ASUS P8Z77 V Pro sees only half the RAM

[Lyzard]

I have a very strange problem with my ASUS P8Z77 V Pro where it now see's half the memory installed.

I turned my computer on a couple of days ago and the POST said Overclock failed, press F1 to set BIOS... What's weird about that was that my computer wasn't overclocked. I only set the RAM to run at 1600MHz in the BIOS. I built this PC in mid-July and it's been running perfectly fine since then, with all of the RAM usable.

I've tried all of the troubleshooting steps I know since the problem began:
1) I reset the BIOS to the optimized defaults but it still only saw 8 GB of RAM (still dual channel tho)
2) I reseated all of the RAM sticks and tried different combinations. Usually I have 1 of each F3-12800CL9-4GBXL on slot 1 of each channel and 1 of each GSkill F3-17000CL11-4GBXL in slot 2 of each channel. I flipped these but the problem continued. I also tried putting all F3-17000CL11-4GBXL on channel 1 and all 12800CL9-4GBXL on channel 2 and vice-versa but the same thing happened.
3) I cleared the BIOS by unplugging the PC and pulling the battery and letting the computer sit for 15 minutes but when I booted it still only saw 8 GB of RAM
4) I upgraded the BIOS to 0906 to 1610 to see if it would fix the problem but it didn't. I also reset it to the optimized defaults and pulled the battery for 15 minutes with no positive results.
5) I tried each dual channel kit by itself but both of them work fine. Each got through at least 3 passes of Memtest86 4.0a with out any errors. But if I tried will all sticks in the computer MemTest would still only see 8GB of RAM. I also tried booting Ubuntu 12.04 and it also sees only 8GB of RAM.
6) What makes this even weirder is when I boot into Windows, Computer properties says 8GB of RAM (7.46GB usable). I am guessing somehow the iGPU got activated but GPUz doesn't see it and I can't find any options for it under the BIOS. Even under the GPU configuration screen, the only options are Auto, PCIE and PCI. I get no video if I remove my Radeon and plug directly into the motherboard DVI port.
7) CPUz also reports all of the RAM and it can see each stick of RAM under the SPD tab. Windows can't tho and I don't know why. I checked under the DRAM timing controls and both DIMMs on each channel are enabled. Also, the SPD View utility in the BIOS can see all of the RAM sticks.
8) Back in Windows, I even tried the msconfig → boot → advanced options → Use Maximum Memory but that did nothing.

At this point, I have no idea what's wrong with my computer. I am going to try testing each ram stick individually but that will take a while. Unfortunately I don't have another DDR3 computer at the moment to test the RAM on.

If anyone has encountered this problem before, please let me know what other steps I can take to fix it.

Computer Specs:
CPU - Core i5 3570K
MB - ASUS P8Z77 V Pro
RAM - 16 GB (Now only 8GB usable) running at 1600MHz
*-- 2x GSkill F3-12800CL9-4GBXL
*-- 2x GSkill F3-17000CL11-4GBXL
Video - XFX Radeon HD 5770
OS - Windows 7 Enterprise 64bit

CPU-z:

Windows:

 

[Stephen.]

The CPU-Z can detect 16GB as i see but how comes it states that they are currently running 670.2 (1340) default should be 667/666.5 (1333).

So as i can see there is a slight overclock.

When you go into BIOS does it show all 16GB? or just 8GB with all the chips installed?

 

[jagd]

I though maybe mixed memory speed until i saw this on the web from junejuly
''The latest P77 bios (1206 for me) is an absolute disaster. Only 8 of 16GB RAM showing for many, del to get in bios doesnt work (have to use the num pad del) PCIe 3 issues etc. You really should rollback. ''

Motherboard talked about was ASUS P8Z77 V LX but im 99% positive they share same memory settings at bios .
Which bios you are using now ?can you update bios ? Asus bios update needed done carefully ,any friend can help to you?

Also look here http://vip.asus.com/forum/topic.aspx?board_id=1&model=P8Z77-V+PRO&SLanguage=en-us

 

[Lyzard]

When I go into the BIOS, the EZ mode screen only shows 8192 MB of RAM but if I got into the ASUS SPD Information under the Tools Tab, it can see all 4 DIMMs populated with 4GB sticks. In other words, the BIOS detects 16GB or RAM but can only use/address 8GB of them.

I basically reset the BIOS to the Optimized Defaults and that's the RAM speed it configured to automatically. I did go into the BIOS and change the timings to 11-11-11-30 but that had no effect.

I updated the BIOS to version 1616 already, which is the latest version, after this problem started. It didn't help. I just saw that they released version 1708 today. Great! I don't think I'm gonna upgrade just yet tho. It doesn't show memory compatibility improvements.

 

[Stephen.]

I basically reset the BIOS to the Optimized Defaults and that's the RAM speed it configured to automatically. I did go into the BIOS and change the timings to 11-11-11-30 but that had no effect.

