Installed 4G RAM on 15.4'' T61, but puzzled...

Hello, I got a 15.4'' T61 a few days from Lenovo. Today, I got the 4G Patriot RAM from outpost.com.

I installed them on my computer based on the instructions on the IBM site.

After putting memory in the computer, I started the machine and went to ThinkVantage->Access BIOS and noticed that the Installed Memory: 4098M

After this procedure, I did a few startups and shutdowns and now I am puzzled by one number.

After each startup, I went to Settings->Control Panel->System and I noticed the following under the line with "T7700 @ 2.40GHz":

ddd, 2.99GB of RAM

"ddd" changes for each startup. I got numbers such as 2.39GHz, 1.79GHz, 789MHz. No pattern.

Can anybody explain what this number is and what value it should be. The memory I bought from outpost.com is:

DDR2 2GB PC5300 667M SO-D PAT NOTEBOOK MEMORY


Also based on the above, is the memory upgrade normal?


I got 2 dimms from outpost.com and noticed that one memory box seems opened before.

I have no memory upgrade experience before and this is my first Thinkpad.


Your help is truly appreciated.

Thanks!!!

EDIT: I have Win XP Pro.

 

32bit operating systems have 4 gigs of address space. Theoretically, this means you can have 4 gigs of RAM. But all memory-mapped devices (i.e. video cards) and BIOS ROMs take up some of this address space.

So, only what is left after those things is allocated to RAM. I think it is generally advisable to not get >3gig of RAM with a 32bit OS because the rest is a waste.

Some reading:
http://www.codinghorror.com/blog/archives/000811.html

 

The speed changing is because I bet you're on battery power when you reboot, and the machine will use power management to lower the CPU frequency to save battery power.

What OS have you got installed? Is it Vista 64bit or 32bit?

 

The "ddd" numbers are most likely the current effective clock speed of the processor, since the santa rosa chipset clocks down the processor when it's not being used. As for the 2.99GB, well it sounds like you're using a 32-bit OS.

 

>>only what is left after those things is allocated to RAM.

Thanks. I understand this. My question is about something else.

I am using Win XP pro.

 

Install a live CPU monitoring program, and you will see the processor clock speed jump up and down based on usage. This is done to save battery.

 

Thanks.

So the "ddd" changing situation is normal?

 

I know I am going to get less than 4 GB RAM on my T61/XP system. I also wanted to know how much memory I should have.

 

Yes. I am pretty sure that the the System utility only gets the clock speed from the processor once (when you open the program).

Look around online for a program called SuperPi. It is meant to stress your processor and run it at full clock speed by calcualting pi. Run that to 1 million decimal places, and Google your processor and compare it to times that yours or similar processors scored, and you should see it doing just as well.

Otherwise, run it, then open System and see what it says for your clock speed.

Or do what I said earlier and get a live processor clock monitor and watch it jump around with changing activity.

 

3 gigs assuming you get the 32bit version (which is standard). Best performance you can get and you aren't wasting any.

 

Thank you very much for your input. I will do the SuperPi tests.

FYI: I just connected the power and noticed that the ddd jumps 2.39GHz.

 

Sounds like the memory upgrade is a success.

Thank you guys, you are awesome!

Will do the SuperPi tests if necessary.

 

I wouldn't even bother. I'm sure it's fine.