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What difference will 7448 make?
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bossep
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Sep 16, 2006, 11:29 AM
 
I am on a G4 DA equipped with a Sonnet Encore 1.2GHz. I am now tempted to upgrade to a Sonnet dual 1.8GHz but then I read here that the 7448 is on its way. What difference may we reckon to experience with the new chip compared with the one used in the dual 1.8GHz?
     
Lateralus
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Sep 16, 2006, 12:27 PM
 
The four main advances that the 7448 brings over the 7447A are;

1) Decreased power consumption. Which means that even though the initial clock speeds that the 7448 is offered at aren't really any higher than those of the 7447A, the fact that they run cooler will allow upgrade companies to push their overclocking potential that much further.

2) An improved AltiVec engine, which offers Out-of-Order support. Intitial reports seem to show that there's a 10-15% performance boost over the previous AltiVec engine, which was already very capable.

3) Support for bus speeds up to 200MHz. Which really doesn't affect Mac users much since the fastest G4 board is only 167MHz. Still worth noting though.

4) A doubling of the L2 cache to 1MB from 512K and the addittion of ECC.

Of the four above, the two that I consider the most noteworthy are the improved AltiVec engine and the L2 cache. The AltiVec engine because increases in AltiVec performance will bring performance gains pretty much across the board, regardless of any congestion caused by the FSB.

And the L2 cache because the the G4's main achilles heal has always been its starvation by weak FSBs. Doubling the L2 cache means the processor will have to resort to the FSB much less than it currently has to.

I'm personally holding out for 7448 upgrades for my MDD as I don't think the 7447A, at least not at its current clock speeds, would provide enough of a speed boost to bother upgrading.
( Last edited by Lateralus; Sep 18, 2006 at 11:48 AM. )
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bossep  (op)
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Sep 16, 2006, 12:38 PM
 
Originally Posted by Lateralus
The four main advances that the 7448 brings over the 7447A are;

1) Decreased power consumption. Which means that even though the initial clock speeds that the 7448 is offered at aren't really any higher than those of the 7447A, the fact that they run cooler will allow upgrade companies to push their overclocking potential that much further.

2) An improved AltiVec engine, which offers ECC. Intitial reports seem to show that there's a 10-15% performance boost over the previous AltiVec engine, which was already very capable.

3) Support for bus speeds up to 200MHz. Which really doesn't affect Mac users much since the fastest G4 board is only 167MHz. Still worth noting though.

4) A Doubling of the L2 cache to 1MB from 512K.

Of the four above, the two that I consider the most noteworthy are the improved AltiVec engine and the L2 cache. The AltiVec engine because increases in AltiVec performance will bring performance gains pretty much across the board, regardless of any congestion caused by the FSB.

And the L2 cache because the the G4's main achilles heal has always been its starvation by weak FSBs. Doubling the L2 cache means the processor will have to resort to the FSB much less than it currently has to.

I'm personally holding out for 7448 upgrades for my MDD as I don't think the 7447A, at least not at its current clock speeds, would provide enough of a speed boost to bother upgrading.
Thank you for a brilliant reply. I will certainly hold on for the 7448. I guess I will gain even more with my DA compared to your MDD?
     
Lateralus
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Sep 16, 2006, 12:42 PM
 
Hard to say.

Were you on a Sawtooth with a 100MHz FSB, I'd definitely say you had more to gain. But DA v MDD is a little funnier to nail down. Because while the MDD does have a faster bus at 167MHz than the DA does at 133MHz, it relies on DDR RAM. And with DDR RAM being higher latency than the SDRAM of previous systems, and the FSB increasing only marginally and not enough to really warrant the use of DDR in the first place, much of the performance boost that the faster bus should provide is kind of negated.

