BIOS not using full 4 gigs of RAM despite 64 bit processor

Dev Hardware Forums Sponsor:

Trader Rating: 0 · #1

January 25th, 2009, 03:28 PM

akorpija

n00b DevH'er

Join Date: Jan 2009

Posts: 5

Time spent in forums: 44 m 19 sec
Reputation Power: 0

BIOS not using full 4 gigs of RAM despite 64 bit processor

So the problem I'm being faced with is that my BIOS understands that there are 4 gigs of RAM, but tells me that only 3.3 gigs are available. I've attached a screenshot so you can see what I'm talking about...

What I don't get is why it's doing this...I haven't the rest of the RAM to anything else since there are no BIOS settings to do that (not even for my shared video RAM) so I'm wondering where the other 700 megs of RAM are going, since they're unavailable

And yes I do have a 64 bit processor, and I'm also running both Ubuntu 64 bit and Windows 7 64 bit so that's not the issue...not that the OS's matter since the BIOS is what's telling me that only 3.3 gigs are available.

Any help greatly appreciated!

*** I can't attach a picture since links aren't allowed and i can't figure out how to upload a pic to this....

Trader Rating: 1 · #2

January 25th, 2009, 04:06 PM

drumz0rz

usergroup or postcount

Join Date: Jun 2004

Location: NY/PA

Posts: 5,963

Folding Points: 837587 Folding Title: Super Ultimate Folder - Level 2

Time spent in forums: 5 Months 3 Weeks 6 Days 1 h 3 m 43 sec
Reputation Power: 13055

Send a message via Google Talk to drumz0rz

Hmm.. what motherboard is it? Have you checked to make sure the BIOS is up to date?

__________________

Trader Rating: 5 · #3

January 25th, 2009, 04:31 PM

Stang

Vid card geek

Dev Hardware Frequenter (2500 - 2999 posts)

Join Date: Sep 2004

Location: Austin Texas

Posts: 2,632

Folding Points: 4357897 Folding Title: Super Ultimate Folder - Level 9

Time spent in forums: 1 Month 5 Days 12 h 37 m 22 sec
Reputation Power: 7922

the chipset may be an issue, some chipsets will not support 4gb of memory, regardless of the OS used. The Intel Lakeport chipsets (945 series) for instance did not support memory remapping, so most versions of the chipset would not support 4gb of ram.

Please post your system specs, knowing the motherboard as drumz0rz noted would at least allow us to determine the chipset and if that is not the limiting factor, or if there is a bios update that could resolve any potential issue.

__________________

Trader Rating: 0 · #4

January 25th, 2009, 04:43 PM

akorpija

n00b DevH'er

Join Date: Jan 2009

Posts: 5

Time spent in forums: 44 m 19 sec
Reputation Power: 0

System Specs

hey, forgot to mention my specs!

Intel Core 2 Duo T7200 @ 2.00ghz (64 bit)
4 GB RAM
Intel GMA 950

As for the motherboard I can't figure out exactly what it is, but i'm using a Dell Inspiron 640m

The BIOS is up-to-date, and there are no options for how I use the memory

Trader Rating: 0 · #5

January 25th, 2009, 05:14 PM

hoskind1

Contributing User

Join Date: Dec 2008

Posts: 84

Time spent in forums: 16 h 40 m 39 sec
Reputation Power: 86

Hi, just so i dont sound like an idiot, this is a laptop yes?

If it is, according to several site's the max ram it can take is 2gb...
yet it shows up as 3.3gb ... weird.

Trader Rating: 0 · #6

January 25th, 2009, 05:22 PM

akorpija

n00b DevH'er

Join Date: Jan 2009

Posts: 5

Time spent in forums: 44 m 19 sec
Reputation Power: 0

Yup it's a laptop

And I didn't realize that but wow! I think you're really onto something...I wonder what would limit it to 2 gigs in the first place...weird that it reads as 3.3 since that's what a 32 bit system could go up to (or I've read really it's 3.2 gigs)

Strange, but I guess 3.3 is the most it'll go up to then, and I'm lucky enough for that if it's supposed to be limited to 2 gigs...

Thanks a lot!

