Ddr Sdram Module

Ddr Sdram Module What means 1.0GB, 333MHz, PC2700 DDR-SDRAM Dual In-Line Memory Module? I have a laptop Hp Pavilion ZV6024ea, and the memory upgrade recomendation is 1.0GB, 333MHz, PC2700 DDR-SDRAM...


Ddr Sdram Module

What means 1.0GB, 333MHz, PC2700 DDR-SDRAM Dual In-Line Memory Module?

I have a laptop Hp Pavilion ZV6024ea, and the memory upgrade recomendation is 1.0GB, 333MHz, PC2700 DDR-SDRAM Dual In-Line Memory Module. I know that 1.0 GB is capacity, 333Mz is speed, but what it means PC2700 DDR-SRDRAM? I´ve found other memory cards with PC5400 and DDR2, can i use them?
And what it means Dual In-Line?

PC2700 is an industry-wide marketing description for the data transfer rate of that memory. The base memory chips used on the module can transfer data at 333 M bits per second per pin (data pin.) Since that module has a 64-bit wide data bus (= 8 bytes wide), the module can transfer 8 x 333 Mbps or 2666 M-Bytes per second. Rounding it up, you get 2700 MB/second, used primarily on PCs.

DDR-SDRAM means Double Data Rate – Synchronous Dynamic Random Access Memory. DDR means the data into or out of each chip is transferred on both edges of the clock input to the chip — Double Data Rate. (Older SDRAM technology can only transfer data on one clock edge, Single Data Rate.)

DDR2 is the second-generation of DDR architecture. Performance was increased because the data speeds (2X clock rates) were increased over DDR. But the memory’s power supply and I/O voltages were reduced to control power consumption and maintain reliability and process compatibility. And the data bus has been improved for better signal intregrity.

You cannot put DDR2 modules into a DDR socket – the voltages, bus handshakes, commands, and even pinouts are all different. They are not interchangeable or compatible.

Dual In Line is the mechanical configuration of the memory module signals.

Back in the day, memory modules were Single Inline Memory Modules (SIMMs), with all signals connected on only one side of the memory module. There were 36 contacts on each side – front and back. (The signals were electrically connected on the front and backside, so the signals were duplicated.) These were generally FPM (Fast Page Mode) and EDO (Extended Data Out) asynchronous DRAM based modules. The data bus was only 32 bits wide to match the Intel 386 and 486 CPUs.

When SDRAMs came on the scene, more signals were needed to permit a larger address range, to provide clocking signals as well as more power and ground pins. The system data bus increased to 64 bits (72 bits for servers.) So the memory module was redesigned to use all the signals independently on both the front and back of the connector. It was called the Dual Inline Memory Module, and provided 168 contacts.

When the industry transitioned to DDR, more pins were added, but the DIMM configuration continued. The DDR module provides 184 contacts, while the DDR2 module uses 240 contacts.

Coming up next: DDR3 – the 3rd generation DDR memory architecture.

Leave a Reply