"Crippled" DDR on new G5's?

Faster memory is always coming out; it's a fact of life, just like faster processors come out as well.

 

*YAWN!*

complain complain complain.

go do something constructive.

 

exactly! Shut up already.

Article was probably written by a closet PC user who is pissed that they still use windows.

 

Well, this part is completely false:

and this part:

is referring to Rambus which will hardly be a widely used replacement for Dual-Channel DDR (IMHO). It certainly won't be an inexpensive option.

Based on the application tests shown at WWDC, I think the performance of these systems will be more than enough for just about anyone's needs.

 

First of all, are 1.0 releases ever completely safe?

How many cars, computers, etc. work without a glitch first time out?

As far as I know, the G5 machines are not perfect but they're impressive. Are they going to reach their full potential right away? No! They're being released with an operating system working in a hybrid 32-64-bit mode.

As far as DDR RAM goes, saying that there's a new standard and populating motherboards with actual specimens are two different things. It was surprising to me that Apple chose RAM that was already available instead of helping develop some innovative packaging which contained much faster memory. Then again, in the initial PowerMacs, they used 72 pin SIMMs in pairs. With the PCI PowerMacs, they used DIMMs, ahead of the rest of the industry.

Newer machines will be faster and better--that's the way of things.

 

The only thing faster then DDR400 will be DDR-II which will not be a standard for probably another year. It might make it into high end machines come the first of the year but it is still very pricey.

 

That article is probably written by same person who complained about unfairness of early test comparison between G5 and Pentium PC's.

 

I am confused because if you take just about any high end performance PC, they use DDR 400 RAM, too...so if they accuse Apple of using "out of date" tech, then accuse Dell and Gateway and Toshiba and Sony and etc, too...we just got a brand new top of the line Dell system for the family computer and guess what? It uses DDR 400 RAM, too...I don't see them bashing Dell for using DDR 400.

 

I bet it doesn't used paired DDR 400. Meaning it still runs at half the speed of the memory architecture of that in the G5.

 

Rambus will never become a major player (Heck Intel doesn't even make boards that accept RIMMS anymore, and were the only ones who ever did (In great Quanity)), because they have quirks, act like simms and cost as much as the "Star Wars" Defense Project.

I would like to See DDR-II, but we all know that it may be a while before we'll have them.

With sentiments like that guy's, I know now why the Cube failed.

TEG

 

The most inaccurate part is this:

"Also, a point no one seems to has mentioned. Altivec has been updated, meaning all apps that took advantage of the Altivec processor need to be updated (re-coded) to take advantage of the G5s speed."

I suggest that no-one has mentioned it because it is completely false. The Altivec unit is slightly different, but use the same instructions, I believe.

Apps have to be re-compiled for the G5 to see the biggest speed gains, but that is true of most new processor designs- and I don't think this is because of Altivec being a slightly different in the G5 (more like the older G4's, I believe). It won't be like the jump to PowerPC, where many apps were much slower on a 6100 than they were on a Quadra 840 or 950.

 

When the computer was announced, people looked around and found that there really were not that many large sticks of memory to be had.

It even seemed that Apple was offering memory configurations that the market couldn't supply, yet.

It's a little hard to say that Apple is using a dead standard, when it's hard to buy 1-2 GB sticks of memory for the darn machines at DDR400.

Like, how would you expect to add DDR2 memory to the machine if Apple offered it?

With a home mortgage?

 

Actually, some Altivec commands are extremely slow (slower than it would be without the Altivec) and others don't work at all. So yes, some apps do need to be recompiled due to the change.

 

Not that big of a shift, true. But still... why do you think Adobe was there for the intro? The get to sell new "G5 optimized" stuff, offer minor bug fixes and new feature or two, and watch the faithful upgrade their 1 yr old software!

*sigh*

What can you do?

 

The PPC970's vector pipelines include all 162 instructions in the AltiVec specification. That said, the vector processor is poorly integrated into the unit. It seems that it was really just sort of shoehorned in there (remember, there is no vector processor in the Power4). As a result, the current version of the 970 is not any better than the G4e at vector processing, and it is even worse at some instructions.

 

Not make a purchase?

