MDD 866 Mods

[IIO]

 
i wonder what the benefit of a higher system bus is when you do not clock the processor higher at the same time.
 

[MacTron]

i wonder what the benefit of a higher system bus is when you do not clock the processor higher at the same time.
 

Do the Math
Calculate the RAM bandwidth (PC-2100 or PC-2700) and the System Bus at 133 or 166 Mhz.
You'll see a bottleneck in the main system bus, this is worst in the 133 Mhz case than in the 166 Mhz case.

DDR 133,  PC-2100 2128 MB/s (2,1 GB/s)
DDR 166,  PC-2700 2656 MB/s (2,6 GB/s)

[UnSoNiC]

Hello,

What about the M8570 (EMC1914) with firewire 800? I have 2 machines, one is 133Mhz, the other is 167Mhz.
How can I mod the 133Mhz machine to become a 167Mhz?

Thank you

[IIO]

DDR 133,  PC-2100 2128 MB/s (2,1 GB/s)
DDR 166,  PC-2700 2656 MB/s (2,6 GB/s)

...which is about ten times more what you need in any of these machines, because thre more you can write and read from memory the more you will also like to have processing power to process all that data.

[MacTron]

... which is about ten times more what you need in any of these machines,

OK. I'll put some extra data:

The Double Data Rate memory bus bandwidth  (from RAM to U2 northbridge):
DDR 133,  PC-2100 2128 MB/s (2,1 GB/s)
DDR 166,  PC2700 2656 MB/s (2,6 GB/s)

The System Bus bandwidth (from U2 northbridge to CPU moule)
MDX 133 Mhz,  1064 MB/s (1.0 GB/s)
MDX 166 Mhz, 1296 MB/s (1,3 GB/s)

The PPC G4 (7455) in the MDDs usually needs around 10 GB/s to run without wait states.
In the Dual CPU modules this is even worst, as this small bandwidth is shared between the two CPUs!

[IIO]

i guess i dont understand the theory. but can you explain it with an example of an application?

say if i want to play audio from a sampler. on a 133 mhz machine i can play some 200 mb/s from RAM - in practice. on a 167 mhz machine i could play some 250, in a machine with DDR3 RAM i could play some 300mb/s.

but in all cases i will not have a computer fast enough to also have one effect plug-in on every channel anyway. so why would i care about the bus throughput?

maybe i fail to see that there are also nonrealtime processing jobs in this world.

[Protools5LEGuy]

Hello,

What about the M8570 (EMC1914) with firewire 800? I have 2 machines, one is 133Mhz, the other is 167Mhz.
How can I mod the 133Mhz machine to become a 167Mhz?

Thank you

AFAIK to mod the motherboard to run 166 instead of OEM133 you have to take 1 resistor of the backside of the motherboard. But I did not ever do that MOD.

i wonder what the benefit of a higher system bus is when you do not clock the processor higher at the same time.
 

Benifit? A dual 866. 866/133= (Aprox) 6.5 multiplier.

If the CPU module were able to work the same in 166...

6.5*166=1079 Hz, so it could be a GHz machine but it seems the cache RAM of the Dual 866 can't go that far.

Here are the modifications needed to change the G4 Bi-867's bus clock from 133 to 167MHz.
You'll note that changing the bus speed to 167MHz would overclock the CPU to over 1GHz. To prevent this, you'll have to change the CPU's multiplier coefficient from x6.5 to x6.

So, 6x166=996, 4 Hz less than a GHz... but...
Should it be quicker than a 6.5*133 machine? Sure it is.

[supernova777]

or u could just buy a better mdd for les then 60$ anywhere in north america
or online

[Protools5LEGuy]

or u could just buy a better mdd for les then 60$ anywhere in north america
or online

In the future, with the success of forums likes this, the number of cheap PPC will be reduced... 

Just look at how much it cost now a 2006 MacBook...

Ppc boards are becoming in collector items, or antiquities.
 
The cost of a 2nd hand G4 cpu module has grown since 2010, and it will be worst.

Chris, it is good for the environment to MOD hardware instead of trashing it.

Anyway, I can't have more machines in my house. 3 PowerMacs and 4 Intels is way too much machines for anyone but a geek-collector. And I will never send to trash ANY PowerPC.

[supernova777]

the difference between 133mhz + 166mhz is an improvement yes.. but imo its nothing too crazy to worry about.. i use machines that have 133mhz bus all the time.. and they are still capable of getting the job done just fine.. g3, sawtooth, quicksilver. 70% of the mac g3/g4s dont have this extreme bus..... its ok;0 its only for those obsessed with having the best

i think its better to focus on using the software !

[MacTron]

its only for those obsessed with having the best

I like to have the best , exactly as most of us. But I'm not obsessed with having it. But I always recommend to buy the best and powerful Mac Hardware Mac Os 9 capable ( the FW400, 166 Mhz Bus MDDs) because nowadays the price is very similar between a G3 or a Yikes with a very bad motherboard or a MDD with one of the best motherboards ever made for a Mac Os 9 machine.
Anyway, each one have its own work flow and each work flow have its hardware bottlenecks. If your workflow implies using 16 or more audio tracks, each one with its effects line, you will need a very fast hard drive and probably Powerful DSP system like Pro Tools. If your work flow rely on 16 tracks of virtual native instruments as mine does, you will need a faster CPU and a fast system bus.

