Corsair Vengeance not running correct frequency

mike12345567

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May 8, 2011
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Ok so basically i've just finished my first major system build (i5 2500K, GigaByte P67 UD4, Radeon 6970, 8GB Corsair Vengeance 1866Mhz) and its been a bit of a headache so far but its all starting to get sorted.
At the moment I only have the stock Intel cooling unit on my CPU, I had an H70 but faulty pump means it got sent away.
I have just installed CPU-Z as I've heard this is the best way to check everything and it is saying DRAM frequency of 665Mhz (doubled to be around 1333Mhz, NOT the 1866Mhz labelled on the box) I'm just wondering if the system has slowed the RAM down due to it not functioning properly or something like that.
I know I can set it up in the BIOS, something in there is set to 13.33 and theres an option for 18.66, which I assume gives the RAMs speed of 1866Mhz. I just want to know if I set it up to 18.66 to get the RAMs supposed true speed will the modules crash/heat up too much or something? They are running at the 1.5V they are supposed to require.
 
Welcome to Tom's Forum! :)

Easy:
The simplest is to set the XMP in the BIOS:
Extreme Memory Profile (X.M.P.) -> Profile1

Manual:
Assuming: 1866 MHz 9-10-9-27-2N http://www.corsair.com/vengeance-8gb-dual-channel-ddr3-memory-kit-cmz8gx3m2a1866c9.html

If the plan is to OC then I'd suggest Manually setting the RAM:
Advanced Memory Settings /Enter
System Memory Multiplier -> 18.66
DRAM Timing Selectable -> Quick
CAS Latency Time -> 9
tRCD -> 10
tRP -> 9
tRAS -> 27
-
Command Rate (CMD) -> 2
 

mike12345567

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thank you jaquith, that sorta makes sense but is it actually an overclock considering that the RAM is designed to produce 1866Mhz?
From CPU-Z the current stuff is all as you say it is, I went to SPD tag and it says XMP-1866 then everything else is set, and it is saying 933Mhz but the reading is still overall 1333Mhz, does the XMP-1866 in CPU-Z have anything to do with it?
 
I meant if you're OC the CPU and obviously if you're 'OC the RAM' {beyond Rated} then in either case use manual.

OC RAM e.g. 2133 MHz or faster CAS Timings:

Frequency OC:
System Memory Multiplier -> 21.33
DRAM Timing Selectable -> Quick
CAS Latency Time -> 9
tRCD -> 10
tRP -> 9
tRAS -> 27
-
Command Rate (CMD) -> 2
DRAM Voltage -> 1.65

OR

CAS OC:
System Memory Multiplier -> 18.66
DRAM Timing Selectable -> Quick
CAS Latency Time -> 8 or 7
tRCD -> 9 or 10
tRP -> 8 or 7
tRAS -> 24 or 27
-
Command Rate (CMD) -> 2
DRAM Voltage -> 1.65

Frequency & CAS OC:
System Memory Multiplier -> 21.33
DRAM Timing Selectable -> Quick
CAS Latency Time -> 8 or 7
tRCD -> 9 or 10
tRP -> 8 or 7
tRAS -> 24 or 27
-
Command Rate (CMD) -> 2
DRAM Voltage -> 1.65
 

mike12345567

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Right ok, so I need to input these settings if I am planning to overclock my CPU, but if I am running CPU stock what do I do?
Also does the RAM need to be set to a higher voltage for 1866Mhz? it is rated at 1.5V but you have listed 1.65V for a multplier of 18.66.

Sorry for noob questions, I don't really understand all RAM settings, just what it is.
 
No, look very carefully - no accident - the second post from me includes settings IF you OC the RAM and if you do then 9/10 you'll also need to increase the DRAM Voltage above 1.50v. The FIRST post of mine is for Rated Frequency, CAS Timings and ignoring DRAM Voltage. IMO - you might want to set the DRAM Voltage -> 1.50v in the TOP set - Auto can over-volt with OC the CPU.

Again, STOCK:
Easy:
The simplest is to set the XMP in the BIOS:
Extreme Memory Profile (X.M.P.) -> Profile1

Manual:
Assuming: 1866 MHz 9-10-9-27-2N http://www.corsair.com/vengeance-8 [...] 866c9.html

If the plan is to OC then I'd suggest Manually setting the RAM:
Advanced Memory Settings /Enter
System Memory Multiplier -> 18.66
DRAM Timing Selectable -> Quick
CAS Latency Time -> 9
tRCD -> 10
tRP -> 9
tRAS -> 27
-
Command Rate (CMD) -> 2

DRAM Voltage -> 1.50v
 

mike12345567

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May 8, 2011
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18,510



Ok sorry jaquith, I get what you mean now, and thank you, I followed your easy instructions for stock and that got it working, thank you for sticking in there, it takes me a while to grasp things... Well again thank you, My RAM is now working properly and once I overclock I will follow your OC instructions to make sure my modules stay the way they are.
 
Glad to hear, enjoy. :)

Sometimes XMP fails which is why I post both ways. Also, even more frequently 4x__GB doesn't work as XMP. So you're set now with a slew of options and 2 ways to achieve Stock. I know too much might have confused you, but now you know and understand more than most.