On Dec 12, 2008, at 1:37 AM, Paul wrote:
> The G3 B/W tower and several early G4 towers all use PC100 memory, but > Other World Computing distinguishes between G3 and Yikes on one hand, > and AGP and Gigabit on the other. They don't recommend using the same > RAM in all of these, and told me that the programming and design of > the memory cards are different. > > Is this something I can "adjust" with DIMM First Aid? G3 B&W and early G4 models require at least PC100, but accepts many PC133. These models accept only "low density" sticks with a maximum capacity of 256 MB per stick. Four sticks, maximum, for a total capacity of 1 GB, maximum. Mid G4 models requires at least PC100, but accepts most PC133. These models accept only "low density" sticks with a maximum capacity of 512 MB per stick. Four sticks, maximum, for a total capacity of 2 GB, maximum. Late G4 models (to, and including the QS 2002) requires PC133, and accepts most PC133. These models also accept only "low density" sticks with a maximum capacity of 512 MB per stick. Three sticks, maximum, for a total capacity of 1.5 GB, maximum. DIMM First Aid may be able to adjust certain values within the SPD EEPROM, however this would generally be limited to changing a designation of higher performance to one of lower performance. As has been pointed out before, Apple's DRAM controllers implemented only selected portions of the JEDEC standards for SDRAM sticks. Those features which Apple elected not to implement, such as "high density" support, may lead to sticks being read as one-half of the stick's true capacity. Similarly, it is possible for a stick which was programmed to support multiple specifications (example: both PC100 and PC133) to be misread, and to be read as the wrong specification. Or, the right specification, just not the one the user expected. This, depending upon the boot ROM's version, or the version of MacOS itself. (This is why upgrading the boot ROM can affect which sticks are accepted, or are rejected, and results in much aggravation, when updating the boot ROM). Most vendors who have encountered problems with Apple customers have amended their sales literature to more specifically identify their products, so that these misunderstandings can be avoided. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