Trader Rating: 0 · #7

January 25th, 2009, 05:23 PM

akorpija

n00b DevH'er

Join Date: Jan 2009

Posts: 5

Time spent in forums: 44 m 19 sec
Reputation Power: 0

Although it's still interesting that the BIOS knows that there are 4 gigs installed but says only 3.3 gigs can be used...

Trader Rating: 1 · #8

January 25th, 2009, 05:30 PM

drumz0rz

usergroup or postcount

Join Date: Jun 2004

Location: NY/PA

Posts: 5,963

Time spent in forums: 5 Months 3 Weeks 6 Days 1 h 3 m 43 sec
Reputation Power: 13055

Most of Dell's laptops can only support 2GB. It's most likely due to the chipset issue as Stang mentioned. I'm surprised you see 3.3GB.

Trader Rating: 0 · #9

January 25th, 2009, 09:36 PM

MisterEd

Contributing User

Dev Hardware Beginner (1000 - 1499 posts)

Join Date: Apr 2004

Location: Huntsville, AL

Posts: 1,292

Time spent in forums: 2 Weeks 4 Days 10 h 31 m 53 sec
Reputation Power: 2331

Dell Inspiron 640m
* Mobile Intel 945GM Express Chipset
* Memory Sockets: 2

Mobile Intel 945GM Express Chipset Family
* 32-bit interface to address up to 4 GB of memory
* 256-Mb, 512-MB and 1-GB memory technologies supported
* There is no hardware lock to stop someone from inserting more memory than is addressable.

Based on this, the computer has a 1GB memory stick limitation due to a chipset limitation. That with only 2 sockets available makes the total limit 2GB.

Note that the chipset allows more memory to be installed than it can address. In other words for this laptop it should be limited to 2GB even if you have more memory than that installed.

The chipset can handle 4GB of RAM if you have 4 sockets available (4x1GB).
The chipset only uses 32-bit memory addressing so it should never see more than 4GB in any case.

Comments on this post

drumz0rz agrees!

krypton_ls agrees!

Snod Blatter agrees!

Trader Rating: 0 · #10

January 26th, 2009, 03:08 AM

akorpija

n00b DevH'er

Join Date: Jan 2009

Posts: 5

Time spent in forums: 44 m 19 sec
Reputation Power: 0

Thanks MisterEd good answer
Still itneresting that it sees the 4 gigs and uses 3.3 gigs

Cheers

Comments on this post

madhyena agrees: It's due to the 32-bit addressing.

Viewing: Dev Hardware Forums > HARDWARE > Memory > BIOS not using full 4 gigs of RAM despite 64 bit processor

« Previous Thread | Next Thread »

Thread Tools	Search this Thread
Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread:

Posting Rules
You may not post new threads You may not post replies You may not post attachments You may not edit your posts vB code is On Smilies are On [IMG] code is On HTML code is Off

View Your Warnings | New Posts | Latest News | Latest Threads | Shoutbox

Forum Jump

Free IT White Papers!

Create the Optimal Architecture for your Critical Applications
Warburton's the largest independently owned bakery in the UK faced a number of difficult challenges in providing the most robust yet efficient IT infrastructure for their organization's success. IBM's services combined with their xSeries servers created the perfect platform for their SAP environment with sufficient flexibility, and did so in very time effective fashion.

Five Best Practices for Deploying a Successful Service-Oriented Architecture
This white paper describes the benefits you can expect with SOA, and how IBM can help take your business there.

Gartner Magic Quadrant for Application Delivery Controllers
Gartner summarizes its view on Application Delivery Controllers, evaluates strengths and weaknesses of solutions, and provides Magic Quadrant reporting for a quick comparison across all vendors. Learn from Gartner how you can benefit from an all-in-one device like Citrix NetScaler that delivers the highest levels of availability, performance and security.

Knowledge is Power
What you don't know can hurt you, and is likely costing you money and increasing your security risks during an era of scarce resources. This white paper proposes six key strategies that enterprise security managers can use to improve their network defense posture.

Rationalizing the Multi-Tool Environment
The rationalized multi-tool approach is flexible, scalable and cost effective. It provides the necessary input to the IT service management business processes. It preserves prior investments in monitoring tools, empowers technologists to select the best tools with which to do their jobs, and enhances effective response to incidents.

More Free IT White Papers!