Difference between DDR RAM and XDRAM

[Bigga Lexx]

Hello.
I'm doing a presentation on the ps3 and RAM for my computer is different than RAM from game consoles,I'd like to know the differences between memory XDram which team ps3 and DDR2 with most pc.
Type the 256 XDRam the ps3 + 256 MB GDDR3, what it's worth facing 2 GB DDR2?

Thanks

[Joshua]

So a little explanation on the RAM and in particular the DDR RAM:
DDR SDRAM (usually just say DDR) is an evolution of the SDR SDRAM (often simply called SDRAM), which appeared with the Pentium and Pentium II. The principle of SDRAM is to operate with a clock, the clock is there to clock the functioning of memory (read, write, refresh, activation line ...), all timings are expressed in number of cycles clock (like the famous CAS Latency).
SDR SDRAM on when you read or write when there is only given for each clock cycle, the data being written or read in groups of 4, 8 ...called bursts.
DDR SDRAM on the difference is that there are 2 data that follow each clock cycle, and without changing the clock on double the flow of data, the bursts are 2x faster. There are several generations of DDR SDRAM: DDR1, DDR2, DDR3.the only difference from the outside is the clock frequency is increasing and the supply voltage increasingly low (2-3 over small things, but we will not go into details).
The GDDR (1, 2, 3 ...) are specific to DDR SDRAM graphics cards but very close to the DDR in their operation (just a few enhancements to further improve the perfs in the case of use with a graphics processor)
The trap when it comes to DDR is to mix the frequency of the clock with the data (which is double), a DDR2-800 has a clock speed of 400MHz.

For XDRAM or XDR DRAM is a memory developed by Rambus, the X meaning "Extreme". Its uniqueness is that it can transfer up to 8 data per clock cycle! The clock is similar to DDR2 and DDR3 (between 400MHz and 1066MHz), we easily imagine the difference in performance with them (up to 4x faster). In fact technologically it is closer to the tech as PCI Express, with a variable number of son called "lane" working with high frequency (on the PCI Express clock is 100MHz, but the data will 25x faster here data will 8x faster but the clock frequency is higher)

Type the 256 XDRam the ps3 + 256 MB GDDR3, what it's worth facing 2 GB DDR2?

Quantity and frequency of memory are 2 different things, we can not compare them. The amount of memory is not directly linked to performance, a hard drive 2x bigger is not necessarily 2x faster, he just 2x more space, it is the same for memory, you just need the right amount compared to the needs: neutral:
As against the frequency is directly linked to performance, memory with a higher frequency 2x is of course 2x more efficient, provided that the component that uses (GPU, CPU, controller ...) is capable of collecting such performance (which is not necessarily the case on DDR3 motherboards for Intel Core2 for example)

[Bigga Lexx]

Thank you very much for giving me information in detail.
Xdram therefore may contain less data but it can move more information per clock cycle, it compensates for this low a little storage space is not it?

[Joshua]

what I said just above, frequency and amount of memory has nothing to do, one can not compensate the other. If only 256 is simply because they can not save more if it's too expensive, they have no choice. It therefore requires to manage the data stored in order not to exceed 256.

If the speed of RAM then offset the amount would suffice to place only 1GB of RAM in a PC but to take the faster RAM, or it does not, if a program needs 2GB of RAM regardless of the type RAM, if not quite so good row.