 

Oh come on, we have the fastest bus on the planet now. 1 Ghz! Dual independent buses at that meaning data doesn't get crammed waiting to go in while other data goes out! Apple developer specs say with 2 GB PC-3200 modules (about $1100 through Pricewatch.com) you can get 16 GB of RAM into the machines. The system runs so much cooler because of the great design of the locations of the fans. Cooler means faster. To top it off, no longer are we limited to ATA/133 ATA, we have Serial ATA at 1.5 GB a second on the hard disk. The biggest slowdown on any machine is the hard disk, not the chips. The 1.6 Ghz G5, nice entry level machine, but not the one I'd get. I'd either get the 1.8 Ghz or the 2 Ghz. The 1.6 doesn't even have PCI-X. This coming off Macs that had buses at a maximum of 167 Mhz while all the people on this board were whaling that the bus made a huge difference. You got your faster bus, you got your faster hard drive, you got your memory capacity, you got your faster PCI slots, you got your faster AGP slot. You even got your digital audio ports. The way people carry on in here, they are expecting the M-5 from Star Trek to actually have been made 30 years ago and available in the desktop today. PCers are just jealous. We have the most secure system on the planet, and now the fastest for under $3000 with built-in developer tools. The tests were run at 32 bit. Imagine what it will be like at 64 bit. Oh and did you notice, the Opteron has to be rebooted to switch from 64 bit to 32 bit applications. The G5 does not. Imagine the time savings there!

 

I personally cannot wait for the G5s to make it into maturity across Apple's different product lines.

 

Yeah whoever wrote that article is out of touch. But anyway, since everyone already knew that...

MacBandit:

Dual channel DDR isn't unusual in PC land, and in fact dual Opterons can support 4 channels of DDR (although current dual Opteron boards only have 2 channels). Tyan has such a board coming, but all those DIMM slots (16) make it huge and, I bet, expensive.

TEG:

Rambus lost their first battle for the desktop, but the war isn't over yet.

crazzyeddie:

I think they all work, just some memory commands require that the pipeline be flushed, as far as I know.

gopher:

A processor at a given clockspeed is exactly the same "fast-ness" at every temperature that it can run at without error.

No, it does not. At this link you can see AMD making repeated claims about "simultaneous 32- and 64-bit computing".

http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_8826_8832,00.html

 

Most of the article is crap but he does have a point about the memory, the G5's 1 GHz bus (8 GB/s peak) is going to be "bottlenecked" by Dual Channel DDR-400 (6.4 GB/s peak). Not that it matters much as the G5 is fast enough already. It's just that it (the G5) will become significantly faster when Apple implements PC4000 DDR-500 (which is out by the way) or Quad Channel RDRAM. Remember, more speed is always a good thing.

 

This is still a brand new system...give it time to mature and we'll all be amazed with the capabilities, I am sure.

 

How does a processor without an altivec execute an altivec instruction?

I've never heard anything to that end: link?

Lots of the "970 is crap at altivec" comments are from people who have heard comments from people who read the first two Ars Technica 970 articles. There were mistakes in their discription of the unit, which are corrected here:
http://www.arstechnica.com/cpu/03q2/ppc970-interview/ppc970-interview-2.html

But the original article was just criticising how the unit managed dispatches- not that it couldn't handle some of the altivec instruction set. If it wasn't compatible with the existing instructions from the G4, then it would be pretty useless to Apple. The 970 was designed by Apple and IBM together. I think Altivec compatibility was a major target for them.

The recompiles are for optimisation for the new (to the Mac) architecture of the rest of the chip that evolved from the POWER4- not for the only part of the 970 which came from the Mac's existing processors.

 

Not sure that this is a pertinent, but... I sometimes use my parents' Pentium4 which is 1.4 ghz. It has the aforementioned rambus memory, and is ridiculously slow. I had to order the RIMM from the internet b/c nobody in town sells it. It is complete garbage. Thankfully, I have my 400 mhz imac right next to it on the same desk. I am so much more productive thanks to Apple and OSX. I can't wait till my G5 ships so I can see just how pitiful the pentium really is.

 

Don't believe everything you hear.

A lot of what you just said is completely false.
Rambus sucks, altivec hasn't changed in the G5 (it's only gotten more room to work with it now), etc etc