Just try loading Default not Optimized Default

2x GSkill F3-12800CL9-4GBXL is stated to run 9.9.9.24 @ 1600MHz

2x GSkill F3-17000CL11-4GBXL is stated to run 11.11.11.30 @ 2133MHz

So the timing you set will work for the GSkill F3-17000CL11 kit/sticks, probably will not work for GSkill F3-12800CL9.

 

[Stephen.]

Try clearing CMOS

 

[drdeathx]

Check for bent pins on the socket or you have a bad IMC. I had this issue with a board about a month ago and 1 pin was a little out of whack. I took a needle and propped it up and bingo, Liftoff.

 

[Lyzard]

There's no defaults or failsafe defaults option on the BIOS, just optimized defaults. I already tried resetting the BIOS using the pins on the motherboard. That was one of the first things I did before I tried pulling the CMOS battery.

The 11-11-11-30 timings will work for the 12800CL9-4GBXL sticks. These timings are slower then that kit is designed work when running at 1600MHz so that wouldn't cause a problem. Plus I had both kits running a 9-9-9-24 1600MHz 1.5V for 4 months without issue, so I don't think there's a problem with the timings.

I didn't think about a bent pin issue. I'll check that when I change the RAM for the next batch of MemTest tests.

Thanks everyone for your help.

 

[Lyzard]

New RAM same problem

So I bought a Dual Channel 4 stick kit during Black Friday to see if it'll fix the issue. A Corsair Vengeance 16GB DDR3 1600MHz (P/N: CMZ16GX3M4A1600C9B). Newegg Link: www.newegg.com/Product/Product.aspx?Item=N82E16820145347

It did not fix the problem. My computer still only sees 8GB or RAM and Windows can only use 7.46GB.

I tested this RAM, 2 sticks at a time, using Memtest86 4.0a for 3+ passes and all of them tested good.

The RAM is running at 1600MHz and default timings using the XMS settings. I reset to the BIOS defaults when I installed the RAM but it still showed 8GB. The BIOS still only saw 8GB or RAM when I switched to the XMS settings.

Also, I checked for any physical damage on the DIMMs on the motherboard before I installed the new RAM but there was none.

I'm pretty much convinced this is a bad motherboard. Going to RMA with ASUS when I have some free time.

 

[drdeathx]

There is nothing wrong with your board. CPUZ is showing 16G.


here is mine.

here is yours

 

[Hood]

I have seen a lot of people RMA the motherboard for this problem, lots of Asus boards won't run 4 sticks out of the box, a lot less common to have it happen after months of use. Did you try cleaning the DIMM slots?

 

[drdeathx]

I have seen a lot of people RMA the motherboard for this problem, lots of Asus boards won't run 4 sticks out of the box, a lot less common to have it happen after months of use. Did you try cleaning the DIMM slots?

That's hogwash.......CPUZ is showing 16G. If the board did not see the memory, it would show 8G. I told him earlier to check for bent pins and he ask for advise and does not get back. In most probability, he has bent pins and Asus will send the board back as is and on top of it, he went out and bought new memory. Thats funny.

 

[Lyzard]

As I said in my previous post, I already checked for physical damage, that includes bent pins, on all of the DIMM slots and there was none. I even cleaned the DIMM slots with a can of compressed air to make sure no dust was interfering with the contacts.

I tested the RAM for more than 3 passes in Memtest86 4.0a in the following configurations:
1) 4 DIMM test - 1 in each DIMM slot, 2 DIMMs per channel
2) 2 DIMM tests - 1 DIMM per channel
-- DIMM 0 Channel A and DIMM 0 Channel B
-- DIMM 1 Channel A and DIMM 1 Channel B
-- 4 tests total: 1 for each config and pair of DIMMs in the Corsair kit
3) 1 DIMM tests -1 DIMM installed in each DIMM slot at a time
-- Only 1 DIMM installed per test - a total of 4 tests performed

Memtest detected 8GB of RAM during all "2 DIMM" tests and 4GB of RAM during all "1 DIMM" tests. This rules out physical damage of the DIMM slots as Memtest would have detected only 4GB of RAM when a DIMM was installed in a damaged DIMM slot. Furthermore, the PC would not have booted if RAM was installed in a damaged DIMM slot during a "1 DIMM" test.

Yes, I agree with you that CPUz sees all 16GB when all 4 DIMMs are installed. That's where the problem is. The BIOS only sees 8GB. Windows also only sees 8GB and can only use 7.46GB even though the iGPU is disabled. Memtest86 and Ubuntu 12.04 64bit also see only 8GB.

So far, I've ruled out the following issues:
- A bad DIMM slot
- A bad DIMM
- Incompatible/outdated BIOS
- OS issue

Therefore, it has to be a failing motherboard or the memory controller on the CPU.

 

[drdeathx]

Have you called Asus? Perhaps they could shed light

 

[mgtechus]

ASUS Support

Have you called Asus? Perhaps they could shed light

ASUS support has been worthless for me. Every support group always thinks the hardware is bad.
I have been dealing with ASUS< Intel and now Corsair on why my P8Z77-V Pro/thunderbolt cannot run the kit Memory CMT32GX3M4X1866C9 *Memory Capacity : 32gb.
Runs 16mb fine!!
I have the latest bios ver 1708 settings, I have a new board (this is my 2nd one because I did have some bent pins on may last one on the cpu socket).

