G. Skill Eco - F3-12800CL7D-4GBECO (2Gx2) Sub Timing

[jivenjune]

I'm having a difficult time running this memory at its indicated default XMP specs. In CPUID, the memory is listed at 8-8-7-24 instead of 7-8-7-24.

The memory itself runs fine without any instability, so I'm wagering that my motherboard is just improperly setting the sub timings. Does anyone know what the exact memory specs are--sub timings included?

Thanks.

[GSKILL TECH]

No, it is possible that CPU-Z is just reading it incorrectly. When you enable XMP, what does it show in BIOS? BIOS should always have the correct XMP detection.

Thank you
GSKILL TECH

[jivenjune]

Well, under "Channel A (&B) Timing Settings," the memory reads at its indicated specs.

Cas Lantency Time: 7
tRCD: 8
tRP: 7
tRAS: 24

Under "Advanced A (&B) Timing Control," the memory specs read as follows:

tRC: 40
tRRD: 5
tWTR: 6
tWR: 12
tWTP: 24
tWL: 8
tRFC: 88
tRTP: 6
tFAW: 50
Command Rate (CMD): 2

Under "Channel A (&B) Misc timing Control," the specs are indicated as follows:

IO Latency: 1
Round Trip Latency: 35

The reason I'm weary about my memory running at improper specs is that when I take out any two sticks--it doesn't matter which--and try to set the memory's "Cas Latency Time" manually to "7," it will show up in CPUIZ at its proper XMP profiled specs as 7-8-7-24. However, if if I stick in another stick (again, it doesn't matter which) and try to get both A & B channels to run at 7-8-7-24, the system will reset and indicate that there has been a bad overclock.

I am running the following hardware:

P67a-UD7-B3 Motherboard
Intel Core i5 2500k
(2) EVGA 1GB GTX 460s in SLI
(4x2GB) G. Skill Eco 1600 Cl 7 Memory
Corsair HX 850W Power Supply

[GSKILL TECH]

You may need to raise VDIMM a little to stabilize the memory on that platform.

With regards to sub-timings, they look just fine.

Thank you
GSKILL TECH

[jivenjune]

When you say VDIMM voltage, you're referring to the memory's voltage, correct?

My BIOS lists the following settings that can be adjusted in terms of voltage:

CPU Vcore
QPI/Vtt Voltage
System Agent Voltage
PCH Core
CPU PLL
DRAM Voltage
DRAM Vref.
DRAM Termination
Ch-A Data VRef.
Ch-B Data VRef.
Ch-A Address VRef.
Ch-B Address Vref.

If I tweak the DRAM Voltage from 1.36 (motherboard won't do 1.35) to 1.4v, the BIOS still resets the settings indicating a bad overclock.

[GSKILL TECH]

A higher voltage may be required especially if you have 4 modules installed. This kit can withstand 1.50-1.60V without a problem, so no worries.

Thank you
GSKILL TECH

[jivenjune]

I've boosted the voltages up to 1.6 v, and the system will just hang. I suppose it's not that big of a deal, but it is a bit disappointing considering these modules were highly recommended for their overclock capabilities.

I've noticed, however, that the PCB on the memory is now black instead of green like it was previously. Did G. Skill change the actual memory modules or the company who manufacturers it?

[GSKILL TECH]

Yea, the ECO series just doesn't work as well on the new Sandybridge platforms.

The black PCBs are a newer version. We manufactured the modules, so we changed them.

Thank you
GSKILL TECH

[jivenjune]

Are the actual memory modules different than the previous version that used a green PCB?

Edit: By modules, I'm referring to the row of black chips attached to the PCB. In other words, should I be expecting less overclock head due to a change in the actual chips in comparison to the previous chips attached to the green PCB of the ECO series?

[GSKILL TECH]

No, it is the same, just works better on a different platform like P55.

Thank you
GSKILL TECH