable" earlier?

Click to expand...

Total of 35min if that, i'm going to go back to default and start fresh

For 24/7 use, you should stress P95 for a few hours at least. I use LinX b/c I'm impatient, it just gets the temps way up there.

Starting fresh and trying to follow Miah's guide wouldn't be a bad idea.