8gb installed, showing as 4gb usable!

[RaptorZX3]

Hi!

i have 2 x 4gb RAM kits of F3-12800CL7D-4GBRM, using the XMP profile on them

Now before i had 4gb available, now with 8gb, i still have 4gb only available in Windows 7 Home Premium 64-bit.

before telling me to swap RAM sticks around on my board, i did tested my games, updating Windows with patches and everything, and all RAM sticks seem to work fine.

I heard this is normal as Windows reserves memory for other things if it's not used. This is caused by the Memory Remap feature in the BIOS i think.

Now, i wonder...if some unused reserved RAM is finally needed, will Windows release a bit of this RAM to make it available for the software that will need it?

Because 4gb of reserved RAM is a lot of memory i can't use for myself?

And with that reserved memory, does that mean Windows and its drivers now runs faster since Windows took this memory for itself as some kind of "dedicated" memory?

[photonboy]

tips

Things to check:
1) You have a 64-bit Operating 7 (such as Windows 7 x64 Premium)

2) Your motherboard supports 8GB of RAM (see manual. It's almost certain it does)

3) Run Memtest from disk or from Windows 7 (or Vista?). Does Memtest show 8GB (multiply 8x1024x1024 for the amount in KB or KiloBytes)

4) Is 8GB displayed during Bootup or in your BIOS?

5) Still stumped? Try only 4GB at a time; make sure you choose the correct slots such as 1 and 3 or 2 and 4 (see manual). Run Memtest and repeat for other 4GB to verify the RAM is okay.

6) Do you have Tri-Channel (such as x58). I doubt it but I had to ask. If so, you probably have six slots and would use a 3x2GB setup.

*Note that if Memtest or BIOS show 8GB it's probably working, you may be reading it incorrectly. In Task Manager -> Processes, the "Total Physical Memory" should be about 8192MB

[photonboy]

follow up

Ignore my 64-bit comment.

The most likely scenario is that you're reading the wrong information and that you do have all 8GB available.

[photonboy]

8gb vs 4gb

Extensive testing has shown no noticeable difference in performance between 4GB and 8GB. The exception is for professionals editing massive picture or video files.

There's ZERO performance difference in games.

The most optimal setup for performance/price is something like this:

1) 4GB DDR3
2) 60GB SSD or (for Windows 7 x64 and programs; good SSD can get over 250MB/sec. I have 2x60GB in RAID0 using Intel ICH0 controller for 500MB/sec)
3) WD 1TB hard drive (for games and backup files. Consider partitioning)

*The above setup is very snappy for basic Windows tasks. A $160 60GB SSD makes a big difference, but games must be told to install to the hard drive due to space (I just change the "c" to "e" (my 300GB Velociraptor is on E-drive) during game setup.

[RaptorZX3]

i did removed the new 2 x 2gb.

Yes i have Windows 7 64bits Home Premium, my board supports 4gb RAM sticks and up to 16gb (so 4 slots).

Now here's the whole story:

-Previously, there was 4gb "reserved". Then someone told me to swap both new RAM sticks, i did it, and it seemed to work, Windows detecting the full 8gb without any RAM reserved. But then later, i was getting BSODs, crashes, instability, Windows unable to boot properly, video card not able to load its drivers, sound card not able to play sound and later wouldn't play thru my speakers (only SPDIF was available).

-I did tried to restore at different points, it never helped, always telling me it couldn't restore to that point and to try another one, going in safe mode, trying to restore...nope.

-So what i did is reinstall Windows, the installation process took a long while to move everything into the "Windows.old" folder before starting the process...

-Now it seem to be stable, with the previous 2 x 2gb of RAM, except i'm feeling that Windows is slower at booting, my hard disk LED flashed less (it normally tend to brighten and dim while in continuous access, well not anymore, i wonder why...)...

-and, this happened a few times, on the new Windows installation, it seem like Aero turn itself off sometimes after a while of inactivity...anything i can do to ALWAYS have Aero on and never turning itself off?

[photonboy]

ram and file system corruption

Be aware that if your RAM isn't quite working your file system can easily be corrupted.

NEVER startup Windows until you have run Memtest and show no errors (or at least pass the basic test).

Recommendation:
1) Backup Windows if working (Acronis True Image or Windows Image)

2) Shutdown and UNHOOK all non-Windows drives (such as a backup and storage drive)

3) Boot to Memtest (make a USB stick or CD-Drive. May need to change the boot order. I use USB->CD->Hard Drive so it looks for bootable media on the USB stick, then a CD or DVD first.

4) Continue to run Memtest and adjust BIOS timing for Memory until Memtest shows no errors if possible

5) If no errors, hook up other drives and boot (sometimes adding drives changes the hard drive boot order. No bootable disc can cause a black screen with cursor flashing)

6) If you have errors, you need to RMA (note, only 1 stick might be bad or two out of four. It's a pain to return two sticks if that's all you have, but if you purchased as a pair they're returned that way.)