[Protools5LEGuy]

i use machines that have 133mhz bus all the time.. and they are still capable of getting the job done just fine.. g3, sawtooth, quicksilver. 70% of the mac g3/g4s dont have this extreme bus..... its ok;0 its only for those obsessed with having the best

i think its better to focus on using the software !

G3 beige run a 66MHz bus and G3B&W a 100 bus as the PCI G4 and Sawtooth (first AGP). Since Digital Audio or Gigabit Ethernet there is 133 bus(I think it started on DA).

[MacTron]

Another important point is that the CPU speed must be around 4.5 x the bus speed. So for a MDD at 1.25Ghz the optimum system bus should be around 275 Mhz. The presence of the L3 and L3 cache and the 7 stage pipelining, helps to reduce the dramatic impact of the slow 166 Mhz bus, ... but forget about a 133 Mhz system bus ...

The background of this, was the problems that Motorola had to improve the G4, because it was more interested in selling cellulars at its time ...

[Protools5LEGuy]

Another important point is that the CPU speed must be around 4.5 x the bus speed. So for a MDD at 1.25Ghz the optimum system bus should be around 275 Mhz. The presence of the L3 and L3 cache and the 7 stage pipelining, helps to reduce the dramatic impact of the slow 166 Mhz bus, ... but forget about a 133 Mhz system bus ...

The background of this, was the problems that Motorola had to improve the G4, because it was more interested in selling cellulars at its time ...

[youtube]w9VWRB07yqc[/youtube]

[supernova777]

i agree for sure. get the best u can get.. and the budget now for having a 167 is not so different from buying any other mac.. my point is for alot of people that these mods can lead to a nonfunctional computer!! better to just buy the right one.. or use the 867 mdd as it is..
thats just my opinion. u guys go off + mod your motherboards to your hearts content;) i have a mdd 867 sitting downstairs (without a power supply) im not worried about modding it thats for sure.. because i can just get another one for an affordable price if i need.

alot easier to just buy one ... at least where i live.

perhaps im afraid to solder i think its easier to trust the standard config of the machine.. and be happy.. rather then to create instability + wierd problems that can take over your life. video cards i would be much more liekly to try to mod because u can easily replace.. a system board.. im chicken

[MacTron]

BTW: upto Digital Audio 533 all G4s CPUs had an even shorter pipelining!
A 4 stages pipelining!
So this was a real impressive CPU at its time!

... and even today

[supernova777]

protools guy = ultimate steve jobs fanboy
 

[Protools5LEGuy]

protools guy = ultimate steve jobs fanboy
 

Steve NeXTStepped the Macs... We could have CopLand instead of MacOS9 if Steve didn't came out with the NeXT Step OS
http://en.wikipedia.org/wiki/Copland_%28operating_system%29System 7 was ahead of its time, and  Ellen Hancock was wrong on that .

She decided it was best to cancel the project outright and try to find a suitable third-party system to replace it. Development officially ended in August 1996, and after a short search they announced that Apple was buying NeXT in order to use their NeXTSTEP operating system as the basis of a new Mac OS.

Apple should have bought Also BeOS while they finished CopLand and OSX. The first 10.0, Puma and Jaguar are Jokes as OSes, but BeOS wasn't.

Yes, I am a fan on the work he did while the transition from OS9 to OSX making these wonderful machines we use. But he was pushing really hard everyone in the industry to develop for OSX Cocoa not carbonized apps instead of OS9 compatible carbonized apps... The OS9 in the coffin was totally unnecessary to my taste, and even a Bad Strategy for a business. They could be selling OS9 machines longer as they did with Apple II machines on the last 80's and first 90's. Apple had a lot of series of machines pre Steve Jobs, and that "Zen" lineup on products in Steve'Age damaged the life on OS9...     

Also the Steve work on G5 to Intel was awesome. iBooks, PowerBook Ti, iPod, iTunes, iPhone, iPad... Those are wonderful devices, but G4s has an special place for me.

When they went to Intel, there was no need to buy Apple Machines to run Tiger, Leo, SL...

I recognize that have seen every MacWorld since the Steve Jobs back to Apple, some from the NeXT Cube, and the 1984 Macintosh one. What Apple owner didn't do that? Every time I play ..
[youtube]6KJZLiic2F8[/youtube]

makes my DA GHz dual and my MDD 867 run faster and prouder.

[Protools5LEGuy]

Seeing G4 kicking the ass of intel proc. is fun

[youtube]KLWom93pEHY[/youtube]

Steve Jobs running OS9 get nervous...

BTW: upto Digital Audio 533 all G4s CPUs had an even shorter pipelining!
A 4 stages pipelining!
So this was a real impressive CPU at its time!

... and even today

What was the fastest G4 7400?  All 7450 G4 are 7 stage pipeline?

[MacTron]

What was the fastest G4 7400?  All 7450 G4 are 7 stage pipeline?

The G4 500 DP (Gigabit)

... and the Digital Audio G4 533, Mac Server G4 533 (Digital Audio) and Mac Server G4 533 DP (Digital Audio) 533  with the g4 7410 (4 stages too)

All 7450 G4 are 7 stage pipeline?

Yes it is.

Take a look:
Apple Power Macintosh G4 533 (Digital Audio) Geekbench 2 (32):   356
Apple Power Macintosh G4 733 (Quicksilver)    Geekbench 2 (32):   372

Increasing a 38 % the processor speed on the 7450 (quicksilver 733) and only a 4% of Geekbench improvement compared with the 7410 (Digital Audio 533 ) .

Well, the reduced cache memory on the quicksilver also damage its performance...