10-08-2012, 04:24 PM
DRDRAM
[attachment=31013]
Direct Rambus DRAM or DRDRAM (sometimes just called Rambus DRAM or RDRAM) is a type of synchronous dynamic RAM. RDRAM was developed by Rambus inc., in the mid-1990s as a replacement for then-prevalent DIMM SDRAM memory architecture.
RDRAM was initially expected to become the standard in PC memory, especially after Intel agreed to license the Rambus technology for use with its future chipsets. Further, RDRAM was expected to become a standard for VRAM. However, RDRAM got embroiled in a standards war with an alternative technology - DDR SDRAM, quickly losing out on grounds of price, and, later on, performance. By the early 2000s, RDRPC main memory
The first PC motherboards with support for RDRAM debuted in late 1999, after two major delays. RDRAM was controversial during its widespread use by Intel for having high licensing fees, high cost, being a proprietary standard, and low performance advantages for the increased cost. RDRAM and DDR SDRAM were involved in a standards war. PC-800 RDRAM, which operated at 400 MHz and delivered 1600 MB/s of bandwidth over a 16-bit bus. It was packaged as a 184-pin RIMM (Rambus in-line memory module) form factor, similar to a DIMM (dual in-line memory module). Data is transferred on both the rising and falling edges of the clock signal, a technique known as DDR. For marketing reasons the physical clock rate was multiplied by two (because of the DDR operation); therefore, the 400 MHz Rambus standard was named PC-800. This was significantly faster than the previous standard, PC-133 SDRAM, which operated at 133 MHz and delivered 1066 MB/s of bandwidth over a 64-bit bus using a 168-pin DIMM form factor.
RDRAM memory with integrated heat spreader
Moreover, if a mainboard has a dual- or quad-channel memory subsystem, all of the memory channels must be upgraded simultaneously. 16-bit modules provide one channel of memory, while 32-bit modules provide two channels. Therefore, a dual channel mainboard accepting 16-bit modules must have RIMMs added or removed in pairs. A dual channel mainboard accepting 32-bit modules can have single RIMMs added or removed as well. Note that some of the later 32 bit modules had 232 pins as compared to the older 184 pin 16 bit modules.[1]
Performance
Compared to other contemporary standards, Rambus shows a significant increase in latency, heat output, manufacturing complexity, and cost. Because of the way Rambus designed RDRAM, RDRAM's die size is inherently larger than similar SDRAM chips. RDRAM's die size is larger because it is required to house the added interface and results in a 10-20 percent price premium at 16-megabit densities and adds about a 5 percent penalty at 64M.[1]AM was no longer supported by any mainstream computing architecture.
[attachment=31013]
Direct Rambus DRAM or DRDRAM (sometimes just called Rambus DRAM or RDRAM) is a type of synchronous dynamic RAM. RDRAM was developed by Rambus inc., in the mid-1990s as a replacement for then-prevalent DIMM SDRAM memory architecture.
RDRAM was initially expected to become the standard in PC memory, especially after Intel agreed to license the Rambus technology for use with its future chipsets. Further, RDRAM was expected to become a standard for VRAM. However, RDRAM got embroiled in a standards war with an alternative technology - DDR SDRAM, quickly losing out on grounds of price, and, later on, performance. By the early 2000s, RDRPC main memory
The first PC motherboards with support for RDRAM debuted in late 1999, after two major delays. RDRAM was controversial during its widespread use by Intel for having high licensing fees, high cost, being a proprietary standard, and low performance advantages for the increased cost. RDRAM and DDR SDRAM were involved in a standards war. PC-800 RDRAM, which operated at 400 MHz and delivered 1600 MB/s of bandwidth over a 16-bit bus. It was packaged as a 184-pin RIMM (Rambus in-line memory module) form factor, similar to a DIMM (dual in-line memory module). Data is transferred on both the rising and falling edges of the clock signal, a technique known as DDR. For marketing reasons the physical clock rate was multiplied by two (because of the DDR operation); therefore, the 400 MHz Rambus standard was named PC-800. This was significantly faster than the previous standard, PC-133 SDRAM, which operated at 133 MHz and delivered 1066 MB/s of bandwidth over a 64-bit bus using a 168-pin DIMM form factor.
RDRAM memory with integrated heat spreader
Moreover, if a mainboard has a dual- or quad-channel memory subsystem, all of the memory channels must be upgraded simultaneously. 16-bit modules provide one channel of memory, while 32-bit modules provide two channels. Therefore, a dual channel mainboard accepting 16-bit modules must have RIMMs added or removed in pairs. A dual channel mainboard accepting 32-bit modules can have single RIMMs added or removed as well. Note that some of the later 32 bit modules had 232 pins as compared to the older 184 pin 16 bit modules.[1]
Performance
Compared to other contemporary standards, Rambus shows a significant increase in latency, heat output, manufacturing complexity, and cost. Because of the way Rambus designed RDRAM, RDRAM's die size is inherently larger than similar SDRAM chips. RDRAM's die size is larger because it is required to house the added interface and results in a 10-20 percent price premium at 16-megabit densities and adds about a 5 percent penalty at 64M.[1]AM was no longer supported by any mainstream computing architecture.