So, on the whole the MDD architecture is faster than the DA/QuickSilver, but only marginally.
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OreoCookie
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Sep 16, 2006, 01:25 PM
 
What are the exact specs of your machine (RAM, harddrives, SATA cards, etc.)?
A member with an upgraded 1.8 GHz dual G4 is considering a dual G5, so considering the price-point of the 1.8 GHz upgrade, you could probably get a low-end G5 or a new Intel Mac mini for a little more. (Keep in mind that even a Mac mini outperforms your current Mac even if you upgrade it.) Read more in the original thread by Lateralus here.

So make sure to take all costs into account before upgrading and make the decision dependent on whether the rest of the machine is `up to date' and how long you plan to keep it. I would probably not do it and consider getting a Mac mini or a used iMac G5 (if you are on a tight budget) -- depending on how often you use PowerPC apps. Alternatively you could start saving money for your next (Pro?) Mac.
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bossep  (op)
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Sep 16, 2006, 02:02 PM
 
Originally Posted by OreoCookie
What are the exact specs of your machine (RAM, harddrives, SATA cards, etc.)?
A member with an upgraded 1.8 GHz dual G4 is considering a dual G5, so considering the price-point of the 1.8 GHz upgrade, you could probably get a low-end G5 or a new Intel Mac mini for a little more. (Keep in mind that even a Mac mini outperforms your current Mac even if you upgrade it.) Read more in the original thread by Lateralus here.

So make sure to take all costs into account before upgrading and make the decision dependent on whether the rest of the machine is `up to date' and how long you plan to keep it. I would probably not do it and consider getting a Mac mini or a used iMac G5 (if you are on a tight budget) -- depending on how often you use PowerPC apps. Alternatively you could start saving money for your next (Pro?) Mac.
My specs are: 1.5GB RAM, (1x20GB, 1x120GB Seagate, 1x200 GB SATA Seagate, 1x300GB SATA Seagate), Sonnet SATA PCI card, Sonnet USB2 PCI card, Sonnet Encore 1.2GHz. ATA 9800Pro.

Buying a G5 or even a Mac Pro has been considered. Mac Mini is not enough.
     
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Sep 16, 2006, 03:12 PM
 
I see. Besides a cpu upgrade, there is not much you can do to upgrade it …�if you have considered a Mac Pro, I wouldn't upgrade you G4, but wait and get the `middle model'. If you are not in a hurry, you could wait until the Mac Pro is upgraded with quad-core cpus (which will probably debut in Q1 next year).
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bossep  (op)
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Sep 16, 2006, 03:21 PM
 
Originally Posted by OreoCookie
I see. Besides a cpu upgrade, there is not much you can do to upgrade it …�if you have considered a Mac Pro, I wouldn't upgrade you G4, but wait and get the `middle model'. If you are not in a hurry, you could wait until the Mac Pro is upgraded with quad-core cpus (which will probably debut in Q1 next year).
I am most likely going to invest in a MB Pro anyway. I need a portable but don't want to run PSSC2 with Rosetta. Part of my wish to get a 2x1.8 in my G4 is that it would be cool. The big part is that OS X adores 2x and PSSC2 runs better too on 2x. I am not in a hurry.
     
Lateralus
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Sep 16, 2006, 04:00 PM
 
Eh. It seems to me that most people are staunchly anti-upgrade. Even more so now that Apple has transitioned to Intel.

But I'm more of a hobbyist. I love tinkering with and upgrading my computers. It's always fun to push a good piece of hardware to its limits. And I think that's something I'll definitely miss if I ever buy an Intel machine.

With PowerPC, there were always companies, like Sonnet, that came up with ingenious ways of shoe horning a piece of new wave technology into an older, but much loved Mac. It gave Macs an air of invincibility. On the PC side, it was common place to see machines that were just a few years old headed for the trash heaps in hordes. But with the Mac, there was always something cool in the knowledge that 'this old thing' could be turned into a modern, usable, viable machine with just a little work.

