Memory: Dell Dimension XPS P133s, P166s, and P200s

Memory Installation Guidelines | DIMM Configurations | Removing/Installing Memory | Upper Memory Map | Conventional Memory Map

Memory Installation Guidelines

NOTES: The only 32-MB SDRAM DIMMs validated for use in this computer are the following:
  • Samsung KMM366S403AT1-G2
  • Hitachi HB526A464EN-10
  • Samsung KMM366S403AT-G2
  • Toshiba THMY644021AEG-12A

The system may not recognize other 32-MB SDRAM DIMMs and may fail POST.

When the system memory size is increased above 64 MB in a system with the Intel® Pentium® VX chip set, the system slows down. The problem is the cache limits of the chip set. The second-level (L2) cache can store (cache) memory only for accesses made in the lower 64 MB of main memory due to the size of the cache tag. If more than 64 MB is installed in the system, any memory access to data above the 64 MB is not cached. The system runs cacheless for memory accesses. The Microsoft® Windows® operating system uses pages of memory throughout the entire memory space so some accesses fall above the 64-MB region, which causes a decrease in performance. In effect, instead of getting a performance gain for adding more memory to a base 64-MB system, in many instances the performance is slower.

Additionally, many games that use MS-DOS® extenders are loaded at the top of the memory space so all accesses to the code are cacheless.

DIMM Configurations

The DIMM sockets are labeled "BANK0" and "BANK1" on the system board.

BANK0 BANK1 Total
16 MB empty 16 MB (SDRAM)
16 MB 16 MB 32 MB (SDRAM)
32 MB empty 32 MB (SDRAM)
32MB 16 MB 48 MB (SDRAM)
32 MB 32 MB 64 MB (SDRAM)

Removing/Installing Memory

  1. Remove the computer cover.
  2. To remove a DIMM, carefully press down on the ejector tabs at each end of the socket.
  3. To replace or reinstall a DIMM, align the notches in the DIMM edge connector with the socket. Carefully press one end of the DIMM and then the other into the socket until the DIMM is seated; then secure the DIMM using the 2 ejector tabs at each end of the socket.
CAUTION: Pressing on the center of the DIMM may damage the DIMM.

Upper Memory Map

Location Size Description
00100000-008000000 127 MB Extended memory
000F0000-000FFFFF 64 KB System BIOS
000EE000-000EFFFF 8 KB FLASH boot block
000ED000-000EDFFF 4 KB Plug and Play configuration area
000C8000-000ECFFF 148 KB Available (except for PCI memory block area)
000C0000-000C7FFF 32 KB Video BIOS
000A0000-000BFFFF 128 KB Video RAM
00080000-0009FBFF 127 KB Extended conventional memory
00000000-0007FFFF 512 KB Conventional memory

Conventional Memory Map

Segment Address Range Use
0 00000h-003FFh Interrupt vector table
  00400h-004FFh BIOS data area
  00500h-005FFh MS-DOS® work area
  00600h-0FFFFh User memory
1 10000h-1FFFFh User memory
2 20000h-2FFFFh User memory
3 30000h-3FFFFh User memory
4 40000h-4FFFFh User memory
5 50000h-5FFFFh User memory
6 60000h-6FFFFh User memory
7 70000h-7FFFFh User memory
8 80000h-8FFFFh User memory
9 90000h-9FBFFh User memory
  9FC00h-9FFFFh PS/2-mouse data area