Toshiba PX30t-C - Manual (Page 138)

Various system components (like the video adapter’s GPU and PCI
devices like Wireless LAN, etc.) require their own memory space. Since a
32-bit operating system cannot address more than 4 GB of memory, these
system resources overlap the physical memory. It is a technical limitation
that the overlapped memory is not available to the operating system. Even
though some tools might display the actual physical memory built into your
computer, the memory available to the operating system will still be
approximately 3 GB only.
Computers configured with a 64-bit operating system can address 4 GB or
more of system memory.
Hard Disk Drive (HDD) Capacity
1 Gigabyte (GB) means 10 9 = 1,000,000,000 bytes using powers of 10.
The computer operating system, however, reports storage capacity using
powers of 2 for the definition of 1 GB = 2
30 = 1,073,741,824 bytes, and
therefore shows less storage capacity. Available storage capacity will also
be less if the product includes one or more pre-installed operating systems,
such as Microsoft Operating System and/or pre-installed software
applications, or media content. Actual formatted capacity may vary.
LCD
Over a period of time, and depending on the usage of the computer, the
brightness of the LCD screen will deteriorate. This is an intrinsic
characteristic of LCD technology.
Maximum brightness is only available when operating in AC power mode.
Graphics Processing Unit (GPU)
Graphics processing unit (GPU) performance may vary depending on
product model, design configuration, applications, power management
settings and features utilized.
Total Available Graphics Memory is the total of, as applicable, Dedicated
Video Memory, System Video Memory and Shared System Memory.
Shared System Memory will vary depending on system memory size and
other factors.
Wireless LAN
The transmission speed over the wireless LAN and the distance over which
wireless LAN can reach may vary depending on surrounding
electromagnetic environment, obstacles, access point design and
configuration, and client design and software/hardware configurations.
The actual transmission speed will be lower than the theoretical maximum
speed.
User's Manual 7-14