Incorrect. 32bit system can only address ~4GB, but with PAE (Physical Address Extension) it can address up to 64GB. Your CPU must have the PAE flag. Check it:
So the array is able to address a maximum of 8GB in theory, but it is limited by the memory controller (BIOS):
So in fact: Your hardware can theoretically use 8GB, but limited by controller, which only allows a maximium of 4GB and 2GB for each module.
It’s like you have an 8 lane highway, but since not enough traffic lights have been installed, 4 of them are closed to avoid accidents.
Probably you can increase the possible memory by switching some options in the BIOS (slower RAM, but more capacity?), but if that is not possible, then you are hard limited to 4 GB maximum by the BIOS.
root@jesuslinux:/home/jesuslinux# dmidecode -t bios
# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.4 present.
Handle 0x0000, DMI type 0, 24 bytes
Vendor: American Megatrends Inc.
Release Date: 08/21/2007
Runtime Size: 64 kB
ROM Size: 1024 kB
ISA is supported
PCI is supported
PNP is supported
BIOS is upgradeable
BIOS shadowing is allowed
ESCD support is available
Boot from CD is supported
Selectable boot is supported
BIOS ROM is socketed
EDD is supported
5.25"/1.2 MB floppy services are supported (int 13h)
3.5"/720 kB floppy services are supported (int 13h)
3.5"/2.88 MB floppy services are supported (int 13h)
Print screen service is supported (int 5h)
8042 keyboard services are supported (int 9h)
Serial services are supported (int 14h)
Printer services are supported (int 17h)
CGA/mono video services are supported (int 10h)
ACPI is supported
USB legacy is supported
LS-120 boot is supported
ATAPI Zip drive boot is supported
BIOS boot specification is supported
Targeted content distribution is supported
BIOS Revision: 6.24
Firmware Revision: 188.11
Handle 0x0018, DMI type 13, 22 bytes
BIOS Language Information
Language Description Format: Abbreviated
Installable Languages: 3
Currently Installed Language: en|US|iso8859-1
My system is 64bits. It came with Win Vista 32bits back in 2007/2008.
I tried to check if there’s BIOS updat but to no avail.
Toshiba sites no longer have info about BIOS on this product.
So I can upgrade to 2x 2GB DDR2 with no issues?
There was always this doubt. But it makes sense since one slot has a 2GB stick.
I have to look for a 2GB DDR2 stick then!
Once I get to the 4GB RAM do I have to change the swap file from the current 3GB to 4GB?
I recently changed the drive to 120GB SSD and what a difference from 80GD HDD.
I’m amazed with this old Toshibas still running since 2007. It was not in use for some years until I discovered Linux some time ago with Manjaro.
I reminds me of old Mercedes cars lol!
Might be worth trying the 2x4GB option too.
This official/unofficial max ram support discrepancy was quite common in macs around 2010. My 2009 mbp was sold as 4GB max but does in fact support 8GB.
The ‘old Mercedes’ analogy isn’t even giving full credit to some of those machines. Not only do they keep working like when they were new, they actually will outperform themselves by a huge margin after ssd, ram and battery upgrades.
Yes, I upgraded a couple of those for family members back in the day. With 8GB and a SSD they’re still very usable today for light tasks.
However, those models used DDR3. The previous gen Macbook Pro (pre-Unibody) is a lot closer to what the OP has. Those were DDR2 667Mhz and officially they supported either 3GB (2+1) or 4GB (2+2) depending on exact model. Unofficially it was possible to use 4GB (2+2) in all of them and 6GB (4+2) in the later ones.
On the earlier models 4GB would work no problem but you’d actually only get something like 3.3-3.5 GB. Reason being that some of the 4GB address range had to be reserved for system device I/O. I strongly suspect that this is what the OP will see with 4GB (I’m assuming that his motherboard has some variant of the Intel 945 chipset).