MWNY DDR RAM? Actual G4 does NOT support DDRam!!!

[Shaktai]

New G4chips will be 7460/7470. They support 133 & 166 FSB with DD Ram for effective throughput of 266 or 333. Don't know which we will see though. At least the 266. This combined with a larger 512k L2 cache running at processor speed and the usual L3 cache at half speed, will provide substantial performance boosts in excess of just the CPU speed jumps. The new mobo's though may not support "booting" into Mac OS-9, though OS-9 will still run "within" OS-X. If you need to run OS-9, get plenty of RAM (512 mb minimum) and it should run just fine under 10.2. Just won't be able to boot into it.

Combination of Processor speed bump, DD Ram and Jaguar should provide an effective overall speed boost of almost 60%.

 

[kansaigaijin]

G4 don't support DDR?

from Apple's Xserve page,

133MHz system bus supporting over 1GB/s data throughput

Memory
256MB or 512MB of 266MHz PC2100 DDR SDRAM with up to 2.1GB/s throughput

 

[AlphaTech]

Never mind the fact that the L3 cache memory IS DDR...

The motherboard design has a lot to do with the memory type. The Xserve has proven in that the current G4 chips can [easily] use DDR memory.

From the peecee standpoint, I have seen more then a few motherboards made for the Athlon (Duron, T-Bird, not 100% on the xp chip) that use PC100/133 memory. Others use DDR (PC1600, 2100, 2700) memory. While the number of boards that use the PC100/133 memory is shrinking, there are still plenty of them out there.

Same with intel chips. We have more then a few IBM boxes, using the p4, that use PC133 memory.

To say that either AMD's or intel's latest chips cannot use DDR memory because of these other boards is about as stupid/moronic as saying that the current line of G4 chips cannot use/do not support DDR memory.

 

[dekator]

Xserve vs Dual 1Ghz

The Switzerland based company BITcom has done some benchmark testing with the Xserver and found that the 1GHz set up is very closely just as fast as a current Dual Ghz G4 in two tests and faster in a third.
This seems to be due to the DDR RAM and the hard disc I/O system used in the Xserve.
The test is available as a QT movie on MacTV .
Note that this is a german-language site. You shouldn't have a problem to find the article that has "Xserve-Test" in its headline. Just click the metallic button that reads "Film starten" (guess what that means ;-) and watch the film.
The commentary in the movie is in German too, but results are displayed in a way that is self-explicatory and understandable for everyone.

 

[Chryx]

Originally posted by AlphaTech
To say that either AMD's or intel's latest chips cannot use DDR memory because of these other boards is about as stupid/moronic as saying that the current line of G4 chips cannot use/do not support DDR memory.

It's a bit more complex than that,

a processor can be "used with" a memory type but not be able to "use" that memory type (to it's full advantage)

the northbridge <> processor link and the northbridge <> memory link are seperate, one can be DDR whilst the other is not, they can even be clocked differently.

and in a lot of cases, adding a faster memory bus can make _zero_ difference because the processor itself can't make any use of the extra bandwidth, for example AthlonXP's paired up with PC2700 memory, you get 600MB/s of memory bandwidth that is useless as far as the processor is concerned.

In much the same way, a G4 (or a Pentium 3) with a 133Mhz Single Data Rate link between itself and the northbridge, won't be able to take full advantage of PC2100 (although it's arguable that they would get closer to bus saturation more often)

I don't know what Apple did with their new northbridge/memory controller, but it's not _just_ the extra memory bandwidth making the difference. (I'm wondering if they put an Sram cache on the die to lower effective memory latency or something?)