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4GB kit (2GBx2) DDR2 PC2-6400 Unbuffered NON-ECC 1.8V 256Meg x 64

Image for 4GB kit (2GBx2) DDR2 PC2-6400 Unbuffered NON-ECC 1.8V 256Meg x 64 from Crucial USA
  • Brand: Crucial
  • Form Factor: UDIMM
  • Module Size: 4GB kit (2GBx2)
  • Warranty: Limited Lifetime
  • Specs: DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • 1.8V • 256Meg x 64 •
  • Series: Crucial
  • Part number: CT2KIT25664AA800
More information

Image for 4GB kit (2GBx2) DDR2 PC2-6400 Unbuffered NON-ECC 1.8V 256Meg x 64 from Crucial USA
Kit Qty: 2
Speed: 800MHZ
Tracer: False
Voltage: 1.8V
DIMM Type: Unbuffered
Bullet Features: Increases system performance

240-pin DIMM

240-pin DIMM for DDR2 memory" border=
Approximately 5.25 in. by 1.18 in. (133.35 mm by 30 mm)

A dual inline memory module (DIMM) consists of a number of memory components (usually black) that are attached to a printed circuit board (usually green). The gold pins on the bottom of the DIMM provide a connection between the module and a socket on a larger printed circuit board. The pins on the front and back of a DIMM are not connected to each other.

240-pin DIMMs are used to provide DDR2 SDRAM memory for desktop computers. DDR2 is a leading-edge generation of memory with an improved architecture that allows it to transmit data very fast.

Each 240-pin DIMM provides a 64-bit data path (72-bit for ECC or registered or Fully Buffered modules). (The Ballistix™ and Ballistix Tracer™ high-performance memory do not come in 72-bit or registered modules.)

Standard DDR2 240-pin DIMMs are available in DDR2 PC2-3200 SDRAM, DDR2 PC2-4200 SDRAM, DDR2 PC2-5300 SDRAM, and PC2-6400 SDRAM.

To use DDR2 memory, your system motherboard must have 240-pin DIMM slots and a DDR2-enabled chipset. A DDR2 SDRAM DIMM will not fit into a standard SDRAM DIMM socket or a DDR DIMM socket.

The number of black components on a 240-pin DIMM can vary, but it always has 120 pins on the front and 120 pins on the back, for a total of 240. 240-pin DIMMs are approximately 5.25 inches long and 1.18 inches high, though the heights can vary. While 240-pin DDR2 DIMMs, 184-pin DDR DIMMs, and 168-pin DIMMs are approximately the same size, 240-pin DIMMs and 184-pin DIMMs have only one notch within the row of pins. The notch in a 240-pin DDR2 DIMM is closer toward the center of the module.

Ballistix and Ballistix Tracer 240-pin DIMMs

Our high-performance Ballistix 240-pin DIMMs come in DDR2 PC2-5300 SDRAM, DDR2 PC2-6400 SDRAM, and DDR2 PC2-8000 SDRAM. The Ballistix Tracer illuminated, activity-indicating high-performance 240-pin DIMM comes in SDRAM, DDR2 PC2-6400 SDRAM, and DDR2 PC2-8000 SDRAM

For more information about the Ballistix memory line, please visit the Ballistix section of our Web site.

Ballistix 240-pin DIMM
Ballistix 240-pin DIMM for DDR2 memory" border=

Approximately 5.25 in. by 1.18 in. (133.35 mm by 30 mm)

Ballistix Tracer 240-pin DIMM
Ballistix Tracer 240-pin DIMM for DDR2 memory" border=

Approximately 5.25 in. by 1.18 in. (133.35 mm by 30 mm)

OID: 03BB4DE4A5CA7304
PR file path: /pwr/96v439cu/inline/07/77/03BB4DE4A5CA7304-en_US-1-questions.html

Do you have questions about this product?

get answers from real customers and in-house experts with AnswerBox.

4 Questions | 3 Answers
Displaying questions 1-4
  • Q:

    is there support for Serial Presence Detect (SPD)
    Asked on 9/4/2011 by Jeff

    1 answer

    • Staff Reviewer


      Serial Presence Detect (SPD) is a memory hardware feature that makes it possible for the computer to know what memory is present, and what timings to use to access the memory.

      In order for a memory module to support SPD, the JEDEC standards require certain parameters to be placed in the lower 128 bytes of an EEPROM located on the memory module (the SPD chip). These bytes contain timing parameters, manufacturer, serial number and other useful information about the module.
      The BIOS uses this information to determine what speed and timings to run the memory at. It is also possible to enter the BIOS and manually improve these speeds and timings, this is called overclocking.
      As the memory modules may not support tighter timings, overclocking can lead to crashes and system failure. It can also reduce the lifetime of the modules as they often run at higher voltages and therefore higher temperatures than they were designed for.

      Answered on 9/5/2011 by Crucial Support from Meridian, Idaho
  • Q:

    does this memory module support serial presence detect (SPD)data structure?
    Asked on 8/4/2011 by neal from houston, tx

    0 answers

  • Q:


    Is this compatible with Dell Optiplex 740?
    This looks like having the exact same spec.

    Thank you.
    Asked on 7/2/2011 by holala from WA

    1 answer

    • Staff Reviewer


      Yes, this memory kit will be fully compatible with the Optiplex 740.

      Answered on 7/4/2011 by Crucial Support from Meridian, Idaho
  • Q:

    can i use this memory type for my Dell Dimension 8250 desktop?
    Asked on 6/10/2011 by sang from anaheim, california, us

    1 answer

    • Staff Reviewer


      No, unfortunately not. Your computer uses RDRAM, also known as Rambus(R) memory, on 184-pin RIMMs. Unfortunately, Crucial does not carry RDRAM. For further information on Rambus(R) RDRAM, please visit our FAQs at

      Answered on 6/16/2011 by Crucial Support from Meridian, Idaho
Displaying questions 1-4

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