4GB Memory Unusable

[veldthui]

I finally got my new I7 980X CPU today so went to fire up my newly built PC but the POST screen only shows 4GB of memory. Re-seated the chips and still only 4GB. Memtest86+ V4 shows all 4 sticks of 2GB Corsair ram as present but only says 4GB as well.

Installed Windows 7 and it says 8GB installed. 4GB usable. This is the 64bit version so I am expecting to get the whole 8GB.

Anyone know who or what is holding the other 4GB to ransom and what do I have to pay to get it released?

 

[Brian6121990]

I finally got my new I7 980X CPU today so went to fire up my newly built PC but the POST screen only shows 4GB of memory. Re-seated the chips and still only 4GB. Memtest86+ V4 shows all 4 sticks of 2GB Corsair ram as present but only says 4GB as well.

Installed Windows 7 and it says 8GB installed. 4GB usable. This is the 64bit version so I am expecting to get the whole 8GB.

Anyone know who or what is holding the other 4GB to ransom and what do I have to pay to get it released?

IS the bios set to read 8gb ram?

 

[smarteyeball]

When the machine POSTS, does it show 4GB or 8GB? How much does it show in the BIOS?

Is it only happening since you replaced the CPU, or is it an entirely new machine totally built from scratch (including the RAM)?

There are several causes for this:

► RAM Timings to aggressive/tight (loosen the timings)
► Insufficient DRAM volts
► Poorly Seated CPU - improper pad/pin contact (re-seat it)
► Cooler too tight/ loose (cooler tension affects the pin/pad contact)
► Bad RAM modules
► Bad dimm slots

 

[veldthui]

It is brand spanking new all round. POST shows 4GB. Have everything in the BIOS set to auto so timings should be pretty loose as I wanted to get it working before starting to tweak. The memory chips speeds are rated much higher than what they are actually running at (needed room to move).

Will try the CPU cooler. It was a dog to get on. Artic Cooler Pro and has two screws to tighten but you cant see them to put them in.

 

[zigzag3143]

It is brand spanking new all round. POST shows 4GB. Have everything in the BIOS set to auto so timings should be pretty loose as I wanted to get it working before starting to tweak. The memory chips speeds are rated much higher than what they are actually running at (needed room to move).

Will try the CPU cooler. It was a dog to get on. Artic Cooler Pro and has two screws to tighten but you cant see them to put them in.

Check what max memory is set to in msconfig. (type msconfig in search). It should be unchecked.

 

[smarteyeball]

POST shows 4GB. Have everything in the BIOS set to auto so timings should be pretty loose

Will try the CPU cooler. It was a dog to get on. Artic Cooler Pro and has two screws to tighten but you cant see them to put them in.

Yep, auto should be loose enough.

Although to double check you could set it to 9-9-9-24 or so @ 1066mhz with a TN of 2 to completely rule out timings

The fact that POST/BIOS shows only 4GB points to it being hardware. So there will nothing that can be done within from Windows itself.

I had a similar issue with this current build initially - I kept losing 2GB while POSTing and it turned out to be the CPU cooler tension. Once adjusted properly, it's been solid.

But I also managed to replicate the memory loss at post when tweaking my RAM. So yeah, there are several possible causes.

 

[chev65]

Besides trying Smarteyeballs good advice I would try the following procedure.

I would try shutting down the machine, unplug power from PSU and drain power by pushing start button. Remove half the Ram from every other slot. Restart the machine check to make sure all 4GB are picked up by Windows. Shut down again and repeat procedure of draining power, install one stick at a time repeating the same procedure each time and see if Windows picks them up each time you restart.

 

[veldthui]

I tried the cooler. When I loosened it off it only POSTed 2GB. When I tighten it back up regardless of how much it still only POST's 4GB. What is strange is that MemTest86 and Windows both show 8GB there. Windows 8GB installed, 4Usable. MemTest86 shows all 4 stcks of 2GB but again only tests 4GB of it.

Cant see any options in the BIOS that would disable the mem. The timings are 7-7-7-24 @ 2020mhz. Well within the specs of them.

