PC-2700 (DDR-333) velocidad de bus ordenador RAM 2 GB de capacidad por módulo

How RAM Affects Performance

For most users, what really differentiates a slow computer from a fast one is how it responds to a keypress, not its actual processor speed. Often, adding 4 GB more memory can make a huge difference to your daily computing tasks.

What are Bus Speeds and Bandwidth?

Memory responsiveness is largely a factor of how fast the DDR can transfer data to the processor, a process which happens over a connection called the memory bus. Higher speed modules can transfer several GB of data every second so that the processor can keep its pipelines full. While bandwidth is related to bus speed, the two do differ:

• Bus Speed: Bus speed is the frequency of the connection between the processor and memory. For DDR333 that means a 166.6 MHz base clock that doubles to 333 MHz due to DDR. The bus speed not only affects bandwidth but also determines how frequently the system can send memory requests:
• Bandwidth: This measures the amount of data moved across the bus in a given period of time. For example, PC2700 memory offers a transfer rate of 2.7 GB per second per channel. Which also means that a 1 GB PC2700 DIMM needs over a third of a second to transfer data.

Where Can You Use PC2700 Memory?

PC2700 memory can appear anywhere from in a Proliant server to a gaming laptop. The standard supports both ECC and non-ECC memory in buffered and unbuffered modules. In most cases, different DIMMs will just snap right into the slot, but you do have to be careful as whether you have a desktop or laptop because those modules are not interchangeable:

• DIMM: The Dual In-Line Memory Module works for desktop computers and servers. It requires 2.5 Volts for signaling and has 184 pins with a single voltage notch to ensure it's installed in a compatible slot. Each package is 133.35 mm long.
• SODIMM: The Small Outline DIMM works in laptops. Each 200-pin SODIMM uses the same 2.5-Volt signaling protocol as larger modules but does not support ECC or other data integrity options.

Choosing DDR

There are several things to look for when choosing DDR for a computer. Anyone with a dual channel machine should consider a 2 GB kit as opposed to a 2 GB stick as that will enable the full dual channel mode. Also be aware that mixing PC2700 with PC3200 will drop the DDR clock to 333 MHz as the memory subsystem always runs at the highest speed compatible with all sticks, not that of the fastest stick. In most cases, you're better off with more capacity than faster RAM though. The performance drop of 66 MHz is going to be less of an issue than the performance drop of going from memory to the hard drive.