With the Intel switch, I think it's fairly safe to assume that Macs will never enjoy the type of longevity that they used to since the upgradeable life of a Mac will essentially be determined by Intel's resolve to develop CPUs for the chipset and socket type in it.

I'll be the first to admit that PowerPC upgrade cards aren't usually the most economical or sensible route to head down. But if you were economical and sensible you would just be using a Windows machine like everybody else.

I say upgrade old faithful, have some fun. Build something unique.
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chefpastry
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Sep 16, 2006, 04:19 PM
 
Although I've purchased a Mac Pro to use as my main computer, if/when a dual 7448 upgrade at or above 2GHz appears sometime within the next 6 months for my MDD, I will take the plunge.
     
bossep  (op)
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Sep 16, 2006, 04:21 PM
 
I completely agree with you about upgrading my Mac. My large challenge was to change all the fans. To get more or less everything out in my hunt for dust. Take out the Power Supply unit and so on.

I am sure Intel Macs will be possible to upgrade. It is much upto Sonnet Nvidia and ATI.
     
bossep  (op)
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Sep 16, 2006, 04:39 PM
 
Originally Posted by chefpastry
Although I've purchased a Mac Pro to use as my main computer, if/when a dual 7448 upgrade at or above 2GHz appears sometime within the next 6 months for my MDD, I will take the plunge.
I will most likely keep my G4 like an old car to have to play with. To me it is a challenge to get my G4 as fast as it is possible and as silent as possible. To get rid of the noise from the fans is nearly as important as to achieve speed.

I want to find out how fast I can go with my current G4?
     
OreoCookie
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Sep 16, 2006, 05:36 PM
 
Originally Posted by Lateralus
Eh. It seems to me that most people are staunchly anti-upgrade. Even more so now that Apple has transitioned to Intel.
Nah, I'm not. But I'd like to keep things in perspective: if somebody decides to upgrade merely to have the fastest computer for the money, (s)he wants to spend, then it boils down to simple numbers. If somebody wants to tinker, then the decision is not just based on money, but on emotional factors -- which is fine by me.

Most people have to/want to base their decision on money (I have to, for instance), hence the numbers speak against upgrading right now. There is an additional factor: all upgradeable PowerPCs are pre-G5s, so they tend to be at least three years old -- in the PC world, that's already pretty much the average life-span. The older a computer is, the less likely you are going to invest money in upgrades. If it were three years ago and beefy upgrades were available for older G4s, the whole calculation would be different.
Originally Posted by Lateralus
But I'm more of a hobbyist. I love tinkering with and upgrading my computers. It's always fun to push a good piece of hardware to its limits. And I think that's something I'll definitely miss if I ever buy an Intel machine.
Actually, I don't think you have to stop tinkering when you get an Intel machine. There is an even larger community of people who work hard to increase performance by just a few percent.
Originally Posted by Lateralus
With PowerPC, there were always companies, like Sonnet, that came up with ingenious ways of shoe horning a piece of new wave technology into an older, but much loved Mac. It gave Macs an air of invincibility. On the PC side, it was common place to see machines that were just a few years old headed for the trash heaps in hordes. But with the Mac, there was always something cool in the knowledge that 'this old thing' could be turned into a modern, usable, viable machine with just a little work.
Sure, the machine is still very useful. And if the OP uses a lot of software which isn't yet available as UB (in particular Adobe apps, office apps should be just fine with Rosetta), there is no big rush to upgrade to an Intel-based Mac yet.
Originally Posted by Lateralus
With the Intel switch, I think it's fairly safe to assume that Macs will never enjoy the type of longevity that they used to since the upgradeable life of a Mac will essentially be determined by Intel's resolve to develop CPUs for the chipset and socket type in it.
Apparently you can swap quad-core Intel cpus into your Mac Pro -- which should be quite an upgrade. But I agree that sockets are not as long-lived in the PC world (and there is a phletora of them anyway).
Originally Posted by Lateralus
I'll be the first to admit that PowerPC upgrade cards aren't usually the most economical or sensible route to head down. But if you were economical and sensible you would just be using a Windows machine like everybody else.
I don't think I would be as productive using Windows or Linux, so no, I disagree. In most businesses, the person using the computer is a lot, lot more expensive than the hardware itself
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chefpastry
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Sep 16, 2006, 05:59 PM
 