 

[bobkn]

I tried the cooler. When I loosened it off it only POSTed 2GB. When I tighten it back up regardless of how much it still only POST's 4GB. What is strange is that MemTest86 and Windows both show 8GB there. Windows 8GB installed, 4Usable. MemTest86 shows all 4 stcks of 2GB but again only tests 4GB of it.

Cant see any options in the BIOS that would disable the mem. The timings are 7-7-7-24 @ 2020mhz. Well within the specs of them.

Here's a semi-random suggestion:

Your system must support triple channel memory. What happens when you use only 3 DIMMs, in a triple channel configuration?

 

[veldthui]

The system is a DDR3 system with 6 DIMM slots. It says to stick memory into slots 2,1,3,5 for 4 modules. I stuck one moduke in 1 and it would not POST. 2 modules in 1 & 3 and it posted with 2GB. 3 modules in 1,3,5 and it posted with 4GB. I then tried slots 4 and 5 with more modules and got the 8GB. However it will work with anything in slots 1 & 2. It is detected but it wont POST the size and it cant be used.

I may have a faulty motherboard. I have had one BSOD as well with the 8GB but I was playing around with the timings and it may not like the memory in the other slots. The manual says 1 first but it is out of action.

 

[fseal]

2020 MHz memory clock?!?!?!

And with the i7980 you really should be running tripple channel, either 6 gig in slots 13 and 5 or 12 in all slots.

 

[smarteyeball]

I tried the cooler. When I loosened it off it only POSTed 2GB. When I tighten it back up regardless of how much it still only POST's 4GB.

Unfortunately cooler tension related issues are a fine line. When the mobo is mounted vertically, gravity and the weight of the plays a part.

Depending on how the screws are tightened (both the bracket and mount) can effect the CPU contact as the 'top' of the cooler (end closest to the top of the case) bows down under the weight to 'lift' the CPU off the pins just enough to affect it negatively.



Is this your Cooler? :

Newegg.com - ARCTIC COOLING Freezer 7 Pro Rev.2 92mm Fluid Dynamic CPU Cooler

It appears to have a plastic bracket - The bracket and cpu mount could be flexing.

I assume you have it mounted horizontally? (exhausting to the rear)

Theoretically if you keep the top two bracket screws a tad tighter than the bottom two, it may help compensate with any flexing.

What is strange is that MemTest86 and Windows both show 8GB there. Windows 8GB installed, 4Usable. MemTest86 shows all 4 stcks of 2GB but again only tests 4GB of it.

For me, Windows didn't show all the RAM (yet CPU-Z did) but memtest did show all the RAM but only tested 4GB

Cant see any options in the BIOS that would disable the mem. The timings are 7-7-7-24 @ 2020mhz. Well within the specs of them.

What board are you using and what is the model number of your RAM?

7-7-7-24 @ 2020mhz is actually pretty tight. Are they 2 2x2GB kits?

They may be rated for 7-7-7-24 @ 2020mhz in a 4GB config, but not for 8GB.

In fact at that clock speed, they are damn aggressive timings.

 

[veldthui]

No that is not the one. Similar though. This is a later model and has the fan between two slabs of fins. You pull the fan out to do up the two screws. It has Freezer Extreme plastered over the top.
The base looks the same but has 4 pins that push through the MB. The cooler is then screwed by two screws onto the base. The screws are verticle when on its side. The plate that the screws go through is sprung. I would not have thought you could really overtighten this unless you screwed them right down.
I have had the tower on its side all day it makes no difference. The first two slots simply wont register properly.
The MB is a Gigabyte X58A-UD7 and the BIOS has plenty of settings. One is to allow the BIOS to set the speeds based on the XMP settings in the chip. Using this sets the top speed i quoted. When this is off it is running at 1333mzh and still wont see the 2 slots.
The ram is Corsair XMS3 DOMINATOR GT CMG4GX3M2A2000C8, 2x2GB, DDR3-2000, PC3-16000, CL8, DIMM. Got two packs for 8GB total.

