Issue w/ F3-16000CL6T-6GBPID (not seeing 6GB)

[Psychor]

Hardware: i7 920 D0, EVGA x58 Classified 760, 3x2GB GSKILL F3-16000CL6T-6GBPID. Both the i7 and EVGA are water cooled.

I'm having a hell of a time getting all 6GB of my RAM to show up either in the BIOS or in Windows 7. It seems that sometimes only 4GB shows will up and others times only 2GB will show up. It all depends on my BIOS settings for the memory.

I'm able to run my i7 @ 4GHz (20x191 -> 21x191 actual) rock solid (50 passes of LinX) if I leave my memory settings set to default. Of course at default the RAM isn't being used to its fullest but it's good for testing my system stability. However, the second I try and set it my memory to 1913 MHz (the closest I can get to 2000 MHz with 191) @ 6-9-6 I can't see all 6GB. If I set my timings higher than 6-9-6 (e.g., 7-9-7 or 8-8-8) I usually can see all my RAM. Why can't I run the RAM at 6-9-6 @ 1913 MHz.

Thanks.

[Psychor]

So why do I have to go to 7-8-7 to get access to all my RAM? Let me give you an example.

With these settings my system sees 2GB/6GB...



With these settings my system sees 4GB/6GB...



With these settings my system sees 6GB/6GB...

[Roylion15]

For me the QPI voltage is very high at 1,5 V that generate more heat and give signal saturation thus no recognize always all the modules.

Try lower values , like 1,38 or 1,42 V max, lower is better but make some tests with memtest and prime 95 to avoid any errors.

My experience with O/C settings on EVGA cards is not great but well with ASUS cards.

Why is QPI voltage set to a so high value ?.

Sometimes it's very difficult to reach 2000 with very low timings.
Try 1833 CL6 by example

[GSKILL TECH]

Roylion15 is correct, which is why finding the precise CPU VTT Voltage is necessary. This is the most difficult part about configuring high performance memory. Too low or too high can cause problems.

Thank you
GSKILL TECH

[Psychor]

Roylion15 is correct, which is why finding the precise CPU VTT Voltage is necessary. This is the most difficult part about configuring high performance memory. Too low or too high can cause problems.

Thank you
GSKILL TECH

I will play with the CPU VTT but that doesn't explain why the different timings with the same CPU VTT in my 2nd post result in different amounts of memory showing up does it?

[GSKILL TECH]

More aggressive latency, more voltage needed. Not enough voltage, drop a channel. Drop a channel, lose memory capacity GBs.

Check the sticky in the DDR3 main page for other possible causes.

Thank you
GSKILL TECH

[Psychor]

More aggressive latency, more voltage needed. Not enough voltage, drop a channel. Drop a channel, lose memory capacity GBs.

Check the sticky in the DDR3 main page for other possible causes.

Thank you
GSKILL TECH

I've tried VCORE up to 1.4v, VTT +250 through 350mV, QPI PLL VCORE up to 1.3-1.5v, DIMM Voltage 1.65. With the memory at 6-9-6-24 @ 1913 Mhz my system only sees 4GB/6GB. I don't see how much more voltage these sticks could need. I'm able to run my i7 920 @ 4GHz rock solid with considerably LESS VCORE and VTT.

[Roylion15]

For 2000 Mhz DDR3 and cpu @ 4Ghz with 7 920 D0

CPU PLL must be set min @ 1,8V > 1,82V
VCORE leave @1,35 V
try QPI 1,4V

[Psychor]

For 2000 Mhz DDR3 and cpu @ 4Ghz with 7 920 D0

CPU PLL must be set min @ 1,8V > 1,82V
VCORE leave @1,35 V
try QPI 1,4V

No, even at 1913 MHz I can't get 6GB to show up unless I loosen the timings.

[Psychor]

I reset my CMOS and set the memory to the XMP profile and even that doesn't seem to work. I also tried tweaked the voltages afterwords. This memory is going to be the end of me. I hate to return it but my sanity is worth more.

[GSKILL TECH]

Please send them in for replacements to see if the new kit solves the problem.

Thank you
GSKILL TECH

[Psychor]

Please send them in for replacements to see if the new kit solves the problem.

Thank you
GSKILL TECH

How do I go about doing this? Can I have the memory cross shipped or do I have to first send back my old memory?

Thank you.

[Tradesman]

You'll want to contact the RMA dept at rma@gskillusa.com more info can be found at:

http://www.gskill.com/rma.php