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G5 - thoughts?

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June 23, 2003 8:47:32 PM

Mac is marketing this as the "world's fastest personal computer." dual 2 gig 64 bit procesors with up to 8gigs of memory. Why isn't anyone talking about this and does it live up to the hype?

"Don't question it!!!" - Err

More about : thoughts

June 23, 2003 8:54:05 PM

G5, eh? I haven't heard much about it. I do know the latest Mac hardware always gets trounced by the latest PC hardware, and I doubt that will change. Maybe they can make that claim because AMD and Intel do not consider multiple processor systems to be 'Personal Computers'. I will look into it now.

<font color=red>Proudly supporting the AMD/Nvidia minority</font color=red>
June 23, 2003 8:56:50 PM

one should remember that in order to get the dual 2GHz proc and 8gigs of ram you have to spend a tad over $8k (ouch).

"Don't question it!!!" - Err
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June 23, 2003 11:40:03 PM

The dual setup isn't too bad at 3k. But getting 8 gigs of ram for any system is going to cost you a huge chunk of change. A 2GB stick of ram is going to run you close to 1k in itself. It's been a while since I last had to look at that stuff but check the prices.

Beauty is in the eye of the beer holder.
June 24, 2003 1:07:13 AM

It's pretty much certain that this "G5" is IBM's PowerPC 970 processor. That being said, with an actually good memory subsystem, this could potentially be a vector processing machine on par, if not surpassing even the P4 in SIMD (it has, theoretically, twice the SIMD throughput as the P4 per clock and we're talking 2 GHz vs the 3.2 GHz on the P4).
It's scalar processing capabilities aren't as impressive but still should be quite good. Perhaps not K8 good but still impressive nonetheless. Considering its PPC ISA and the 4-way superscalar design (or was it 5-way, I forget), it should be a very big contender.
Maybe now, Apple will finally put out a competitively performing machine worth the hefty price they charge.

"We are Microsoft, resistance is futile." - Bill Gates, 2015.
June 24, 2003 2:15:44 AM

The processor looks pretty nice, but here is a question about the front side bus. *http://www.apple.com/g5/*
It has a 1ghz front side bus, but it is only paired with ddr 400. I havn't heard any big new things about ddr 500. That would mean the ram/fsb is running out of sync. In this case the ram would be the bottle neck, so was there really a point in going with a faster fsb? Wouldn't a 800mhz bus *be better*?
June 24, 2003 2:58:12 AM

It's a little vague in terms of the "bus" it's using. It is most likely that that "1 GHz bus" is a hypertransport bus. In which case, even the top end 32-bit hypertransport channel at 1 GHz would transfer like DDR500 would (single channel, not dual channel). If you put dual channel DDR400, your memory would be faster than your FSB.

"We are Microsoft, resistance is futile." - Bill Gates, 2015.
June 24, 2003 4:40:59 AM

They are also extremely lenient in there specs for throughput. They claim a 16GBps throughput on a dual processor system, yet each processor on its own has only an 8GBps throughput.

They have dual 32bit 1ghz busses per processor. They seem to avoid the Hyper Transport label.

<A HREF="http://arstechnica.com/cpu/03q1/ppc970/ppc970-4.html#ls..." target="_new">Ars</A> has a good paragraph on it.

Apple seems to have a tendency to hype things well beyond their theoretical maxium.

Dichromatic for your viewing plesure...
June 24, 2003 5:47:32 AM

I think nobody talks about the G5 because an even more apples to oranges comparison that a p4 vs an AXP.

Or maybe comparing a certain car to a certain plane. Or a certain boat to a guy on rollerblades, errr, nm.

Anyway, I think all the talk you're looking for can be found on the mac zealot sites.

Actually, I've never even looked for it, but is there any mac info on tomshardware?

--Xenius
-non computer guru
June 24, 2003 6:03:54 AM

It's on the front page of CNN.com.

