3200mhz is the XMP speed (overclocked speed). In your bios you would enable the XMP profile to make the memory run at those overclocked speeds. There is no guarantee they will work tho. If they dont then entering the values manually in the bios sometimes help or entering values close to the XMP. JEDEC SDRAM not only has a synchronous interface controlled by the system clock, it also includes a dual-bank architecture and burst mode (1-bit, 2-bit, 4-bit, 8-bit and full page).
Memory speed is one of the most convoluted specifications around, and is often misrepresented. As far as memory is concerned, JEDEC lists the criteria that, say, DDR4 needs to adhere to—for. The base supported memory speed is 2133MHz. HP, generally, does not provide XMP settings in the BIOS. RAM's SPD reads: JEDEC #1 444.4 MHz 6.0 6 6 16 23 1.500 V.
The JEDEC memory standards are the specifications for semiconductor memory circuits and similar storage devices promulgated by the Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association, a semiconductor trade and engineering standardization organization.
JEDEC Standard 100B.01 specifies common terms, units, and other definitions in use in the semiconductor industry. JESC21-C specifies semiconductor memories from the 256 bit static RAM to DDR4 SDRAM modules.
JEDEC standardization goals[edit]
The Joint Electron Device Engineering Council characterizes its standardization efforts as follows:[1]
JEDEC standards and publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for use by those other than JEDEC members, whether the standard is to be used either domestically or internationally.
JEDEC Standard 100B.01[edit]
JEDEC Standard 100B.01 is entitled Terms, Definitions, and Letter Symbols for Microcomputers, Microprocessors, and Memory Integrated Circuits. The purpose of the standard is to promote the uniform use of symbols, abbreviations, terms, and definitions throughout the semiconductor industry.[1]
Units of information[edit]
The specification defines the two common units of information:[2]
- The bit (b) is the smallest unit of information in the binary numeration system and is represented by the digits 0 and 1.
- The byte (B) is a binary character string typically operated upon as one unit. It is usually shorter than a computer word.
Unit prefixes for semiconductor storage capacity[edit]
The specification contains definitions of the commonly used prefixes kilo, mega, and giga usually combined with the units byte and bit to designate multiples of the units.
The specification cites three prefixes as follows:
- kilo (K): A multiplier equal to 1024 (210).
- mega (M): A multiplier equal to 1,048,576 (220 or K2, where K = 1024).
- giga (G): A multiplier equal to 1,073,741,824 (230 or K3, where K = 1024).
The specification notes that these prefixes are included in the document only to reflect common usage. It refers to the IEEE/ASTM SI 10-1997 standard as stating, that 'this practice frequently leads to confusion and is deprecated'. However the JEDEC specification does not explicitly deprecate the common usage. The document further refers to the description of the IEC binary prefixes in Amendment 2 of IEC 60027-2, 'Letter symbols to be used in electrical technology', for an alternate system of prefixes[notes 1] and includes a table of the IEC prefixes in the note. However the JEDEC specification does not explicitly include the IEC prefixes in the list of general terms and definitions.
The document notes that these prefixes are used in their decimal sense for serial communication data rates measured in bits.
JESD21-C[edit]
The standard JESD21-C: Configurations for Solid State Memories is maintained by JEDEC committee JC41. This committee consists of members from manufacturers of microprocessors, memory ICs, memory modules, and other components, as well as component integrators, such as video card and personal computer makers. Standard 21 is published in loose-leaf binder format to accommodate frequent updates.
The documentation of modern memory modules, such as the standards for the memory ICs[3] and a reference design of the module[4] requires over one hundred pages. The standards specify the physical and electrical characteristics of the modules, and include the data for computer simulations of the memory module operating in a system.[5]
Jedec Ram Speed Tester
Memory modules of the DDR2-SDRAM type are available for laptop, desktop, and server computers in a wide selection of capacities and access speeds. The standards specify memory module label formats for end-user markets.[6] For example:
1GB 2Rx4 PC2-3200P-333-11-D2 is a 1 GB DDR2 Registered DIMM, with address/command parity function, using 2 ranks of x4 SDRAMs operational to PC2-3200 performance with CAS Latency = 3, tRCD = 3, tRP = 3, using JEDEC SPD revision 1.1, raw card reference design file D revision 2 used for the assembly.
