Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Notebooks > 17" Apple Store oddity

17" Apple Store oddity
Thread Tools
all2ofme
Grizzled Veteran
Join Date: Mar 2001
Location: London, UK
Status: Offline
Reply With Quote
Jul 18, 2003, 06:47 AM
 
Does anyone know if the Apple Store has always displayed the incorrect RAM details for the 17" machine?

It states that it comes with 512MB of DDR333 SDRAM (instead of DDR PC2700). I don't imagine that this is a hint of something to come and it's been posted at the wrong time (as nothing else seems amiss), but it is a bit odd. Is it 333MHz RAM or something?
     
Link
Professional Poster
Join Date: Jun 2003
Location: Hyrule
Status: Offline
Reply With Quote
Jul 18, 2003, 07:51 AM
 
DDR 333 is another way of saying PC2700.

They are two different scales that are related. Long story...

333 = the clock speed overall, 167 is the actual speed it talks to the computer but it sends and recieves info twice in one clock cycle, thus the name DDR.

PC2700 has something to do with the .. well.. I have no freaking idea WHAT that means anymore.
Aloha
     
all2ofme  (op)
Grizzled Veteran
Join Date: Mar 2001
Location: London, UK
Status: Offline
Reply With Quote
Jul 18, 2003, 12:40 PM
 
Ah, ok. I wonder why Apple themselves name them inconsistently. On the Apple Store page they call it 333MHz RAM, on the tech specs page they call it PC2700.

Thanks for the info

Originally posted by Link:
DDR 333 is another way of saying PC2700.

They are two different scales that are related. Long story...

333 = the clock speed overall, 167 is the actual speed it talks to the computer but it sends and recieves info twice in one clock cycle, thus the name DDR.

PC2700 has something to do with the .. well.. I have no freaking idea WHAT that means anymore.
     
ibook_steve
Moderator
Join Date: Oct 2001
Location: San Jose, CA
Status: Offline
Reply With Quote
Jul 18, 2003, 01:32 PM
 
PC2100 and PC2700 refer to the data transfer rate on the memory bus. PC2100 (in the 12" Powerbook) means 2.1 GB/sec on the bus, which is running at 133 MHz, but transfers twice each clock cycle so it's like running at 266 MHz. PC2700 transfers 2.7 GB/sec with the 167 MHz clock doubled to 333 MHz. These are theoretical transfer rates, and they don't always happen this fast, but it's how the memory is specified.

Steve
     
iohead
Registered User
Join Date: Jan 2003
Location: California
Status: Offline
Reply With Quote
Jul 18, 2003, 01:36 PM
 
Originally posted by all2ofme:
Ah, ok. I wonder why Apple themselves name them inconsistently. On the Apple Store page they call it 333MHz RAM, on the tech specs page they call it PC2700.

Thanks for the info
The bus speed in question here is 167 MHz. DDR (double-data-rate) effectively runs at twice that speed: approximately 333 MHz. PC2700 refers to the data bandwidth of the RAM:

333 MHz * 64 bit / (8 bits / byte)
= 2672 Mbytes/s
~= 2700 MB/s

Hence, PC2700 ~= 333 MHz DDR etc.

Regards
     
   
Thread Tools
 
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Top
Privacy Policy
All times are GMT -4. The time now is 09:48 PM.
All contents of these forums © 1995-2017 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2017, Jelsoft Enterprises Ltd.,