Buying A G4: Ddr Sdram Vs. Quicksilver?, Performance issues in design of new G4sb Options

Here's the situation: Me: bright young computer musician just beginning a career in digital signal processing. Apple: company, which, up until now, made relatively nice computers for creative applications. The Quandry: Apple releases a new round of G4s, equipped with newer ddr sdram. However I have seen much information indicating these new computers are NOT as capable of handling the type of real-time processing I would like to do as the previous quicksilver G4s which used non-ddr sdram. The crux lies in the design: the new machines have a 1mb/proc L3 cache, while the older machines have a 2mb/proc cache. Also Moto's system bus doesnt have the bandwidth to make use of the DDR sdram properly, and may cause more bottleneck problems than it was introduced to solve.
(benchmark info and ddr sdram kludge?).

Does anyone here think the ddr sdram G4s will pose any restraints to heavy real-time number crunching for sound-synthesis and dsp stuff? This is only an issue because Apple has completely pulled the line of older quicksilver G4s and my chances of getting one are rapidly scaling to zero. I emailed a guy at Apple, who does music, about this, but am still waiting for his reply. Thanks for any suggestions the mac music community can provide me.


M.

Hi hmurchison
your post on the DDR implementation in the New Macs is most enlightening.

I do have a question about this implementation.

How do you think this will affect Audio systems like Pro Tools HD, Logic Audio Etc.

THe reason I ask is that I am planning on switching out the current G4 for one of these new Macs in the hope that I will get better performance off the Plug Ins that use CPU resources heavily such as Reaktor. I was also wondering if the Increased bus Speed and the DDR would cause any timing problems with TDM based systems.

So far DIGI has no comments

Stuartpa-

I think the DDR will help not in single app Benchmarks but in running heavy stuff like TDM in Protools. The thing you're looking for is relieving Bus Contention by having as many devices use DMA to grab their data directly from Main Memory. In that aspect the DDR is going to be a good solution. I think with ProTools 6 rumored to be coming that we should see some efficiency. Over at Digi User Conf I noted that a few Digi Techs said their eager to get an OSX version out and OSX capable DAE should be forthcoming.

I don't forsee any timing issues since the Bus changes haven't been too radical. I do know that AES this year is going to have some nifty stuff...just wish I could afford even a smidgen.

I subscribe to the Core Audio mailing list and the Developers are very positive about Core Audio. The few issues that are cropping are are fairly minor and Apple has documented well here. Digi should be up to speed very quickly.