I have tried many different ways. XMP -1333mhz. If I let the MB pick the speed, it picks 1866 mhz but it shows 1867 mhz on the XMP profile1 9-10-9-27 and the memory is at 1.5v, just as the book states.

Intel tell me that my memory frequency supported for my I7 3770k processor is 1600MHz which equals to 800MHz, and I am running it at 1866MHz.
My Corsair memory is designed to operate at 1866MHz but the processor is the one that has the memory controller built in and it will support memory up to 1600MHz. You should load the motherboard defaults and test with the memory leaving it at the defaults. ( I DID THAT AN NO BUENO)
My memory is dual pump, meaning that in your motherboard if you read 800MHz it means that it is working at 1600MHz, if you get it to 933 it means that it is running at 1866MHz.
The Serial Presence Detect (SPD) settings on the memory are 1333MHz that is how you should test them. If it works then you can change it to 1600MHz.

Corsair tells me to exchange the memory (RMA) I told them the memory isn't bad because I have swapped them memory around and all Sims work but only in A1 & A2 slot.
However the ASUS MB book stats for 16mb use dimm slots A2 & B2. Mine will not work that way. It only works in A1&A2.
32GB of memory will work with your system, but if you still have problems, you may want to increase the voltage slightly to 1.65 to give the memory controller increase compatibility across all DIMM slots being filled.

This isn't rocket science so has anyone been successful with 32mb?

I am about to clear my CMOS and try again.

 

[Aquinus]

Have you tried reseating the CPU itself, inspecting the socket and make sure to not put the cooler on too tight? I've heard some people say that if they tightened their cooler too much PCI-E slots will stop working or DRAM will have issues. So if you haven't resat your CPU, it would give it a try.

 

[mgtechus]

Have you tried reseating the CPU itself, inspecting the socket and make sure to not put the cooler on too tight? I've heard some people say that if they tightened their cooler too much PCI-E slots will stop working or DRAM will have issues. So if you haven't resat your CPU, it would give it a try.

That will have to be my last option because I have a large Zalmon CPU fan and I may have to remove the MB to add it back on.

 

[Sinzia]

I'd lean more to a re-seat of the cpu before I'd rma the board, I've heard of missing half the ram and this almost always fixed it.

 

[mgtechus]

More problems

I'd lean more to a re-seat of the cpu before I'd rma the board, I've heard of missing half the ram and this almost always fixed it.

Ok after I cleared the CMOS now the board doesn't even like 16mb but will boot up with 8mb.

Now I am removing the fan and checking the cpu. No bent pins so putting it all back together.
I seriously think my CPU is causing my issues.

Let you know the outcome later.

 

[drdeathx]

Can you take a photo of the pins to verify?

 

[mgtechus]

Can you take a photo of the pins to verify?

Sorry its already back together. I did take a magnifying glass and look for bent pins. I have to remove the motherboard because its a bitch trying to get that Zalmon CPU fan back on. I didn't really tighten the fan down that much this time and all looked normal.
I just now booted up in Windows. After clearing that CMOS my machine had a hard time starting. So I just left it alone after several tries yesterday and this morning it booted right into windows again on 16mb. I have to boot in CMOS here in a few and see whats going on.

 

[Aquinus]

So I just left it alone after several tries yesterday and this morning it booted right into windows again on 16mb.

I didn't know Windows could boot with 16Mb. Does it still not detect the other 8GB?

However the ASUS MB book stats for 16mb use dimm slots A2 & B2. Mine will not work that way. It only works in A1&A2.

This sounds like the IMC. It wouldn't be in dual channel if you put them both in A1 and A2 though. Which means only one channel is working? Do neither B1 or B2 work?

 

[mgtechus]

I didn't know Windows could boot with 16Mb. Does it still not detect the other 8GB?


This sounds like the IMC. It wouldn't be in dual channel if you put them both in A1 and A2 though. Which means only one channel is working? Do neither B1 or B2 work?

Yes it shows 16mb but the channels # shows Single.
I have not been successful in B1 or B2

 

[mgtechus]

I didn't know Windows could boot with 16Mb. Does it still not detect the other 8GB?


This sounds like the IMC. It wouldn't be in dual channel if you put them both in A1 and A2 though. Which means only one channel is working? Do neither B1 or B2 work?

So I never heard of a IMC going bad. This is my 2nd board and about to replace the memory.
Is it possible that the CPU could be causing this problem? That I haven't replaced. This is all new hardware so I am a bit frustrated.


Has anyone ran their voltage higher. Corsair said bump mine higher.

 

[Lyzard]

I'm gonna reseat the CPU sometime next week when I have time off work. Doubt it'll fix it but it's worth a shot. I'll try anything at this point to avoid dealing with ASUS support.

I wish I can get my hands on a 16GB (2 x 8GB) kit to see if my MB can see more than 8GB or RAM. I returned the Corsair RAM I bought since it didn't fix the issue. That was the only reason I bought it in the first place.