PC150 RAM in a G4?

Posted by: apsinnott

PC150 RAM in a G4? - 12/09/01 09:57 AM

Hello fellow Mac fans,<br><br> I was searching for various upgrades and add-ons for the PowerMac G4 I plan to buy when I came across SDRAM DIMMs rated at 150 MHz versus the standard PC133.<br><br> It is my understanding that this rating simply indicates how fast the RAM Chip is capable of operating (in warm and fuzzy terms). That specification, combined with the CAS latency and Ms (Millisecond) rating equals the total speed of the RAM chip.<br><br> It is also my understanding that being exactly the same SDRAM DIMM chip, except rated to higher MHz, means you can use PC150 in a PC133 slot.<br><br> With the great expense of a new PowerMac G4 system at hand, I have been looking to make it the best system possible, in order to extend its usable life. I plan to purchase it with Ultra160 SCSI HDs (rated @ 10,000 RPM!), dual processors, GeForce3, etc. Of course, I want the fastest RAM as possible as well. Apple doesn't seem to tell you what type of RAM is in the G4 at default (specifications of the chips) and their ridiculous RAM prices have made me consider after market RAM. Since the RAM in the G4 is a standard SDRAM finding cheap and fast PC133 chips is easy. I had my eyes set on three PC133 512MB CAS latency of 2 and a <7 MS rating.<br><br> Then I found the PC150 RAM. Exactly the same specification (512MB/2CAS/6.5MS) except rated to 150 MHz. So, what I am asking is whether anyone has tried these chips, any ideas on whether or not they will work at all, etc. I also plan to purchase a RAM cooler, to "strap-on" the chips to keep them as cool as possible to avoid heat problems inherent to high speed processing. Technically, they should just plug in and work faster then PC133, but who knows.<br><br> I could, of course, just wait till Apple puts DDR SDRAM in the G4s, but then I would have the same question except with high rated DDR chips :)<br><br> Any info, tips, etc, would be most appreciated.<br><br> Cheers,<br><br> Adrian<br><br>
Posted by: Anonymous

Re: PC150 RAM in a G4? - 12/09/01 01:04 PM

Higher MHz Dimms have invariably worked in Macs. I have [not] tried PC150 in a PC100 or PC133 Mac, however.<br><br>I loaded up with PC133 Dimms for my 100MHz bus in present G4 DP (gigabye). No problem. And a lot of others of done the same with the anticipation that the PC133 Dimms would work in future models.<br><br>Right now, unless I had to have it I would invest a dime in memory of any kind for any Mac. It all depends on which rumor you want to believe. It's possible that PC150 dimms will be in any new G4. It's possible the new ones will take DDR chips.<br><br>No one except Apple and its top 3rd party vendors like Adobe or Microsoft know presently. I'd defnitely wait until Mac expo.<br><br>Sorry, can't definitely answer your question about PC150 in a 133 or 100 G4 Mac. But also keep in mind that Dimms have to be made to meet specific Apple standards which are not necessarily the industry standard. One "feature" of Apple's standards wound up creating major havoc this year when a firmware upgrade "found" some third party memory that wasn't up to spec. Many folks found this out the hard way and struggled with minimal memory for a few weeks until a third party (and many memory vendors) "solved" it.<br><br>I'd therefore only consider buying it if the vendor would guarantee it was in compliance with Apple standards, full return or exchange, etc. etc. You're unlikely to find this with very many vendors. The fact that someone here or on MacFixIt or anywhere else says they have found it works doesn't mean it will for you.<br><br>I'd also not consider buying it if the vendor sells only to the *86 market and doesn't know anything about Macs. This is one area where RamJet, ChipMerchant, and some of the folks that are heavy hitters in the Mac market become the best vendor. Saving five bucks on a Dimm from a nobody or smaller Mac vendor is stupid IMHO. I personally buy memory only from RamJet or OWC because they're in the Mac memory business (and also PC), do high volume, and know what they're doing. Been there and done that. I've personally made 2 or 3 dozen purchases of memory in the last 2 years for the "family" of Macs and PCs I support. In my business the purchases are in the hundreds and I notice my IS people deal almost exclusively with RamJet with some business going to Chip Merchant. They not be the cheapest, but sooner or later you find out the hard way why you should of spent 5 or 10 bucks more. Been there and done that. <br><br>Even if you buy from that same vendor he may have change suppliers, as they all do, and the Dimms that are presently intended for use in the x86 world aren't going to work with a Mac.<br><br>Memory is presently just too cheap to consider thinking of saving ten bucks by getting PC150 because you find a good deal on a 133 or 100 Mac pre-MacWorld Expo.<br><br>And quite frankly I'd have to find an awfully good deal to buy a pre-MacWorld Expo G4 of any kind right now. The TiBook G4 500, for example, is sinking in price and should take a dive after Christmas before Expo. Same for the TiBook 400 and any G4 Tower 350 and up.<br><br>Long way around.......sorry. <br><br>But I certainly wouldn't take the word of five or six people, if you can find them, who say PC 150 2-2-2 SDRAM will work in a 133 or 100 G4 Mac. Also keep in mind that a lot of dimms out there, especially PC 150, were specifically manufactured for *86 CPUs. In some cases they won't seem come close to working in a Mac as the "polarity" (wrong term, can't think of it) is opposite of what Mac uses.<br><br>The poorest bargains in buying Mac hardware and software are in memory IMHO. MacWorld Expo is one month away. <br><br>(Sorry if some folks don't like "wait" messages because they think it hurts Apple. Sorry, it goes with the territory. Great deal pre-Expo and the Mac is what you need? Fine. Buy it. It had better be a great deal.) <br><br>Pontification ends.<br><br><br>128k_Mac<br><br>"The box said 'Requires Windows XP or better' so I bought a Macintosh." - Anonymous