Storage capacities[edit]
The JEDEC terms dictionary includes definitions for prefixes kibi (Ki), mebi (Mi), gibi (Gi) and tebi (Ti) as powers of 2, and kilo, mega, giga and tera as powers of 10.[7] For example,
- 240 tebi Ti tera + binary: (210)4 = 1,099,511,627,776 tera: (103)4
The JEDEC DDR3 SDRAM standard JESD-79-3d uses Mb and Gb to specify binary memory capacity:[8] 'The purpose of this Standard is to define the minimum set of requirements for JEDEC compliant 512 Mb through 8 Gb for x4, x8, and x16 DDR3 SDRAM devices.'
See also[edit]
Notes[edit]
- ^Quote from JEDEC Standard 100B.01, page 8:
The definitions of kilo, giga, and mega based on powers of two are included only to reflect common usage. IEEE/ASTM SI 10-1997 states 'This practice frequently leads to confusion and is deprecated.' Further confusion results from the popular use of the megabyte representing 1 024 000 bytes to define the capacity of the 1.44-MB high-density diskette. An alternative system is found in Amendment 2 to IEC 60027-2: Letter symbols to be used in electrical technology – Part 2.
Jedec Ram Speed Kit
References[edit]
- ^ abJEDEC Solid State Technology Association (December 2002). 'Terms, Definitions, and Letter Symbols for Microcomputers, Microprocessors, and Memory Integrated Circuits'(PDF). JESD 100B.01. p. 8. Retrieved 2009-04-05.
- ^Ref. ANSI X3.172.
- ^JEDEC, Double Data Rate (DDR) SDRAM Specification(PDF), archived from the original(pdf) on 2006-10-02, retrieved 2013-08-08
- ^JEDEC (2007), EP2-2100 DDR2 SDRAM 32b-SO-DIMM Reference Design Specification(PDF), retrieved 2009-04-05
- ^JEDEC, Bit Wide TTL SRAM(PDF), archived from the original(pdf) on 2003-04-20, retrieved 2013-08-08
- ^JEDEC, Preliminary publication of JEDEC Semiconductor Memory Standard(PDF), archived from the original(pdf) on 2007-09-26, retrieved 2013-08-08
- ^JEDEC dictionary entry
- ^http://www.jedec.org/standards-documents/docs/jesd-79-3d
External links[edit]
Jedec Ram Speed Definition
Frequency is the most advertised spec of RAM. As anyone who’s dug a little deeper knows, memory performance depends on timings as well--and not just the primary ones. We found this out the hard way while doing comparative testing for an article on extremely high frequency memory which refused to stabilize. We shelved that article indefinitely, but due to reader interest (thanks, John), we decided to explore memory subtimings in greater depth.
Jedec Ram Speed Test
This content hopes to define memory timings and demystify the primary timings, including CAS (CL), tRAS, tRP, tRAS, and tRCD. As we define primary memory timings, we’ll also demonstrate how some memory ratios work (and how they sometimes can operate out of ratio), and how much tertiary and secondary timings (like tRFC) can impact performance. Our goal is to revisit this topic with a secondary and tertiary timings deep-dive, similar to this one.
We got information and advice from several memory and motherboard manufacturers in the course of our research, and we were warned multiple times about the difficulty of tackling this subject. On the one hand, it’s easy to get lost in minutiae, and on the other it’s easy to summarize things incorrectly. As ASUS told us, “you need to take your time on this one.” This is a general introduction, to be followed by another article with more detail on secondary and tertiary timings.