Ram:cpu

[Ryan_Fpv]

Does increasing the DRAM:FSB ratio increase the temperatures of your CPU? Or does changing the DRAM Frequency increase your CPU temperatures?

My mate keeps complaining that his Corsair Dominator Ram only runs at 1066mhz instead of the 1866mhz that it is supposed to run at. I keep telling him to go into the bios and change the DRAM:FSB ratio (or the DRAM Frequency since his Asus bios doesn't seem to have DRAM:FSB ratio settings), however he refuses to do it because he says changing it puts his CPU temperature at 60*C on idle*. (*that was when he used the XMP setting which increases both memory frequency and CPU bclk frequency, however he still claims he can't change his memory frequency without it putting his CPU temps into dangerous zones)

I decided to run a little test with my PC to see if CPU temps do increase when the memory frequency is increased. I'm using the rig in my sig below, CPU running @ 21x 166Mhz bclk with CoolerMaster Hyper TX3 heatsink.

Here are the results (idle temps):

DRAM @1660Mhz (DRAM:FSB @ 10:2)
CPU 30 °C
Core #1 42 °C
Core #2 36 °C
Core #3 40 °C
Core #4 36 °C

DIMM Voltage: 1.62V


DRAM @1328Mhz (DRAM:FSB @ 8:2)
CPU 30 °C
Core #1 41 °C
Core #2 36 °C
Core #3 40 °C
Core #4 35 °C

DIMM Voltage: 1.57V


DRAM @996Mhz (DRAM:FSB @ 6:2)
CPU 31 °C
Core #1 43 °C
Core #2 38 °C
Core #3 41 °C
Core #4 37 °C

DIMM Voltage: 1.54V


Now, my CPU temps are coming out (relatively) the same. On all ram frequencies CPU core temps were an average of about 65*C during prime95. I'm sure with the voltages up that the RAM itself will be running hotter, but that's not the issue.

So, is it accurate in saying that increasing the DRAM:FSB or Dram Frequency does not increase the CPU temperature?
Or is my friend correct in saying "1866 mhz required more frequency to be pushed through the cpu circuitory motherboard ram and increases the temperature of everything"?

 

[87dtna]

Higher ram clocks puts slightly more load on the internal memory controller in the CPU, which is make a very itty bit amount more heat. But it will barely be noticeable, so yeah he's full of crap and/or doesn't know what he's doing.

 

[Ryan_Fpv]

Haha, that sounds about right. Thanks for the reply.

 

[Hsv_Man]

X.M.P or extreme memory profile will infact produce more heat. As it automatically fiddles with not just memory voltages but also cpu voltages.

 

[Ryan_Fpv]

Yeah... I know... Since I was the one who told you that, and also stated it in my original post.

5/09/2010 1:58:55 AM Ryan Matt Hsv if you change the DRAM:FSB, it won't change the CPU temps whatsoever
5/09/2010 1:59:09 AM Matt Hsv Ryan came back when i went to 1866 and temps were 59* 56 60* 55*
5/09/2010 1:59:19 AM Ryan Matt Hsv how did you set it to 1866?
5/09/2010 1:59:27 AM Matt Hsv Ryan x.m.p
5/09/2010 1:59:59 AM Ryan Matt Hsv in AI overclock tuner?
5/09/2010 2:00:48 AM Ryan Matt Hsv x.m.p overclocks the base clock frequency as well
5/09/2010 2:00:54 AM Ryan Matt Hsv which is why your temps were higher


Then when I told you to set the frequency manually without using XMP, you said you wouldn't do it because of the temps... Which then lead to this thread.

 

[Hsv_Man]

You are forgetting that on an i7 900* series machine the processor works in sync with the ram and therefore bumping it up past intels recommended 1333 mhz will mean of course it is going to need more volts and end up producing more heat.

 

[87dtna]

It works the same way as an I7 800 series too. And no you should not need added voltage to run 1866mhz. The IMC can handle that on all stock volts.

XMP is worthless and stupid. Manually set the CPU voltage. Intel's rspec is actually 1066mhz with the I7 900 series, it's 1333 with the 800 series. I've known tons of people that run well over 2000 MHZ on them.

I7's run extremely hot on the stock cooler. Get a different cooler.

 

[Hsv_Man]

Last night I bumped the frequency up to 1866 mhz it done its thing then came up "overclock failed reset to default values." I then thought ok well i will try 1333mhz I put the frequency in it done its thing and is currently running stable (no blue screens) so far anyway. I do realise I need a new cooler and am currently in the process of acquiring a prolimatech megahalem with 2 scythe fans running a push pull config. This should drop temps atleast 10* possibly upto 15* which i will be very happy with.

Edit: I should mention bumping up the frequency from 1066 Mhz to 1333 Mhz increased cpu core temps 3-5*c.

 

[87dtna]

You probably needed to set the ram voltage to 1.65v. Default on most boards is 1.5v, so at proper speed it will be unstable at only 1.5v.