[photonboy]

re corruption

To be clear:

a) I lost several folders of videos and other files due to the corruption.

b) If your Windows drive is corrupted it may be hard to tell when your RAM is actually working. You can: reinstall Windows, or restore a known working backup.

*Unfortunately, if your Windows installation is corrupted at all it's impossible to know the extent of it. You'll need to reinstall.

[RaptorZX3]

i had to reinstall in fact...and found that Windows ran quite slower than before, so i used MyDefrag, picking the "System Disk, Optimize Monthly" choice, took a few hours since i have around 640gb free still on this 1Tb WD10EALS drive. There IS a big booting speed difference now!

I didn't run the Memtest in question, i took both RAM sticks out and put them back in their original G.Skill plastic package. When the time will come, i will put them in again and do what you said. I have Memtest86+ 4.10 on a bootable CD/DVD.

So i have to disconnect all storage devices other than the optical drive? (there's only 1 hard disk in my computer anyway.

For now i don't really need that extra memory, but eventually i will, and G.Skill gives a lifetime warranty on them. I'll put a reminder paper and the Memtest disc with the RAM sticks, so i won't forget to test them before.

But is there a G.Skill technician/expert who can tell me which IMC voltage i would need for 4 sticks of this memory on my board? it's an Asus P7P55D-E LX. I'm using the built-in XMP Profile in the memory

[photonboy]

all the same memory

You can have problems if you don't use all the same memory.

On my old computer I had 4GB (2x1GB Antec and 2x1GB OCZ) for 4x1GB. With either set of only 2GB it was stable but I had problems like you did with all four sticks installed.

I played around and got the timings correct but any memory manufacturer will recommend that you use only EXACTLY the same type of RAM, not just two nearly identical sticks.

AERO turning OFF and ON? Your desktop should never swith to non-Aero. it will switch when starting games or other programs but then you don't see the desktop and it switches back when you close the game.

To confirm from scratch:
1) Run a FULL MEMTEST on RAM (boot from CD or USB or floppy)
2) Install Windows 7 x64 (i.e. Premium) using FULL NTFS formatting.
3) Activate
4) Immediately do a BACKUP using a program like Acronis True Image that can RESTORE the entire IMAGE if needed (BACKUP again later after installing all programs)

*If you mess around with 8GB, remember to:
1) turn off PC and disconnect all hard drives (avoid corruption)
2) Install the RAM
3) run MEMTEST
4) problems? experiment with frequency and timings
5) run MEMTEST again

repeat until MEMTEST reports no errors after at least three full passes (several hours)

[wevsspot]

Running Memtest on each of the memory sticks by themselves at BIOS defaults is a great recommendation and I'd take that one step further. Clear your CMOS and reload BIOS defaults before you begin testing.

Do not use the XMP profile, but instead manually enter in the mfg. specified DRAM voltage and the four primary memory timings.

For your memory kits that would be;

1.65v DRAM Voltage
7-8-7-24 2N

Leave all other advanced memory configuration options in the BIOS set to Auto

[RaptorZX3]

the RAM voltage is 1.6V, and i have the exact same kind of RAM for all 4 of them, i bought a 2 x 2gb kit a month ago to replace the awful OCZ kit i had, and then i decided to buy more RAM and bought the same G.Skill kit to match the previous kit i already installed.

I asked a friend who's a tech in a Staples (he's very good actually), and he said it's most probably bad/corrupted RAM.

i have no problem running with the XMP profile, really, it even boost the CPU speed a little, which is a plus, not by much, it's like...2.73Ghz instead of 2.67Ghz, and the CPU is running cool still, around 35-37 Celcius (and i have a really good heatsink also, a Prolimatech Megahalems rev.B) with a Nexus 120mm fan on it

[photonboy]

corrupted ram

Memtest catches 99% of bad RAM.

There may be slight voltage fluctuations or thermal considerations under normal use that Memtest can't catch.

http://www.memtest.org/ (get v4.10 ; the floppy is the easiest if you have a drive. next I recommend the CD. the USB stick isn't the best because you'd have to either dedicate a USB stick to that or reflash it everytime you do this.)

[RaptorZX3]

even there i have the feeling the RAM might be corrupted.

I might contact G.Skill support about this, hopefully i won't pay the return shipping to them...Do they give out a prepaid printable shipping label for RMA?)

[wevsspot]

the RAM voltage is 1.6V

Your DRAM voltage is set too low. GSkill specifies 1.65v for this kit to run at it's rated speed and timings. And that is for a single 4Gb kit. Running 8Gb might even require a small DRAM voltage bump above 1.65

[RaptorZX3]

look at this link:
http://www.gskill.com/products.php?index=243

This is the kit i have actually in my computer, and it says 1.6V. I removed the identical kit that seem to have corrupted memory on it. I may contact G.Skill support soon.