[oldmacfan]

http://www.mc.com/search/productslev...sectionid =12

download said PDF "XR9-418_spec_sheet.pdf"

HMMM. Sorry but I have to go to work now.

[Moogs]

Oooo-K.

[Luca]

Fixed your title. But I am still confused as to why this is so special. At first I misread it as being "750fx," which would have been big news, but this is... uh... totally uninteresting.

[windowsblowsass]

Originally Posted by Luca Fixed your title. But I am still confused as to why this is so special. At first I misread it as being "750fx," which would have been big news, but this is... uh... totally uninteresting.

yeah a 1.8 ghz 750fx would have been big but not as much as a 1.8 ghz 750vx(g3 + altivec)

[oldmacfan]

Originally Posted by Luca Fixed your title. But I am still confused as to why this is so special. At first I misread it as being "750fx," which would have been big news, but this is... uh... totally uninteresting.

I find this interesting because, Apple is only using two 970fx's at this point.
2.0 and 2.5. Although there have been reports of slower chips, this is the first time I have seen them released in any system. I have seen a similar system with a PPC 970 from IBM, but not any PPC 970fx's.

Now think of the implications.

[HOM]

Originally Posted by oldmacfan Now think of the implications.

Isn't the FX line the 90nm part? If so, this could be the same chip that gets shipped in the, god willing, soon to be released iMac G5.

Lower power, less heat, smaller size, and the same speed of the low end PowerMac. This chip almost screams iMac.

[Luca]

Well, the reason I wasn't really impressed was because it's really not hard to downclock a processor. As far as I know (and my knowledge is limited, so correct me if I'm wrong), most processors are made the same way. The ones that are stable when run at 2.5 GHz will go into the 2.5 GHz PowerMacs. The ones that are only stable at 2.0 GHz are only stable at 2.0 GHz and don't work at 2.5, and so on.

Because 90nm processors are cheaper than 130nm processors, and because there are probably a lot of them that don't work at 2.5 GHz, I wouldn't be surprised if they're using 90nm 1.8 GHz processors.

[oldmacfan]

Originally Posted by Luca Well, the reason I wasn't really impressed was because it's really not hard to down-clock a processor. As far as I know (and my knowledge is limited, so correct me if I'm wrong), most processors are made the same way. The ones that are stable when run at 2.5 GHz will go into the 2.5 GHz PowerMacs. The ones that are only stable at 2.0 GHz are only stable at 2.0 GHz and don't work at 2.5, and so on. Because 90nm processors are cheaper than 130nm processors, and because there are probably a lot of them that don't work at 2.5 GHz, I wouldn't be surprised if they're using 90nm 1.8 GHz processors.

I was under the impression that a chip that is not stable at a set frequency when tested is not always going to clock down to a usably stable frequency (ie defects in manufacturing).

It would be like a high performance car motor that was never quite right at high speed so they put a regulator in it so it will only travel at low speed. The problem is that the defect still exists.

Intel is notorious for selling defective chips which are either under-clocked, or have features disabled. They are not the only company to have ever done this, but they have the longest reputation for it.

Also, when a specific chip design is initially manufactured they have a pretty good idea of the range of frequencies that the chips might run at.
If you have a minimal number of defects the chip will scale to a higher frequency, the more defects a specific chip has the lower the frequency that chip can run at down to a point of unusability. Also, underclocking a chip can cause instability, especially if that chip has a larger number of defects.

As for Apple using a 1.8 Ghz 970fx in the PowerMac, or for that matter, a 2.0 Ghz 970fx in the PowerMac, the reports I have seen online seem to state that only the 2.5 Ghz in the PM is a 970fx chip and that the 1.8 and 2.0 PowerMac's are still 970's. Which is why I was excited to see this information.

[oldmacfan]

Originally Posted by Luca Fixed your title.

PS...I was in a hurry to go to work, which I proceeded to get sent home because of over scheduling, but what was wrong with the title?

[Luca]

It had the word "existsts" in it.

[oldmacfan]

Originally Posted by Luca It had the word "existsts" in it.

My bad dyslexic typo, thanks, I thought maybe I got the 970FX part wrong.