different ram/gpu size shown in different softwares

[cingo]

hi friends,

this is a weird observation..i dont know why. please explain.

i have 2 GB of RAM in 2 slots = 4GB total ( 3.85 to 3.9 GB)
in bios i set shared by gpu = 256MB

so logically the system should show nearly 3750MB or near 3650MB (i know it is never round figures)

please see the screen shots of
system properties, GPUZ and dxdiag .. all showing different values
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Processor
Model : AMD Phenom(tm) 8650 Triple-Core Processor
Speed : 2.3GHz Cores per Processor : 3 Unit(s)

Mainboard : Asus M3N78-EM

Chipset
Model : AMD F10h Athlon 64/Opteron/Sempron HT Hub
Front Side Bus Speed : 2x 1.8GHz (3.6GHz)
Total Memory : 4GB DIMM DDR2
Memory Bus Speed : 2x 333MHz (666MHz)

Memory Module(s)
Memory Module : Transcend JM800QLU-2G 2GB DIMM DDR2 PC2-6400U DDR2-800 (5-5-5-18 3-23-6-3)
Memory Module : Transcend JM800QLU-2G 2GB DIMM DDR2 PC2-6400U DDR2-800 (5-6-6-18 3-24-6-3)

Video System
Video Adapter : NVIDIA GeForce 8300 (24 SP 1.5GHz, 256MB DDR2, Integrated Graphics)

Graphics Processor
Adapter : NVIDIA GeForce 8300 (8SP 1C 1.5GHz, 253.7MB, Integrated Graphics)

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[troublesooter]

Very typical problem ,

Lets start with simple calculation 3328MB = 3.25 GB,
ur DXDIAG shows that ur card can support upto 512 MB of RAM and u say ur working RAM is approx 3.85GB working.

In ur GPU-Z it shows the amount of memory allocated to ur GPU by you i.e. 256 MB.

Now lets add amount of memory ur first page of dxdiag shows i.e 3328MB and approx memory shown by dxdiag i.e 512MB that's equals 3840MB i.e 3.75 GB.

Here we can see u're at loss of 256MB or 128 MB at every stick of ur RAM. I'm not sayin this a final solution.

Overall all I can justify is that ur 256MB memory is capped by XP