Memory Designations

profdlpprofdlp The Holy City Of Westlake, Ohio
edited June 2003 in Hardware
Just about the time I was feeling comfortable with the move from the old-old naming convention for memory (i.e. FP, EDO) to the more logical PC-66, PC-100, etc style, the companies moved to the PC2100, etc format.

Forgive me if I'm wrong, but isn't there a direct correlation between the old naming convention and the new(est) one?
(i.e. PC2100 = PC-266, or whatever)

If I'm right about that, does anyone know of a chart showing the correlation between the two for all modern (DDR) memory chips?

If I'm wrong, could someone straighten me out?

And wasn't life easier when you just looked for a memory configuration equal to your FSB? Why was this changed?


Prof
(I must be getting old...)

Comments

  • ClutchClutch North Carolina New
    edited June 2003
    184 pin DDR DIMM

    pc2100 133mhz
    pc2400 150mhz
    pc2700 166mhz
    pc3000 188mhz
    pc3200 200mhz
    pc3500 216mhz
  • edited June 2003
    The only one Clutch didn't include:

    PC1600 100 Mhz

    :nudge::D
  • ClutchClutch North Carolina New
    edited June 2003
    muddocktor said
    The only one Clutch didn't include:

    PC1600 100 Mhz

    :nudge::D

    :banghead: :banghead: good call Mudd
  • profdlpprofdlp The Holy City Of Westlake, Ohio
    edited June 2003
    Thanks for the info. This is being cut-and-pasted into a document for reference purposes.

    As to part II - Why did they change the name? Just to confuse people? Or is it the "more is better" philosophy, where bigger numbers seem more impressive?


    Prof
  • ThraxThrax 🐌 Austin, TX Icrontian
    edited June 2003
    <p><strong>DDR-SDRAM:</strong><br> “Double Data Rate Synchronous Dynamic Random Access Memory.”</p><p>The unique property of DDR-SDRAM allows it to calculate twice on each oscillation of the clock, both at the top of the wavelength, then once more at the bottom.</p>
    <p>What is commonly called DDR-RAM has two different naming nomenclatures.<br> The first naming scheme rates the modules in terms of maximum possible bandwidth in megabytes per second. The various types when described in this way is as follows:</p>
    <p> </p><table width="28%" border="0" align="center"><tr bgcolor="#666666"><td><div align="center"><strong>Memory Type</strong></div></td><td><div align="center"><strong>JEDEC Ratified?</strong></div></td><td><div align="center"><strong>Frontside Bus Speed</strong></div></td><td><strong>Bandwidth</strong></td></tr><tr bgcolor="#999999"> <td>PC1600</td><td>Yes</td><td>100MHz</td><td>1600MB/s</td></tr><tr bgcolor="#999999"><td>PC2100</td><td>Yes</td><td>133MHz</td><td>2100MB/s</td></tr><tr bgcolor="#999999"><td>PC2400</td><td>No</td><td>150MHz</td><td>2400MB/s</td></tr><tr bgcolor="#999999"><td>PC2700</td><td>Yes</td><td>166MHz</td><td>2700MB/s</td></tr><tr bgcolor="#999999"><td>PC3000</td><td>No</td><td>187MHz</td><td>3000MB/s</td></tr><tr bgcolor="#999999"><td>PC3200</td><td>Yes</td><td>200MHz</td><td>3200MB/s</td></tr><tr bgcolor="#999999"><td>PC3500</td><td>No</td><td>219MHz</td><td>3500MB/s</td></tr><tr bgcolor="#999999"><td>PC3700</td><td>No</td><td>231MHz</td><td>3700MB/s</td></tr></table><p>The second naming scheme rates the modules in terms of the frontside bus (FSB) they run on multiplied by two. This being the case, here are the same memory types as above listed in the new scheme, and in the same order:</p><table width="28%" border="0" align="center"><tr bgcolor="#666666"> <td><div align="center"><strong>Memory Type</strong></div></td><td><div align="center"><strong>JEDEC Ratified?</strong></div></td><td><div align="center"><strong>Frontside Bus Speed</strong></div></td><td><strong>Bandwidth</strong></td></tr><tr bgcolor="#999999"><td>DDR200</td><td>Yes</td><td>100MHz</td><td>1600MB/s</td></tr><tr bgcolor="#999999"><td>DDR266</td><td>Yes</td><td>133MHz</td><td>2100MB/s</td></tr><tr bgcolor="#999999"> <td>DDR300</td><td>No</td><td>150MHz</td><td>2400MB/s</td></tr><tr bgcolor="#999999"><td>DDR333</td><td>Yes</td><td>166MHz</td><td>2700MB/s</td></tr><tr bgcolor="#999999"><td>DDR374</td><td>No</td><td>187MHz</td><td>3000MB/s</td></tr><tr bgcolor="#999999"><td>DDR400</td><td>Yes</td><td>200MHz</td><td>3200MB/s</td></tr><tr bgcolor="#999999"><td>DDR433</td><td>No</td><td>219MHz</td><td>3500MB/s</td></tr><tr bgcolor="#999999"><td>DDR466</td><td>No</td><td>231MHz</td><td>3700MB/s</td></tr></table>
    <p> </p><p>To get the name of the official RAM type you take the clock cycles per second and multiply by 8 (The 8 stands for 8 bytes, or the width of the system bus currently employed on Intel/AMD systems 8 bytes is 64 bits). The processor is capable of addressing 64 bits, even though the processor is only 32 bits.</p><p>The equation example would be as follows:</p><p>FSB * 2 * 8 = x</p><p>To calculate PC2100:</p><p>133 * 2 * 8 = 2128 MB/s<br></p>

    DRAM and You; A Guide to Memory Technologies
    Version 2.0; Robert "Thrax" Hallock
  • SpinnerSpinner Birmingham, UK
    edited June 2003
    I imagine though that on a basic level it was also to distinguish DDR memory from basic SDRAM. As having two different types of memory (based on a modules core frequency) called PC100 and PC133 would get confusing. Not that some of you don't seem to be confused still.;)
  • profdlpprofdlp The Holy City Of Westlake, Ohio
    edited June 2003
    That's the kind of lay-it-all-out plain English answer I have been seeking for years. I have searched high and low, but haven't found anything nearly as informative.

    Thanks A Bunch!:p


    Prof
  • ClutchClutch North Carolina New
    edited June 2003
    I know what you mean profdlp, I hate it when you see an article trying to explain something, but in the end your still like "wtf?" I love simple, but very effective answers. Great info also Thrax :)
  • mmonninmmonnin Centreville, VA
    edited June 2003
    Where is version 2 of that memory thread of yours Thrax??
  • ThraxThrax 🐌 Austin, TX Icrontian
    edited June 2003
    MIA.
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