Single channel DDR2 533 ram - can you still buy

sherbie28

I have upgraded from XP to win 7 and pc is running a bit slow (2GB). My motherboard says it is single channel DDR2 533. Is the 533 MHz? I have looked online and my local shop that I usually buy bits and pieces from has the ram but it says 667/800. Does that mean I can't put it. in because it is a higher MHz? I was going to swap out the 2x 1gb sticks for 2x2gb. Thanks

Nilrem

You can usually use faster ram of the same generation, it'll just run slower.

IE in your example the 667/800 ram should be fine as it'll just not work as fast as it could.

emptybox

First of all make sure your motherboard can take more than 2GB of RAM.

But yes, you could use the higher speed RAM in it, but it might only run it at 533MHz depending on what the motherboard supports.

But you can certainly still buy DDR2 PC24200 533MHz RAM.
http://www.amazon.co.uk/Komputerbay-533MHz-PC2-4200-PC2-4300-Desktop/dp/B004LTAQIW/ref=sr_1_2?ie=UTF8&qid=1394906775&sr=8-2&keywords=ddr2+533
(note that is 240 pin RAM for a desktop PC. If it is laptop RAM you need look for 200 pin)

Quiet_Spark

Also be aware that there is no such thing as "dual channel" or "single channel" RAM, the operating mode of the RAM is set in the BIOS.

sherbie28

I've looked in the manual for my motherboard and it says: 'Due to chipset resurce allocation, the system may detect less than 4GB system memory when you install two 2GB DDR2 memory modules'

Does that mean if I put 4GB it will work as if it has 4GB in it or is there no point in me even upgrading? Thanks

spannerzone

sherbie28 wrote: »

I've looked in the manual for my motherboard and it says: 'Due to chipset resurce allocation, the system may detect less than 4GB system memory when you install two 2GB DDR2 memory modules'

Does that mean if I put 4GB it will work as if it has 4GB in it or is there no point in me even upgrading? Thanks

Probably refers to 32bit operating system memory allocation limitation like XP or Vista (although 64bit editions of those do exist) which can only 'see' and use up to about 3.5GB of ram regardless of whether you fit 4GB or 6 or 8 etc (often about 3.2GB as graphics card memory and pagefile resources also eats into this limit)

If you installed a 64bit OS like Win7 64bit then it'll most likely use all 4GB of ram or more if you installed more. The motherboard hardware may have a 4GB limit as well though.

I'd always recommend using Crucial Memory, use their memory scanner and it should show what options will work with money back guarantee if the scan info proves to be wrong (providing you use the scanner and keep the scans result number)

prowla

Some computers may be architected to use some of the address space for other things (eg. i/o), regardless of 32-bit or 64-bit OS.

And if the computer uses shared graphics, then that will take a chunk of it.

emptybox

prowla wrote: »

Some computers may be architected to use some of the address space for other things (eg. i/o), regardless of 32-bit or 64-bit OS.

And if the computer uses shared graphics, then that will take a chunk of it.

BIB that doesn't sound right?

As others have said, a 32 bit OS can only address a maximum of 4 GB, so everything - RAM, video RAM I/O etc has to fit into that.

But a 64 bit OS can address up to a theoretical maximum of approx 16 million terabytes (although that's limited by hardware and OS restrictions)
So all the extra stuff can be addressed beyond the reach of the physical RAM.
At least, that's my understanding?

prowla

emptybox wrote: »

BIB that doesn't sound right?

As others have said, a 32 bit OS can only address a maximum of 4 GB, so everything - RAM, video RAM I/O etc has to fit into that.

But a 64 bit OS can address up to a theoretical maximum of approx 16 million terabytes (although that's limited by hardware and OS restrictions)
So all the extra stuff can be addressed beyond the reach of the physical RAM.
At least, that's my understanding?

It depends how the hardware is architected. I had a Lenovo laptop with 4 GB and 64-bit Windows, but I didn't get 4 GB memory.

emptybox

prowla wrote: »

It depends how the hardware is architected. I had a Lenovo laptop with 4 GB and 64-bit Windows, but I didn't get 4 GB memory.

Well I take your point about shared graphics. Obviously that needs to use the RAM.
I've got 8GB RAM in one of my computers that has integrated graphics, and it says there is 7.73GB of usable RAM.

prowla

emptybox wrote: »

Well I take your point about shared graphics. Obviously that needs to use the RAM.
I've got 8GB RAM in one of my computers that has integrated graphics, and it says there is 7.73GB of usable RAM.

My current PC with 8 GB and 64-bit OS and a discrete graphics card says there is 7.87 GB usable.

I'll check out my work laptop later, which has Intel 4000 integrated graphics.

Unfortunately I don't have the Lenovo T500 I mentioned before anymore; it had a discrete graphics card, so something else was using the memory.

It occurs to me that some systems allow you to tune (some) memory settings in the BIOS.