RAM,a question.

[swanseadave]

Why is it that 32bit Windows doesn`t use all the memory that`s installed?
let me explain
I`ve just installed a matching pair of 1gb modules but system information shows only 1.93gb,not 2gb

there must be a logical explanation shirley?

[Dorset_Mike]

Mine's a little better than that, 2GB reads as 2038, on me other machine 1Gb reads as 1014, daft innit.

The other intriguing thing is that last week both were running on 512MB, yet now running the same applications both are using around 750MB, how did they manage before?

[Chris Cool]

It probably needs to use some of the available memory to keep track of the files plus it will have checking and maintenance included to keep the memory in tip top condition

[chris_p]

Why is it that 32bit Windows doesn`t use all the memory that`s installed?
let me explain
I`ve just installed a matching pair of 1gb modules but system information shows only 1.93gb,not 2gb

there must be a logical explanation shirley?

There is an explanation.

It's becuse computers work in base2 numbering, not decimal. 8 bits are a byte and so on... So 1 KB is 1,024 bytes (in base2 thats 2 to the 10th), and 1MB is 1,048,576 bytes (2 to the 20th) and a gigabyte is 2 to the 30th (1,073,741,824 bytes).

Us humans tend to think in decimals so to you and me 2GB should be 2,000,000,000 bytes and thats eaxctly what your RAM has.
In base2 numbers that's 1.93GB. For your computer to register 2GB of functional RAM you'd actually have to put 2,147,483,648 bytes worth in it (or about 2.15GB)

[beejaybee]

I`ve just installed a matching pair of 1gb modules but system information shows only 1.93gb,not 2gb

Likely the "missing" 64MB memory is being allocated to the video chip & is not therefore available for program / data storage.

[Dorset_Mike]

There is an explanation.

It's becuse computers work in base2 numbering, not decimal. 8 bits are a byte and so on... So 1 KB is 1,024 bytes (in base2 thats 2 to the 10th), and 1MB is 1,048,576 bytes (2 to the 20th) and a gigabyte is 2 to the 30th (1,073,741,824 bytes).

Us humans tend to think in decimals so to you and me 2GB should be 2,000,000,000 bytes and thats eaxctly what your RAM has.
In base2 numbers that's 1.93GB. For your computer to register 2GB of functional RAM you'd actually have to put 2,147,483,648 bytes worth in it (or about 2.15GB)

I strongly doubt your explanation, unless the industry has done a major rethink of its terminology in the last year or so without telling anybody, I suspect you will find that 2GB is still 2,147,483,648 bytes. The post which follows yours has a far more feasible explanation, in quoting video ram as the culprit. I know my machines have on board video and use a chunk of system RAM for it.

[BigWill]

I`ve just installed a matching pair of 1gb modules but system information shows only 1.93gb,not 2gb

Likely the "missing" 64MB memory is being allocated to the video chip & is not therefore available for program / data storage.

Yep, I'd go with that explanation. "On board" graphics chip "stealing" 64mb of the system memory to use for the graphics.

BigWill

[chris_p]

2GB is still 2,147,483,648 bytes. But that's not what you buy. You buy 2,000,000,000.

Thats why (for example) a terabyte HDD has an available capacity of 931GB.

Always has been and always will be.

[Dorset_Mike]

Having worked for 45 years in electronics, including teaching microprocessor techniques, I'll stick with my version, we'll just have to agree to differ on that one.

[swanseadave]

Hmmmm,I`ve followed this thread with great interest since posing the question.
I think I am more inclined towards the thoughts of Cool Hand Chris,BJB and Big Will.It makes sense.I started to lose the will to live trying to make sense of chris_p`s explanation.

Thanks to all.
Cheers

[Crosstalk]

I too will go with the on board graphics stealing 64MB. This would leave you with 1984 of the 2048 MB installed. Converting the 1984 MB to gigabytes using 1024 MB in a GB would give:

1984/1024 = 1.9375. In my book that would be 1.94 GB, but I'll assume it just got truncated rather than rounded.

However, before we all get too dismissive of chris_p's rather convoluted suggestion, although it's total BS when it comes to RAM, he does have a valid point when it comes to hard drives - the marketing departments pulled a blinder at some point and convinced everyone that a GB was indeed 10^9 bytes (rather than 2^30). Don't believe me? Check out this this seagate PDF and look at the note at the bottom of the table.

Quote from pdf:

One gigabyte, or GB, equals one billion bytes and one terabyte, or TB, equals one trillion bytes when referring to hard drive capacity.

[swanseadave]

Ahhh,in that context it does make sense.

Cheers

[Smudger79]

Ahhh,in that context it does make sense.

Cheers

Yes, but most of the time where you see 1Kb, you should read 1024 bits.
This specifically has to say that 2Gb is 2 billion bits because this is not the norm.

[BiGnoSe]

The jury is out for me on the numbers but my opening punt on this is to consider the structure or formatting of the memory and hard disks.

My limited knowledge is that RAM is added up in base 2 but is rounded down for understandability.

My guess for the difference of numbers for memory and hard drives is the formatting. If I covered a wall with pigeon holes to store things in, the surface area of the wall would be less because of what was taken up by the pigeon holes. Hence why a 1TB drive shows only as 931Gb.

64Mb stolen by graphics? Possibly, but windows will 'steal' hard drive space a "swap file" space. This is a budget version of memory utilising hard disks not volatile memory.

Confused or concur?
You decide!