Hey, I really don't know much about Macs, I just switched...I don't even own one. But say one is a dual 800 mhz, does this mean it has two 800 mhz processors, so it's processing at 1600 mhz? Or that it ihas two 400 mhz processors, so it processes at 800 mhz? Also, are only PowerMacs dual compatible?
Dual Processors?
- Thread starter Xiao
- Start date
hulkaros
The Incredible...
First of all in a Dual 800 there are 2 CPUs each running in 800 MHz...
Now, when you run ANY app that doesn't use the 2nd CPU the PowerMac works like an 800MHz G4... However, when you use an app that can use the 2nd CPU, the PowerMac works more like 1.2GHz more or less... Still, when you overload the PowerMac with apps doing their stuff the PowerMac then too can flex its muscle
Dual is good... Especially, if you can find a cheap one
I hope that you will join our side of the Force, the Bright One!
Azzgunther
Knower of Stuff
What Bob said...
Dual 1.42 ghz system means there are two 1.42 ghz processors and they can theoretically operate around the 2 ghz range.
Dual 1.42 ghz system means there are two 1.42 ghz processors and they can theoretically operate around the 2 ghz range.
lurk
Mitä?
Well theoretically together they run at 2.84 ghz What you are referring to is the problem of parallelizing a single computation across multiple processors where the inter-processor communication and locking issues slow things down. So some photoshop filter may give you real world performance in the 2.5 range assuming 80% efficiency on the second proc. But if you are just doing two unrelated things the efficiency of both processors can easily approach 100% The important thing to do is make sure that the system is well balanced so that there is not too much contention for memory and IO and the like.
It is important not to get too hung up on one given number. I still remember the old vector machine we had at school it used 25 mhz 386 chips and was the fastest thing in the department until the suns broke 500 mhz I think it was. Now fast in that case was measured by total data processed and not the speed of a single given stream.
It all comes back to comes back to balance in the whole machine if you processor is blocking for some reason it doesn't matter if it is blocking at 2 mhz or 5 ghz it is still doin' nothin'.
-Eric
What you are referring to is the problem of parallelizing a single computation across multiple processors where the inter-processor communication and locking issues slow things down. So some photoshop filter may give you real world performance in the 2.5 range assuming 80% efficiency on the second proc. But if you are just doing two unrelated things the efficiency of both processors can easily approach 100% The important thing to do is make sure that the system is well balanced so that there is not too much contention for memory and IO and the like. It is important not to get too hung up on one given number. I still remember the old vector machine we had at school it used 25 mhz 386 chips and was the fastest thing in the department until the suns broke 500 mhz I think it was. Now fast in that case was measured by total data processed and not the speed of a single given stream.
It all comes back to comes back to balance in the whole machine if you processor is blocking for some reason it doesn't matter if it is blocking at 2 mhz or 5 ghz it is still doin' nothin'.
-Eric