<A HREF="http://forums.btvillarin.com/index.php?act=ST&f=41&t=38..." target="_new"><font color=red>dhlucke's system</font color=red></A>

<font color=blue>GOD</font color=blue> <font color=red>BLESS</font color=red> <font color=blue>AMERICA</font color=blue>
June 24, 2003 6:29:16 AM

Apples will be really good computers if they have as much software available as the PCs. Their hardware, imo, is far better and efficient than PCs. A 64 bit processor with 8.4ghz bandwidth for memory, supporting 8gb of ram sounds awsome. However, if only there is more software available for macs and I'd buy one.
June 24, 2003 6:57:30 AM

Thoughts? It seems to me that this is what Apple needed: a processor and complete architecture package that could compete with Intel/AMD. I've had an iBook for over a year now, and I like it very much, and for what I use it for(at home) the lowly G3-500/384MB is just fine. However, for my number crunching needs, I use AMD and Intel machines (in a cluster config.), and I can't see myself trying to convince anybody to buy me a rack of Macs, until perhaps now... I'd have to look at the pricing, but I'm guessing that it's still too expensive. Final verdict: G5 probably great for home use: easy to use, super-drive with burners for both CDs and DVDs and everything just so damn compatible and well-integrated. Possibly also great for graphics-types, but for serious number-crunching: still too damn expensive. You can get a 16 machine cluster for less than US$20K! How much would the equivalent Mac cost?

:lol:  <b><font color=blue>gnintsakgnirkskir ksron</font color=blue></b> :lol: 
June 24, 2003 10:34:33 AM

the inquirer have an article and link to a hardware site site.. seemsa that mac are making a few err misleading claims and are biasing the spec scores on their site... it seems that the pIV systems are scoring MUCH lower on the mac site than the official spec database scores.. makes it look good though.
June 26, 2003 1:45:36 PM

Their is alot of Mac software out. Plus with OSX alot of Unix software is being converted. If you are a gamer,like me, i would say you are correct. I would consider buying a Mac again if the gaming software was equal to the IBM clones and price/value/preformance is equal.

Pris

I'm not a number, I'm a free man! :mad: 
June 26, 2003 2:39:28 PM

The colleges are gonna be seriously in debt if they buy these 8K machines.

Whether it is good or not, it is seriously not priced accordingly.
I don't care about 8GB memory, a workstation won't even use 1/8th of it, unless the OS interface uses 500MB itself.

Another thing, considering we have a hard time passing 200MHZ FSB, a 1GHZ FSB just like that sounds pretty irrealistic.

--
If I could see the Matrix, I'd tell you I am only seeing 0s inside your head! :tongue:
June 26, 2003 2:46:32 PM

What I find odd, is that although some things are impressive, this is a DUAL processor we are talking about. So while it can beat a 3.2GHZ P4 handily, it does so at a theoretical 4GHZ, no?

If it is single, I apologize for the misinformation.

BTW can someone explain how they reach 8GB/sec with a 32-bit 1GHZ bus?
EDIT: Ok I reread a post here. But how does Dual 32-bit work? Is this DDR like AMD?
--
If I could see the Matrix, I'd tell you I am only seeing 0s inside your head! :tongue: <P ID="edit"><FONT SIZE=-1><EM>Edited by Eden on 06/26/03 10:48 AM.</EM></FONT></P>
June 26, 2003 6:43:16 PM

The ElasticIO interconnect used with the IBM PPC 970 is much like a Hypertransport bus. It is unidirectional point to point. The bus is 32-bits wide in both directions so that amounts to a total of 8GB/sec (4GB/sec in each direction) for a 1 GHz (500MHz DDR) bus. The interesting thing is that the interconnect is used at a ratio to the CPU frequency. Right now, it is clocked at 1/4 the CPU frequency. So a 1.8 GHz PPC 970 would have a 450MHz DDR (900MHz effective) ElasticIO bus, a 2.0 GHz PPC 970 would have a 500MHz DDR (1 GHz effective) ElasticIO bus and a 3.0 GHz PPC 970 would have a 750MHz DDR (1.5 GHz effective) ElasticIO bus. I'm waiting to see if they continue to keep it at that ratio or if they'll increase it. It'd be interesting to see how memory would keep up with that.

"We are Microsoft, resistance is futile." - Bill Gates, 2015.
June 26, 2003 6:57:08 PM

Looking at things right now, IMHO it seems that memory is having a hard time keeping up.

"Don't question it!!!" - Err
June 26, 2003 6:59:35 PM

I was not aware that one could simply add clock speeds on dual processor systems and say that this number means something...I'm unclear as to your "theorical 4GHZ" - do you mean to say that having 2 2GHz processors is like having 1 4GHz porcessor?

