Post by originalmacnut on Sept 30, 2008 16:02:43 GMT
Got a question for all you Overclocking Guru's out there. I have a DA with a 733 XPC7450 chip, I have taken it up to 800, then to 867. At 867 it's very stable, not to hot nor does it have any problems at all.
The plan was to take it to 933 or 1g, but there is a issue, After Testing the chip.
Problem. ( Stock Vcore is 1.9v )
933 + Vcore @ 1.9v = no boot, with Chime
933 + Vcore @ 1.95v = Video corruption. no boot
933 + Vcore @ 2.0v = Tries to load but hang at the Mac screen, then load into console command mode. ( boot to command line only, hangs at mac-boot )
These chip are rated for a max Vcore of 2.1v, but with air cooling a bit scared of taking it that far. Though at 2.0 Vcore, the hintsink isn't that hot. Has anyone pushed these chips to 2.1v with stock cooling? and would you try taking it to 2.1v?
If I can get a stable boot the cooling will be upgraded, it's more of pushing it to hard on voltage I'm worried about. As the DA is a Perfect Machine, with all the extra's when I bought it.
Hey originalmacnut: Like any mac CPU, you can overclock to a point, but then you run into the same problems everyone else runs into. Overclocking the chip, and finding the suitable steps to overclock the L3 Cache also. Best guides that might be able to help you would be this... xlr8yourmac.com/g4articles.html They have lots of info regarding the G4 CPU's
Well, I set the Vcore to 2.1v. This works on a cold boot for about 5 minutes or so, then becomes unstable with kernel panic trace stack. I'm thinking it's do to the L3 cache, I've looked, but can't find anything related to the Cache, other than the Chip can handle 2.9v but are set to 2.5v Thanks for your reply guys, as I think I'm done for now. Looks like I'm stuck with 867MHz, but hey, I did get it to boot into osx @ 933 Mhz. So now, either the cache needs Coolers, or more Voltage? What you guys think? I'll post PIc. of the success boot at 933 MHZ, Odd thing is, It boot Leopard install disc. without a panic, to scared to try a full install at 933. Will try once install at 867, could be Tiger install. -OMN
ok, then if it's the QS 733 non L3 then yes, some say online you can push them to a 933. I myself have the same processor, but it only liked going to 800. 867 and 933 choked out my processor. Hence why i have a 1.4 in my QS now. If you want, once my GST comes in, if you somehow fry your cpu, you can have mine.