Originally Posted by bossep
I will most likely keep my G4 like an old car to have to play with. To me it is a challenge to get my G4 as fast as it is possible and as silent as possible. To get rid of the noise from the fans is nearly as important as to achieve speed.

I want to find out how fast I can go with my current G4?
I gave up trying to quiet down my MDD long ago. I've just learned to live with it and have moved it to a location where it won't bother me as much...
     
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Sep 16, 2006, 09:13 PM
 
Having done the G4 upgrade thing myself...

I think most people are better getting a new machine.
     
Simon
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Sep 17, 2006, 02:36 AM
 
Originally Posted by Lateralus
I'll be the first to admit that PowerPC upgrade cards aren't usually the most economical or sensible route to head down. But if you were economical and sensible you would just be using a Windows machine like everybody else.
I think nowadays it's a myth that Macs are so much more expensive than PCs. Of course the hardware price tag will likely be a bit higher, but if you figure in the included (quality) software, the increased productivity and the much lower support costs, I'm pretty certain you're about even. It's just that when I get a Mac, I suffer a lot less pain.
     
bossep  (op)
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Sep 17, 2006, 03:56 AM
 
Originally Posted by Simon
I think nowadays it's a myth that Macs are so much more expensive than PCs. Of course the hardware price tag will likely be a bit higher, but if you figure in the included (quality) software, the increased productivity and the much lower support costs, I'm pretty certain you're about even. It's just that when I get a Mac, I suffer a lot less pain.
Well after the comparison between a Dell and a Mac Power, can't remember where, we know that the Mac Pro is cheaper.
     
mduell
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Sep 17, 2006, 03:52 PM
 
Originally Posted by Lateralus
With PowerPC, there were always companies, like Sonnet, that came up with ingenious ways of shoe horning a piece of new wave technology into an older, but much loved Mac. It gave Macs an air of invincibility. On the PC side, it was common place to see machines that were just a few years old headed for the trash heaps in hordes. But with the Mac, there was always something cool in the knowledge that 'this old thing' could be turned into a modern, usable, viable machine with just a little work.

With the Intel switch, I think it's fairly safe to assume that Macs will never enjoy the type of longevity that they used to since the upgradeable life of a Mac will essentially be determined by Intel's resolve to develop CPUs for the chipset and socket type in it.
While I've always been amused by the ability to cram a 1+Ghz G4 into a PPC machine that was originally 300 or 400Mhz, or a 500Mhz G3 in a machine that started at 100Mhz, that era of the PPC macs (at least with the pro desktops where most of the upgrading is being done) died about 3 years ago.

As far as I've seen, not a single one of the G5 products can accept any CPU/FSB combination better than the one it originally shipped with.
Contrast that with the Intel Macs, where every (socketed) Yonah product can be upgraded to Merom (and possibly further) and the Woodcrest products can be upgraded to Clovertown (and possibly further).

So the "return to upgradeability" may be on, although its going to be limited to whatever Intel puts out rather than what a third party can hack up.
     
bossep  (op)
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Sep 18, 2006, 07:30 AM
 
Originally Posted by mduell
While I've always been amused by the ability to cram a 1+Ghz G4 into a PPC machine that was originally 300 or 400Mhz, or a 500Mhz G3 in a machine that started at 100Mhz, that era of the PPC macs (at least with the pro desktops where most of the upgrading is being done) died about 3 years ago.