"Don't question it!!!" - Err
June 26, 2003 7:02:28 PM

2 processors at 2.0 ghz does not equal 4ghz.
June 26, 2003 7:06:43 PM

this is what I think as well - but I am no expert and not 100% sure.

"Don't question it!!!" - Err
June 26, 2003 8:35:30 PM

Which is why I never said pure 4GHZ.
I mentioned theoretical since in total, you do have 4GHZ clocks, but it is never at the single 4GHZ performance.

To what were you refering when you said this:
Quote:
I was not aware that one could simply add clock speeds on dual processor systems and say that this number means something

?

--
If I could see the Matrix, I'd tell you I am only seeing 0s inside your head! :tongue:
June 26, 2003 8:48:23 PM

I guess I don't understand how a dual system works then because I was under the impression that you would have 2 2GHz clocks - where is this 4GHz clock coming from? Please elaborate.

"Don't question it!!!" - Err
June 26, 2003 9:33:59 PM

If an application has support for multi-threading, every other instruction is sent to the other CPU. This means that 2 x Z Ghz CPUs have the potential to process 2 x Z Ghz 'worth' of instructions (i.e. the amount of instructions that a 2ZGhz single CPU would be able to process in the same time).

However, threading routines are inefficient. When you take hardware limitations into account, multi CPU system rarely hit their potential throughput; most dual CPU systems are 50-70% faster than single CPU ones.
June 26, 2003 10:58:57 PM

I full well know how threads and the like work (since I have written a routine for them in assembly language) but I believe this is simply a language issue as to what people mean and what people say and the interpretation of that.

"Don't question it!!!" - Err
June 26, 2003 11:02:36 PM

in response to the "?"
it seemed like you were simply saying - 2GHz clock + 2GHz = 4GHz clock (even though there is no 4GHz clock present). The only way to even get 4GHz performence would be if everything worked perfectly and there was no interdependence on what was running on each proc. I was just trying to figure out what you were saying.

"Don't question it!!!" - Err
June 26, 2003 11:06:50 PM

Oh, I think Eden meant that a dual cpu 2Ghz system has the potential to do as much work as a single cpu 4Ghz system (assuming that work per cycle rates are the same for both).

Sometimes, people described the peformance increase of a dual cpu system in single cpu terms, such as 2 x 2Ghz translating to 1 x 3.4 Ghz or whatever.
June 26, 2003 11:09:38 PM

in a perfect world (the one that has all those frictionless planes and vacuums)- I guess that kind of performence would happen :-)

"Don't question it!!!" - Err
June 26, 2003 11:17:43 PM

Yep, two plus two never equals four with dual cpu systems. How good can multi cpu systems get though? Is there a point where the marginal performance increase from another cpu simply cannot justify the cost?
June 26, 2003 11:44:37 PM

Indeed, as I said for the second time, THEORETICALLY you have 4GHZ worth of clocks in your system, am I not right? Inside that system, isn't the total CPU clock ticking made of 4 billion ticks?
YES!
That's all I am saying. It does certainly not perform as a 4GHZ would, nor can it ever.

Just like you have theoretically 6.4GB/sec of bandwidth on the P4 but will never reach that. Although here it isn't about the bus being inefficient at outputting the same as one single data rate bus outputting 6.4GB/sec, but rather the application and data flow efficiency.

--
If I could see the Matrix, I'd tell you I am only seeing 0s inside your head! :tongue:
June 27, 2003 1:07:52 AM

I think semantically it’s a bit reaching to say you have 4 billion ticks with two processors running at 2 GHz. It’s like saying my pci bus runs at 5*33=166mhz because I have 5 pci slots. A 4 GHz processor should be able to increment one register 4 billion times. Something two 2 GHz processors cannot do.

I do get what you’re saying though.

Dichromatic for your viewing plesure...
June 27, 2003 2:00:14 AM

I wouldn't be a fool and say you have 4GHZ of performance inside a Dual 2GHZ CPU now would I? :wink:

--
If I could see the Matrix, I'd tell you I am only seeing 0s inside your head! :tongue:
June 27, 2003 4:05:00 AM

This is more or less what I was trying to express. Well put.

"Don't question it!!!" - Err
!