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sdhollman

macrumors regular
Original poster
Nov 16, 2005
170
0
Toronto, Ontario
Just wondering if anyone has tried it yet. I know the G5 was next to impossible to over clock because of the nature of that system, but with the Xeon and the Core2 it is wide open.
 

trainguy77

macrumors 68040
Nov 13, 2003
3,567
1
Well the problem with this is finding software that can do it in OS X. As there is no BIOS to do it in. Unless you can find a way to do it in EFI as I recall intel has not opened up EFI for overclocking.
 

dusanv

macrumors 6502
Mar 1, 2006
351
0
I'd say our chances are pretty slim. Intel is overclocking unfriendly. You normally overclock Intel chipsets/CPUs by raising the FSB but our FSB is already at the max (1333) for our chipsets. The other option is to increase the multiplier on the CPU itself but our Xeons are multiplier locked. The only unlocked Intel chips right now are the extreme editions. It's a real shame because these chips clock up really well and Intel yields have been really good.
 

Eidorian

macrumors Penryn
Mar 23, 2005
29,190
386
Indianapolis
I'd say our chances are pretty slim. Intel is overclocking unfriendly. You normally overclock Intel chipsets/CPUs by raising the FSB but our FSB is already at the max (1333) for our chipsets. The other option is to increase the multiplier on the CPU itself but our Xeons are multiplier locked. The only unlocked Intel chips right now are the extreme editions. It's a real shame because these chips clock up really well and Intel yields have been really good.
Well the 965P is a decent overclocking chipset.

http://www.theinquirer.net/default.aspx?article=37465

It seems like EFI is the biggest hurdle. Otherwise you'd be bumping up the Front Side Bus to increase the clock speed.
 

dusanv

macrumors 6502
Mar 1, 2006
351
0
Well the 965P is a decent overclocking chipset.

http://www.theinquirer.net/default.aspx?article=37465

It seems like EFI is the biggest hurdle. Otherwise you'd be bumping up the Front Side Bus to increase the clock speed.

Mac Pro uses the 5000X chipset. 965 is a mainstream chipset for single processor machines. They pushed the FSB on normal DDR2 and we got the FB stuff that's already running super hot at 1333.
 

RottenMutt

macrumors newbie
Feb 10, 2007
2
0
Has anyone been able to over clock a MacPro?
http://forums.2cpu.com/showthread.php?t=77937
the above 2cpu.com link has plenty of information, there are software utilities for both windows and Linux that can access the pll thru the smbus. Intel motherboards have disconnected the pll from the smbus by the use of a transistor, we have figured out just to jumper it but haven't figured out the address which would enable it yet. most of us have motherboards from Supermicro or Tyan which have the pll connected to the smbus all the time.

but ya mac guys and gals would probably just rather be painting daises on your VW Beatles!:rolleyes:
 

dusanv

macrumors 6502
Mar 1, 2006
351
0
[ windows and Linux that can access the pll thru the smbus. Intel motherboards have disconnected the pll from the smbus by the use of a transistor, we have figured out just to jumper it but haven't figured out the address which would enable it yet.

That's cool but our fsb is already at 1333 and I haven't seen any 1666 FB RAM. So what can we do even if get hold of the pll?
 
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