As far as I've seen, not a single one of the G5 products can accept any CPU/FSB combination better than the one it originally shipped with.
Contrast that with the Intel Macs, where every (socketed) Yonah product can be upgraded to Merom (and possibly further) and the Woodcrest products can be upgraded to Clovertown (and possibly further).

So the "return to upgradeability" may be on, although its going to be limited to whatever Intel puts out rather than what a third party can hack up.
It would be interesting to know if the cpu Apple put in a certain machine was the ultimate one or if they could have used something better? It may be completely waste of money and power to put the Sonnet 2x1.8GHz in my G4 DA that is equipped with a 466 originally? I have now 1.2GHz, ATI9800Pro 128MB.
     
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Sep 18, 2006, 08:39 AM
 
The Intel Macs are more upgradable than the old ones
CPU dropin replacement from the minimac to the Pro AnandTech: Apple's Mac Pro - Upgrading CPUs, Memory & Running XP
8 cores in the pro


With the PM 7500 you can upgrade it from a 100 MHz 601 CPU to a 1100 MHz G3 while keeping everyting else. This could not be done on the PC side. CPU and motherboard and memory had to be replaced, but on the other hand this was usually not more expensive than the CPU card for the mac...


No matter the CPU upgrade computers become obsolete anyhow. Imagine a 2 GHz upgrade for 10 dollars for any nubus mac. What use would it have? No OS X, no USB no FW no IDE disks, only SCSI burners. I upgraded my 7200/90 with a 7500 motherboard from ebay and a 200 MHz 604E also from ebay. Later it got a Voodo 3 card, USB card and a G3/350. Now I would not spend money to replace the battery on it.
     
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Sep 18, 2006, 09:49 AM
 
Lateralus, since you seem to know all about the 7448: Has there been any improvement to the caching routines? Intel did wonders on the Core 2 by updating those, and it woudl really help to hide the FSB. What about the L2 cache latency - how many cycles?

Having never owned a G4 and knowing very little of them I would say that generally the 1 MB L2 cache would be a huge help for a CPU that bandwidth-starved.
     
bossep  (op)
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Sep 18, 2006, 09:54 AM
 
Originally Posted by P
Lateralus, since you seem to know all about the 7448: Has there been any improvement to the caching routines? Intel did wonders on the Core 2 by updating those, and it woudl really help to hide the FSB. What about the L2 cache latency - how many cycles?

Having never owned a G4 and knowing very little of them I would say that generally the 1 MB L2 cache would be a huge help for a CPU that bandwidth-starved.
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Lateralus
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Sep 18, 2006, 12:01 PM
 
Originally Posted by P
Lateralus, since you seem to know all about the 7448: Has there been any improvement to the caching routines? Intel did wonders on the Core 2 by updating those, and it woudl really help to hide the FSB. What about the L2 cache latency - how many cycles?

Having never owned a G4 and knowing very little of them I would say that generally the 1 MB L2 cache would be a huge help for a CPU that bandwidth-starved.
"The L2 cache is fully pipelined for two-cycle throughput in the MPC7448. It responds with an 11-cycle load latency for an L1 miss that hits in L2 with ECC disabled and 12 cycles when ECC is enabled. In the MPC7448, as many as six outstanding cache misses are allowed between the L1 data cache and the L2 bus. In addition, the MPC7448 supports a second cacheable store miss. The processors also provide cache locking to the L1 caches so that key performance algorithms and code can be locked in the L1 cache."

MPC7448 Fact Sheet | MPC7448 Product Page
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Sep 18, 2006, 01:26 PM
 
Ah, thank you. Slightly worse than the 7447 then (9 cycles) - I was afraid of that - but the other improvements to the cache should make up for it. Any ideas on what those "Altivec improvements" in the e600 core are specifically?
     
Lateralus
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Sep 18, 2006, 01:45 PM
 
I'm sure there are a number of insignificant fixes, but I have yet to see them documented anywhere, including Freescale's site.

The only one that seems to get any attention is the out-of-order ability.
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