 

[smarteyeball]

As an elimination test, with only one module installed into DDR3_3, (4th slot from the CPU)

In the BIOS, manually enter the settings:

MB Intelligent Tweaker(M.I.T)

XMP [disabled]

Memory Frequency : leave @ 1333 for now, or even 1066mhz
DRAM Timing Selectable : [Manual]
Profile DDR Voltage 1.64/1.66 (A lot of boards don't have 1.65v as an option)
Profile QPI voltage 1.2v up to 1.25v to be sure. (QPI is similarish to the old NB setting - the more dimms filled, the more volts needed. Especially @ higher speeds and timings)

CAS latency : 8
tRCD : 8
tRP : 8
tRAS : 24

Leave the rest on AUTO for now.

Save settings and shut down. (this will ensure you definitely have enough volts and loose enough settings)

***

POST the machine with each individual module in slot DDR3_3 for a quick check that all modules will at least start the machine. (saves on memtest runs for now)

(start with DDR3_3 since it's a known 'good' dimm slot. With a single module, that board will only post from DDR3_1 & DDR3_3 )


Now remove a module from DDR3_3 and place it into to DDR3_1 (2nd slot from CPU)

► If the machine fails to POST - the dimm slot is probably bad = bad mobo.

► If the machine does POST - add the 2nd module into DDR3_3 and then add the third module into DDR3_5 slot.


Once added, does the machine now show 6GB at POST/BIOS?

If yes add the last module into DDR3_2.

If not... then there is more testing to be done.

 

[veldthui]

It wont POST with any of the modules in DDR3_1 but will with DDR3_3.

I now have the 8GB available but in 3,4,5, and 6. Get nothing out of 1 or 2. I even put the stock CPU cooler on which has 4 screws so the tension was better spread but no difference.

I have RA'ed the board to get a replacement as two slots are obviously not working for whatever reason. I have done 6 PC's now and this is the first time I have ever had trouble that was not easy to fix.

Will let you know how I get on. The machine is nice as is and extremely fast. The CPU surprised me because some of the reviews had notes of the CPU running hot having 6 cores. With the Freezer Extreme I had the temps at 18-21 and with the stock cooler 23-29. Has not really been under load yet for some serious work but FSX did not seem to bother it at all.

 

[smarteyeball]

Dead dimm = dud mobo. Good call on the RA.

Running on 3,4,5,6 would have knocked you back to dual channel instead of tri.

No point in settling for a dud. Fingers crossed the replacement is fine.

 

[EpicThorn]

Question: How can it even run in Triple Channel mode when there is only 4 sticks of RAM?

 

[smarteyeball]

Some X58 boards can retain tri channel with four modules. (UD7 is one of them)

The fourth module has to be in a particular dimm, otherwise it reverts to dual channel.

3x2GB = 3 sticks minimum for tri channel

 

[veldthui]

Okay have found the problem. As I was taking the parts out I was checking each bit very carefully seeing as it all had to come out. After cleaning the paste off the CPU I lifted it out of the socket and there looked to be something strange with the array of pins. Using a torch it looks like there are two areas of pins that are pushed down. One group in the middle and one group on the outside. Did not have a maginifying glass so could not tell for certain. Just goes to show you even with the missing pins the CPU was working quite well. Still stable but just not the memory configuration.

Just not my month.
A $5 case fan took out my GTX8800 and X65 motherboard in my other PC. Could not get the right MB for it and had to buy a refurbished one.
Doctors think I have kidney stones and last weekend my Honda quad decided it didnt like the way I rode it and rolled onto me landing its 300Kg weight on my left leg.
Now my new MB is faulty. Hurry up August.......

 

[Kirsch]

Just not my month.
A $5 case fan took out my GTX8800 and X65 motherboard in my other PC. Could not get the right MB for it and had to buy a refurbished one.
Doctors think I have kidney stones and last weekend my Honda quad decided it didnt like the way I rode it and rolled onto me landing its 300Kg weight on my left leg.
Now my new MB is faulty. Hurry up August.......

Sorry to hear