Laptop has 8GB installed 3.74 usable

[uofarsx]

Hi, I have an Acer 5551 laptop and I just installed 8gb of ram and it says only 3.74 usable. The laptop has Windows 7 64-bit. When I check the bios it says 8gb installed, and memory remapping isn't a choice in the Bios. I tried lots of interesting things and read lots of forums. Here is what I have tried that hasn't worked:
1. I turned max memory off.
2. I set max memory to 8gb.
3. I updated the BIOS and video card drivers to current versions.
4. Switched the RAM in different DIMM slots (only 2)

So after I tried all of those it and nothing worked, I found something interesting. If I take out one DIMM the laptop says 4gb installed and 3.74 usable. Does this mean that I can only use one slot on my laptop? Both Windows and the Bios recognize that it has 8gb installed though. Thanks for any help, its kind of frustrating and I may just return one of them, and only use 4gb. Thanks again for any help.

 

[jaquith]

Welcome to Tom's Forum!

IF the RAM has different Frequency, CAS Timings, or in particular Voltage then your BIOS might be simply shutting (1) down to prevent errors/damage. Also, with (1) stick have you tested BOTH DIMM slots e.g. | 4GB | blank | and | blank | 4GB |. Therefore, you might have a mix-match {incompatible} problem or bad DIMM Slot. Use CPU-z to identify your RAM -> http://www.cpuid.com/softwares/cpu-z.html

Q - please link to you exact RAM.

BIOS IMO use 2.13 -> http://us.acer.com/ac/en/US/content/drivers

Specs:
Memory Type: DDR3 PC3-8500, DDR3 PC3-10600, DDR3 (non-ECC)
Maximum Memory: 8GB
Slots: 2
Each memory slot can hold DDR3 PC3-8500, DDR3 PC3-10600 with a maximum of 4GB per slot.*

 

[uofarsx]

This is the RAM I got:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231266

I bought two of them less than a week ago.

I think I might have a bad DIMM slot because when I tried 1 blank and 4gb the computer wouldn't even post. I thought that I had to have it in the bottom slot though for the computer to turn on, but I guess i have a bad slot. Anyway to fix this?

 

[jaquith]

You can 'try' to 1. Blow-out dust/debris with compressed air, 2. Isopropyl alcohol - dampen the RAM contacts, insert moist, pull-out wipe-off and repeat, remove for 5 minutes to dry. Install both sets and keep your fingers crossed. 😉