Web Development



I need BIOS support for more than 4GB RAM...

By PESK, mbcs, mcse, mcitp, sts ·
I have a Toshiba Satellite Pro L40-PSL4BE and the latest Toshiba-OEM BIOS version (http://eu.computers.toshiba-europe.com/innovation/download_bios.jsp) only supports a maximum of 3GB RAM.

I am running Windows 7, 32-Bit, Enterprise and I am finding that I am constantly needing more than the 3GB I currently have installed.

Is there a BIOS (custom, or otherwise) version out there that will allow me to install and run more than 3GB of RAM?

P.S.-Please do not reply with "Install 4GB and see what happens..." or "Windows will support more than 3GB..." or "GO to the Toshiba website..." or "Buy a newer model." type posts. RTFQ! Properly...

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All Answers

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Well you have ruled out most sensible options

by OH Smeg Moderator In reply to I need BIOS support for m ...

As for a Custom BIOS I'm not even sure that this will be of any help as it depends on the Chip Set of the M'Board NB as to what it can support/map.

If the Chip Set can not Map more than 3 GIG of RAM then shelling out for a Custom BIOS isn't going to help at all. But no matter if you want to try I believe that BIOS MAN do custom BIOS's so I would suggest you contact them for a Guesstimate


Personally I've never used them for this but for replacement BIOS Chips they are very good and I have bought from them on numerous occasions in the past with very good service and results.


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Thanks for the prompt response, Col...

I've always been of the opinion that laptops are a niche product, since they can only be upgraded 'so far'... Until, I had reason to, and managed to upgrade the processor, WLAN to 'N'-type with an added third antenna and I also added an internal USB mod (for ReadyBoost) in place of the modem and now I'm laptop-primary-user, thru' and thru'. This, even though I was already primarily using the laptop and had already upped my HDD to 500Gb. I have desktops dotted around the place, but I will never be without my 'lappy'...

I will look at BIOS man and see what they have to offer...

Many thanks.

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3.3 GB

by Enforcer Drive In reply to I need BIOS support for m ...

Win7 will show that you have 4GB installed but it will never use more that 3.3GB. It will actually show if you have 8GB installed but still it won't use more than 3.3GB. I guess 64bit would be the best option, hopefully your apps can run on 64 bit.

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I hate to be rude...

by PESK, mbcs, mcse, mcitp, sts In reply to 3.3 GB

...but you've done exactly what I asked not to be done. You haven't RTFQ!


Sorry to be so abrupt.

And by the way, even though Win7 will only 'see' 4GB RAM, using PAE will allow for this limitation to be surpassed.

Thank you for your input.

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Is it worth it?

by Enforcer Drive In reply to I hate to be rude...

Sorry, I didn't realise you were going to all this trouble to unlock 300MB of Ram, good luck.

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I have no problem being rude.

by santeewelding In reply to I hate to be rude...

You have a corncob up your ***.

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by boxfiddler Moderator In reply to I hate to be rude...

you don't hate to be rude. Your OP was rude.

'RTFQ... Properly.'

Help me, but only if... Bah.

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PAE Won't Work Either

by TheChas In reply to I need BIOS support for m ...

As you are running the 32-bit version of Windows 7, even PAE will not get you past the 4GB limitation.


"Microsoft Windows implements PAE if booted with the appropriate option, but current 32-bit desktop editions enforce the physical address space within 4GB even in PAE mode. According to Geoff Chappell, Microsoft limits 32-bit versions of Windows to 4GB due to a licensing restriction[2], and Microsoft Technical Fellow Mark Russinovich says that some drivers were found to be unstable when encountering physical addresses above 4GB.[3]. Unofficial kernel patches for Windows Vista 32-bit are available[dubious ? discuss] that break this enforced limitation, though the stability is not guaranteed."

Even if you could get past the 3GB limitation with a BIOS change, the physical hardware in the chip-set and system board is still very apt to limit the amount of installed RAM that will work.

Now, the reason why Toshiba (wisely) limits the system to 3GB of installed RAM is that the extra 1GB of upper memory basically draws power but is not usable by Windows.

As Colin stated, many chip-sets do not have the hardware implemented to support more than the full 4 GB of addressable RAM even if you could invoke PAE mode.

That upper 1GB is where the physical addresses for your video card, system bus and system devices resides. It's not just the BIOS that would need to be revised to have access to more than the 3GB of RAM that Toshiba limits you to. You would need to restructure how the physical address lines are routed on the system board.

Your options to improve performance of memory intensive applications include:

Set virtual memory to a minimum of 2X installed RAM with no maximum.

Use a fast USB flash drive as a ready-boost device.

Limit the number of applications that run and load at startup.

Still, the best way to resolve the memory limit for 32 bit versions of Windows is one you excluded. Move to new hardware with full 64 bit support.


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That's what I found too...

by AnsuGisalas In reply to PAE Won't Work Either

Specifically "Certain 32-bit versions of Windows Server running on x86-based systems can use PAE to access up to 64 GB or 128 GB of physical memory, depending on the physical address size of the processor. For details, see <a href=http://msdn.microsoft.com/en-us/library/aa366778(v=vs.85).aspx>Memory Limits for Windows Releases</a>."
<font color="FFFFF">RTFA</font>

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