M4A89GTD Pro/USB3 F3-10666CL7D-8GBXH

[cossak2007]

Just received my 4 sticks of F3-10666CL7D-8GBXH memory....consecutive serial numbers
Motherboard Asus M4A89GTD Pro/USB3
Phenom II X4 965 Black Edition processor

Motherboard recognizes only 8 gigs out of the 16 g installed.
Windows 7 Pro x64 recognizes all 16 gigs but says only 8gigs are usable.
Timings set at 7-7-7-21
No errors or problems.

Is there a setting I am missing to get the MB to recognize all of the 16 gigs of memory installed?
Suggestions ?
Return the memory sticks back to Newegg for refund or replacement?
If replaced, what model of memory would you suggest?

[Tradesman]

First ensure all sticks are firmly seated, might want to check the CPU/Socket for thermal compound, dust, etc as well as bent pins (a very common cause), Can also go into MSCONFIG, go to Boot tab, ADVANCED tab, and make sure MX MEM is unchecked, can also take a look at this:

http://www.gskill.us/forum/showthread.php?t=5136

Though I've found it's normally one of the three I mentioned

[cossak2007]

Resolved and Thanks to Trademan

Replaced the CPU with AMD FX 6100 and all 16 gig memory recognized immediately on boot up.
Thought it was the MB and wasn't aware of the role of the CPU with memory chips.

Thx for your help Tradesman, for steering me in the direction of the CPU.
Terry Shekalo

[Tradesman]

No problem, glad to help, keep in touch

[cossak2007]

Just out of curiosity, in my case, what does the CPU have to do with the memory sticks?
Thanks
Terry

[Tradesman]

To basically use DRAM (especially in large quantities), with AMD that's generally 8GB or better, you need a CPU that is powerful enough for it's MC (memory controller) to drive all the sticks. Most AMD CPUs are really designed for 1 stick per channel (you have 2), the FX 6100 is suppose to run up to 1 per channel at 1866 and has a stronger MC than the 965, which should have been able to drive all four sticks, but their may have needed voltage adjustments, might have had bent pins where it was inserted in the socket, etc

[cossak2007]

Thanks again Gman

[Tradesman]

Gman?, no not with the FBI though I do get involved in Flaky BSOD Investigations

[cossak2007]

LOL >> If I was going to apply voltage changes to the AMD 965 CPU to get it to recognize the 16 g of memory, where would I start as I am a newbie at this? The AMD 965 runs cooler and faster than the fx-6100
Terry

[Tradesman]

Prob start with + .08 to CPU/NB voltage and then maybe + .05 to DRAM

[cossak2007]

Still no luck with the 965 even with higher voltages.
Newbie question. How can Windows see the 16 gigs (8 gigs unusable ) but not the BIOS?
Maybe not possible to pair the memory with this CPU and go back to the slower FX-6100?
Terry

[Tradesman]

The BIOS should see it all...don't remember if I asked but do you have the latest BIOS? When changing the CPU did you check for bent or broken pins, that could cause the problem, could also be a defective CPU, which I'm sort of leaning to now sine the other CPU is fine. Maybe the MC in the CPU, which is why I ask about pins, that is fairly common

[cossak2007]

Reflashed the latest BIOS.
No pins bent. Slight curve to some of the pins that were previously straightened with architech lead pencil but no problems going gently into the CPU socket.

[cossak2007]

I can send your snapshots of CPUZ specs of the memory and cpu if you think it will help.
Appreciate your assistance Tman.

[Tradesman]

As an experiment with the 965, try the sticks at stock timings, DRAM voltage at 1.53, CR at 2N, raise the CPU/nb voltage to 1.2 and the CP-NB freq to 2300, if the BIOS still doesn't see the DRAM then I think the MC is going south