• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

What determines the maximum amount of RAM a computer can upgrade to?

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

Fishsticks

New Member
Joined
Nov 19, 2009
My laptop, an HP Pavilion dv6871us, has 3 GB RAM (has a 1 GB stick and a 2 GB stick) and I want to upgrade to a higher amount of ram. On the manufacturer's website, it says that the dv6871us can have up to 4 GB with 2 sticks of 2 GB.

Is there some reason my laptop may not be able to use 2 4GB sticks of RAM for 8 GB Max in a 64 bit OS (such as hardware or bios limits) or is HP assuming that I will only use 2GB sticks in upgrading?
 

MARCI

Member
Joined
Jun 19, 2008
Location
Folding for T32 in Lawrenceville, Ga
The Bios, and memory controller on the Mobo, determine the maximum capacity Memory modules that are compatible, and the number of physical Dimm Slots determines the maximum number of modules that can be installed.
 

Rider200

Member
Joined
Jun 3, 2008
Location
Arizona
There is another factor that will limit the maximum amout of ram for a given BIOS/Motherboard and that is if the RAM manufactures see a need to make a larger module.

My T-30 was limited to 1 Gig of ram (two 512Meg modules) until last year, now there are 1 and 2 Gig Modules for the IBM T-30 and upwards.

Tell you what, go to Kingston and plug your computer make and model number in their wizard and see if there is a module that you can use. The price of memory is low enough that you can afford to experiment.

Part of the problem with newer ram is the power factor, does your motherboard support different voltages? If it is regulated at say 1.38v then a 1.5v module will not work or if it is regulated at 1.5v you don't want to waste a 1.38v module by putting it in the slot because it will smoke. See what I mean? (Saw that on my last job, a guy took the memory out of a T-60 and put it in a T-40, the smell was around for a longgggg time).

MHO...
 

TheGreySpectre

Member
Joined
Sep 6, 2003
There are a couple things that limit you. First off there is the Operating system a 32bit operating system can't use more then 4 gigs of ram, and even then they only really use like 3.2 of that due to addressable memory locations. 64bit operating systems have a support of a maximum of 16 exabytes of ram (16 million terabytes).

There is also the factor of slots on the motherboard. 4gig sticks are the biggest avialble right now so you are physicaly limited to 4x the number of ram slots on your motherboard.

I see no reason why you could not put 4 gig sticks in your system. But I have not worked on a company built computer in quite a while.
 

Daddyjaxx

Member
Joined
Jan 5, 2005
Location
Ormond Beach, FL.
Just because you have the slots available, does not mean that the system can address it. All that Marci posted will determine if the computer can see it.

Not memory related, but for the same reasons, until the last BIOS update, my motherboard could not address 2 TB hard drives.
 
OP
F

Fishsticks

New Member
Joined
Nov 19, 2009
I figured bios might be a limitation but I wasn't sure. I didn't think the motherboard itself might be the limiting factor though. I do know that if I try going beyond 4 GB RAM I'll at least need to have a 64 bit OS to work with it and that my motherboard only has 2 memory slots total. My best hope is to ask HP whether the bios they've provided or my motherboard could limit me from going beyond 4GB if I attempt to use memory sticks larger than 2GB sticks in my 2 memory slots. Just to stay on the safe side, I may upgrade my 1GB stick to match the 2GB stick I have for 4GB total and use Vista 32bit + PAE.
Regardless, thanks for your responses. I'll definitely give the decision more time now and see if I can find out more about my bios, motherboard, and memory controller from HP and/or Intel.