What´s the difference between DDR and SDRAM?

Posted:
in Current Mac Hardware edited January 2014
In video editing, is it faster the DDR than the SDR?

And I wanna know also the diference betwen the NVIDIA GeForce 4-420 and the ATI Mobilty Radeon 9000 (or 7500)

How do I change the monitor on my PBti15" to an external monitor?

Comments

  • Reply 1 of 9
    stoostoo Posts: 1,490member
    SDRAM is Synchronous Dynamic Random Access memory: synchronous means that the flow of data to and from the RAM is governed by a clock. For SDRAM the clock is between 66MHz (first generation G3s, first iMac) to 133MHz (today's G4s). Currently, SDRAM, like the G4's bus, transfers 64bits per transaction.



    However, there are 2 kinds of SDRAM: the old kind, single data rate (SDR), and the new kind, double data rate (DDR). The difference is that SDR SDRAM transfers data once per clock cycle, but DDR SDRAM transfers data twice per clock cycle, on the rising and falling edges of the clock pulse, making it about twice as fast as SDR for the same clock rate.



    However, the situation is confused by the G4's bus. Currently , the G4 (or pair of G4s, as dual G4s share one bus) has a 166MHz single data rate bus, which has less bandwidth than the 133MHz DDR SDRAM (effectively 266MHz). Fortunately, devices like video cards, hard drives, etc.. have been able to access memory directly without going through the CPU for a while now, so fast memory isn't wasted on a PowerMac.



    To connect and external monitor to a 15" PowerBook: are you intending to connect a flat panel or a CRT monitor?
  • Reply 2 of 9
    isemirisemir Posts: 11member
    Thank you !! But, what about the video card? Does the 9000 ATI Radeon is better? For what I have heard there has been a little problems with the NVIDIA cards...
  • Reply 3 of 9
    newnew Posts: 3,244member
    Quote:

    Originally posted by isemir

    In video editing, is it faster the DDR than the SDR?

    And I wanna know also the diference betwen the NVIDIA GeForce 4-420 and the ATI Mobilty Radeon 9000 (or 7500)

    How do I change the monitor on my PBti15" to an external monitor?




    So you ended up buying the TiBook? :-)

    It will pretty much discover any monitor itself.
  • Reply 4 of 9
    isemirisemir Posts: 11member
    Yes, I´d bougth it on the Apple Store, now I own a TiBook 15"
  • Reply 5 of 9
    newnew Posts: 3,244member
    Quote:

    Originally posted by isemir

    Yes, I´d bougth it on the Apple Store, now I own a TiBook 15"



    Concrats, forget about the Nvida cards. The radeon in the 15" is better.

    Did you get the monitor work?
  • Reply 6 of 9
    isemirisemir Posts: 11member
    Unfortunately no : (

    I was in a middle of a presentation of clinical cases and i have´nt tested the TiBook...

    So when i tried to conect it to the infocus...

    well it does´nt work

    So I have to use a pc (giakk !!) for my presentation
  • Reply 7 of 9
    newnew Posts: 3,244member
    Quote:

    Originally posted by isemir

    Unfortunately no : (

    I was in a middle of a presentation of clinical cases and i have´nt tested the TiBook...

    So when i tried to conect it to the infocus...

    well it does´nt work

    So I have to use a pc (giakk !!) for my presentation




    if it was a normal vga it should work easier than a PC, next time try closing the powerbook and opening it again. It should discover the projector immediately.
  • Reply 8 of 9
    isemirisemir Posts: 11member
    Ok...

    By the way...

    Have you ever used the Apple Keynote in presentations?

    We all here use the MS Power Point, an it is getting bored... Sometimes we use the powerplugs apps.

    The templates in PP are nice I´d think better than the Keynote´s. But the transitions in Keynote are definitely STUNNING !!!!
  • Reply 9 of 9
    newnew Posts: 3,244member
    Quote:

    Originally posted by isemir

    Ok...

    By the way...

    Have you ever used the Apple Keynote in presentations?

    We all here use the MS Power Point, an it is getting bored... Sometimes we use the powerplugs apps.

    The templates in PP are nice I´d think better than the Keynote´s. But the transitions in Keynote are definitely STUNNING !!!!




    keynote is really nice. The interface and ease of use will certainly turn some heads. 8)
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