64-bit PC only has 3.20 gigs of ram.

[romancandle]

I built this rig about a yea ago and ever since have had performance issues. Sometimes it will run everything just fine, and other times it will almost lockup just opening chrome, even if it has just booted up (and finished loading everything).

I thought it was my APU at fault, but just recently I checked my system properties again and even though I have 3 2GB DDr3 DIMM's only 3.20GB is "usable" Don't know how I missed that before.

I've run memtest overnight and it showed no issues.

My Specs:
System properties: http://puu.sh/fszsP/73c7b51adb.png
OS: Windows 7 Ultimate 64-bit
APU: A6-5400K 3.6Ghz single core
Mobo: F2A55-M/CSM
RAM: https://www.amazon.com/gp/product/B001R4BT1M/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B001NA25VS/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

 

[Ck1_13]

That's an interesting one, I would expect you to be running 32bit OS. I did some searching and came up with this:

http://www.tomshardware.com/answers/id-1636054/9gb-useable-8gb-windows-64bit.html

It's a bit of a read, but It's a starting point.

 

[junkeymonkey]

''with mb you can put one stick of ram in at a time. the issue with 3 sticks or one sticks is the memory controller will run in single channel mode not duel channel mode so you take a slight hit on performance. just make sure the ram all the same size and speed. in real world your better off using match dimm kits. and not adding a new kit and a old dimm together. ''


so your board is not made for tri channel set up and it maybe just having issues with 3 sticks in a duel channel board its best to use 1- 2-4 sticks

so that's how I would look at it

 

[romancandle]

Ok I've fixed it, I read another thread which mentioned removing sticks and booting with them 1 by one, but I noticed that I put one of the kit sticks and the other sticks on the same channel.

I've switched them and everything is soooo much faster now. And my usable ram is up to 5.20GB (instead of 6 because of hardware requirements). Thanks for the quick replies! Hope this helps anyone experiencing similar problems!