Why not more MP systems?

mailseth

Registered
Remember when adding the second processor on the mac systems was only about $250 extra? Beyond the R & D cost, the only extra cost of a multiprocessor system is for the extra processor and cache (I think). My guess is that apple could go compleatly MP on all of its high end machines (G4s not including powerbook) for only about $200 more than the current price. If Mac OS X can take advantage of MP systems nativly, then what is keeping apple from going compleatly 2 X G4 in the near future?? Or better yet, 4 X G4?? I am looking forward to something like this in the coming year.
 

AdmiralAK

Simply Daemonic
Maybe when G5s come out we can have up to QuadProcessor systems ;)

** please please please pleaseeeeeeee:rolleyes: **
 

Red Phoenix

Registered
Heck, yeah. I'll probably be in the market for a new computer by the time those come out. Excellent...
 
When apple comes out with the G5 dual processor (at least 1Ghz) than they'll get more business from me. It would be sweet if the G5 were also 64 bit. Also another dot release of OS X, maybe 10.2 cuz i still see room for improvement.
 

AdmiralAK

Simply Daemonic
Think of how fast x86 emulators, and emulators will run :D
Aaaahhh my dream situation ;) A mac that does it all! x86, consoles, even older macs at blazing fast speed :D
 

mailseth

Registered
I am hopeing for dual proc as standard on all of the incoming G5 machines. You wouldn't even be able to buy a single proc system, because apple didn't even bother designing it and saved R&D money. And the high end machine is a 8 proc 1.6 GHz G5 system. Ooooohhhhh...... I get shivers just thinking about it.
 

AdmiralAK

Simply Daemonic
Considering the fact that G5s will be at least 1GHz.... 8 processors means 8 GHz or processing power (I really wanna know how many GFLOPS they will have :D) ... lets say 2GB of RAM.... dual cinematic display...aaahhh... I can dream cant I ? ;)
 

rharder

Do not read this sign.
I think the problem is that Motorola can't get its act together to ship enough chips fast enough.

-Rob
 
The G5's are going to cost Apple quite a bit more, too, I'm sure. Which means Multi-proc G4 is much cheaper, and we've all read the report on how Apple will supposedly keep the G4 on the low-end towers, so maybe those 'low-end' towers can be DP G4's, mid-range can be single G5's, and MP G5's for high-end and servers. Gads, Apple could make such a kick-ass server config w/ G5.....:cool:
 

Jadey

sosumi
I remember the beige MP systems where the 2nd processor barely did anything. If you had two 300mhz processors (for example) your system didn't run at 600 mhz, maybe 340mhz. Such a small amount of additional megahertz came out of the 2nd cpu. Is this still the case? If not, does the dual 867mhz G4 actually run at almost 1.7ghz? In Mac OS X do programs still have to be written to take advantage of the 2nd processor? I know in the old MPs again, only photoshop and a small number of other apps could use it. :confused:
 

mailseth

Registered
OS X is a whole new ball game. OS 9 and below was written extremely poorly for MP systems. But OS 10 is based on UNIX. UNIX is coded great for MP systems.

Anyone know the record number of processors in one machine running UNIX? I suspect that it is greater than 100 (or maybe even 1000).

A Dual Processor 800MHz will not run at 1.6 GHz, but it is significantly faster under OS 10 than it is under OS 9.

And no, no one (in theory) ever has to write specific code for MP machines on mac again. We could talk about threading, but that is beyond the scope of this post.
 

Jadey

sosumi
So you still don't get the full juice out of the second chip? Why not? What mhz (or ghz hopefully) does the dual 800 run at?
 

Dog One

Registered
I don't want to sound like I am flaming anyone, but where are you guys getting this notion that dual processor systems speeds are detemined by adding Mhz? A dual 800 system runs at.....surprize 800 Mhz. It only appears to be running faster because there are two processor supporting the system instead of just one. But regardless, the system runs no faster than 800 Mhz.

I hope this clears things up for people. :)
 

Dak RIT

Missing Intelligence
The reason you don't get the full effect of the second processor is because the processors have to share the load by communicating with each other. And they communicate with each other using the system bus. Now while OS X is quite effective at dividing up different threads to be handled by each processor (OS X only supports up to 2 processors right now, not 4), it can't do everything. So, right now I believe the max you can get out of the second processor is somewhere from 75-85%, and 100% from the other. So an application designed to run on MP systems would run about equivalent to a 1.48GHz G4 (although that's a rough estimate). Running multiple applications not designed to take advantage of dual processors would yield lower results, although still respectable.

The G5 will run much better as a MP system than the G4 will, so gains will be even more substantial. I know there were plans to make the G5 a "dual-on-die" chip, which means it could have 2 processors on a single die. Then the processors would communicate at core speed instead of the bus speed, and you would be able to get the full advantage of multiple processors (100% performance out of both). I'm not sure if that was dropped though or not. If it really is a dual-on-die, it will be incredibly impressive, otherwise we'll have to probably wait for the G6.

Within the next 2 years multi-processor systems will become increasingly more efficient and practical, and probably become the norm by 2004. The G7 is scheduled for 2005... won't that be fun :D

Cheers,
Dak
 

mailseth

Registered
Originally posted by Dog One
I don't want to sound like I am flaming anyone, but where are you guys getting this notion that dual processor systems speeds are detemined by adding Mhz? A dual 800 system runs at.....surprize 800 Mhz. It only appears to be running faster because there are two processor supporting the system instead of just one. But regardless, the system runs no faster than 800 Mhz.

I hope this clears things up for people. :)
Sorry 'bout that. I didn't mean to imply that the clock its self would double, I was just trying to simplify my explanation.
 

Dog One

Registered
Dak RIT,

You said:
" So an application designed to run on MP systems would run about equivalent to a 1.48GHz G4 (although that's a rough estimate). "

I am wondering where you are getting this information from.
Again, I have no intention of start of flame war, but 1.48 Ghz out of a dual system is not the case.

mailseth
"Sorry 'bout that. I didn't mean to imply that the clock its self would double, I was just trying to simplify my explanation."

No prob man.
:)
 

Jadey

sosumi
If a dual 800mhz processor system runs still at only 800mhz, why did the old multi processor systems add (minor) numbers to the mhz?
 

AdmiralAK

Simply Daemonic
might it be "perception" Mhz ? :confused:

In any case, when the MacOS and the hardware work perfectly for MP systems I will buy one :D .. image emulation under such a system!!!:eek: It will blow x86 boxes out of the water! :p
 

Dak RIT

Missing Intelligence
The GHz's listed are perceived GHz. It's not a technical explanation, simply one more people can understand. I was simply stating a dual 800 MHz G4 would perform at about 185% (not 200%) the level of a single 800 MHz G4. This roughly compares to a single 1.48 GHz G4 in performance (very roughly, I know, I know). I'm not stating that a dual 800 MHz runs at 1.48GHz, simply using it as a means of comparison (notice I said "runs about equivalent to", I didn't say "runs at").

I'm sure many of the people who read these boards aren't as technically adept as someone with a BS in Microelectronics. There's no need to nit pick.

Cheers,
Dak
 
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