Generally yes, there are a couple of oddballs
JEDEC Specifications and Naming Convention
The specifications for DDR memory modules are developed and approved by JEDEC. JEDEC is the semiconductor standardization body of the Electronic Industries Alliance (EIA). About 300 member companies representing every segment of the industry actively participate to develop standards to meet the industry needs. Kingston is a long-time member of JEDEC and is active on the JEDEC Board of Directors as well as a number of memory technology committees.
JEDEC has completed specifications for PC1600 and PC2100, which are now widely available. Development work on faster DDR memory products is on-going.
JEDEC 200/266MHz DDR Specifications Summary
184 pin DIMM, ECC or non-ECC
200 pin SO-DIMM, ECC or non-ECC
172 pin Micro-DIMM, non-ECC
2.5 Volts
SSTL-2 I/O Interface
CAS Latencies: 2, 2.5
Serial Presence Detect (SPD) Support
Support for Memory Chip Stacking
DDR naming convention recommended by JEDEC:
Memory chips are referred to by their native speed:
For example, 200 MHz DDR SDRAM memory chips are called DDR200 chips, and 266 MHz DDR SDRAM memory chips are called DDR266 chips.
DDR modules are named after their peak bandwidth, which is the maximum amount of data that can be delivered per second:
A 200 MHz DDR DIMM is called a PC1600 DIMM, and a 266 MHz DDR DIMM is called a PC2100 DIMM.
See the DDR Memory Bandwidth section for details on how bandwidth is computed.