Asus p7p55d+f3 12800cl9s

[nch]

First of all, my PC is based on:
_ASUS P7P55D with the latest BIOS version.
_intel i7 870@2.93Ghz. I don't overclock, all is clean.
_4GB (2*F3-12800CL9-2GBRL), XMP mode. My problem is with 2*F3-12800CL9S-4GBRL.

All works fine. I would like to install 8GB of RAM. So I bought 2*F3-12800CL9S-4GBRL. I check that this DRAM are compatible with my motherboard (http://www.gskill.com/products.php?index=239) . Unfortunately, it seems not to work.

I read some thread on this forum and others...
There is a button called "RAM_OK" on the motherboard to detect the "best" settings of the RAM. I dosen't work. I try different bank A_1 B_1, A_2 B_2, and only one RAM on each bank, the computer doesn't boot. I try the 2*4GB alone, with and without the 2 old 2*2GB. It don't boot.

When I boot with the old 2*2GB, I can run the boot. So, I try different settings in the BIOS. But it don't boot.

What can I do? I'm working with my computer with the old 2*F3-12800CL9-2GBRL. I need my computer (math computing/formal calculus) and I appreciate to have more RAM. The 8GB cost approximately 50 euros, I hope it's not for nothing...

Please help me.

Cordialy!

nch

[Tradesman]

Check that you have the latest BIOS, then try only with the new sticks in the primary slots (believe 1-3 from CPU), may be a bIOS issue

[nch]

As said in the message, I try with the latest versions of the bios (v2003 and v2101(beta)) ans the two channels A_1 B_1 (the blue one) and A_2 B_2 (the black one).

[Tradesman]

Have you run memtest on each stick individually to see if you may have gotten a bad stick? Could also be a problem that the two sticks don't want to play together, Could try raising the DRAM voltage + .05 and/or raising the (I believe on your board) the QPI/VTT (Memory controller ) voltage

[nch]

Thanks four your answer, and I'm sorry for my bad english, but I can't run a memtest : my computer doesn't boot with the new memory stick. Of course, I boot (only) with the old one.
The "mem_ok" switch of my P7P55D flash but after few minutes, nothing happend. The manuel of the mobo says that it mght take about 30 seconds.

I'll try to up the voltage of the memory sticks, but they must work at 1.5V. I don'T want to play the apprentice sorcelor and brun my PC. I won't try more than 1.55V. Is it enough?

In my opinion, the memory sticks are not compatible with my modo (even if your site says it runs with p7p55d) or the two sticks are don't work.

Thank you for your answer.

[Tradesman]

Start with only a single 4 GB stick and see what happens, may want to up DRAM voltage to 1.5, unless something wrong with a stick then they should work fine, with 1 stick can try running Memtest, then try on the other stick by itself

[nch]

Well, after some new test, I can boot with the 2*4GB. To do this, I boot with the old 2*2GB sticks, set the mobo with XMP profile, add +0.5V and reboot after replace the 2*2Gb by the 2*4 GB. Note that the timing are the same and the sticks need the XMP profile. The 8GB was not recognize at the first boot (Windows 7 says 4GB (8GB installed) )). I don't know why it works now.

Despite the same timing of the 2GB and 4GB sticks, the XMP profile and the +0.5V, I can't boot with 2*2GB+2*4GB.

The Asus's "Mem_Ok" technology doesn't work with this sticks (2GB or 4GB).

Cordialy,

nch

[Tradesman]

Since they came as single sticks they may not be fully compatible, and then trying to mix the 4GB with the 2GB sticks can also be a problem, would suggest copying all your current setting, that it now works at, and then if you want to try adding the 2GB sticks you'll have to add DRAM voltage and additional QPI/VTT voltage, in this instance may also have to raise the vCore a minimal amount

[Ergall]

Hi,

I had the same problem with the P7P55D asus. Only one stick was recognized by the motherboard (only 4GB instead of 8GB).
I solved my problem with XMP BIOS configuration and changing the RAM slots. In the Userguide, we must use slot A1 and B1 but it didn't works. By using slot B1 and B2 (A1 and A2 are empty), all my RAM was detected and used by the motherboard.

As we have a lot of post on this subject, I post my solution. I hope it will be helpful.

Have a nice day.