I;ve just installed windows on my newly built PC, and I realized that only half of my installed RAM is available for use IN windows (my BIOS does detect the whole 8GB of it). What might be causing this problem?? I am using windows 7 ultimate 64 bit.
I had a very similar problem albeit with 16GB (4x 4GB sticks). I just tested them one at time using memtest86 it took awhile but I eventually discovered I had a bad stick I had to RMA. No mater the brand or much quality control goes into a product eventually something happens just hope you get good customer support like I did. AMD paid 176$ to fedex overnite my replacement stick to me in Germany from US.
http://www.memtest86.com/
Maybe you don't have them inserted to your motherboard correctly. Remember, if you put one stick of ram in slot 1 and you have 4 slots, put the other one in slot 3. This is of course if you have 2 sticks.
you score 0 for comprehension. Good job.
can also try msconfig - boot - advanced options - select max memory
Before you go through the whole memtest longness
The problem persists... Windows says I have full 8 GB installed, but next to it says that I can only use 4... what may be causing this? Should I run memtest?
Uhh maybe you are running a 32bit version of windows.
As I stated in the post, I am using Win7 Ultimate 64-bit. I am 100% positive about this.
is the ram all the same speed? what speed does your bios have it clocked at?
Yes, same speed, bought it in the same kit. BIOS marks it as 1600MHz (the speed I bought it for).
Try running just one stick at a time to see if you have a bad stick.
Both sticks are working (already checked them) what might be the issue is a bad Mother Board... the 3rd and 4th RAM Slots do detect the RAM but do not POST when I turn the computer on.