Welcome to the MacNN Forums.

jessejlt · 12:48 PM

Apple has released a preliminary developer specification sheet for the new G5 lineup. The pdf is available HERE

The information is quite informative and an interesting read if you're at all interested in Apple's new PowerMac lineup. I for one am an avid mac user, and cannot wait to get my grubbies on a new G5, so this is indeed a nice read for me. Of particular interest is the use of seperate logic boards for the CPUs, the backwards compatibilities issues for the video cards, and the RAM specifications, in particular, the fact that you must add RAM in pairs.
jesse ;-)

sideus · Jul 3, 2003, 10:02 PM

Look at this, wonder if this may be a problem installing other OS's onto the G5.

jessejlt · Jul 3, 2003, 10:07 PM

Originally posted by sideus:
Look at this, wonder if this may be a problem installing other OS's onto the G5.

From what I hear, if the OS doesn't provide thermal control to the fans, than the fans default to a full-state, where they operate at their maximum speed. Hopefully, destros like YellowDog will add support for the fans when they release their new versions, although I wouldn't count on Debian releasing any sort of thermal control feature, although if the specs for such a thing are provided by Apple, than I'm sure it wouldn't be too difficult to create and add the software yourself.
jesse ;-)

reader50 · Jul 4, 2003, 12:05 AM

Thermal control should have been in the firmware.

However, it will have to default to FULL ON if/when the OS doesn't respond. Otherwise, if you got a system lockup which left the CPUs suddenly in a null loop, the box would burn up.

Dogma · Jul 4, 2003, 06:13 AM

Bleedin thermal management. I always worry about the amount of processor power that goes into the thermal management. It's probably not much, but it would be interesting to see how many clock cycles go into making the fans operate at maximum efficiency.

Hmmm....

I see it can actually take up to 16Gb of RAM (or again, is that just the logical maximum due to what's available - what happens when we start seeing 4Gb and 8Gb memory boards? 32Gb? 64Gb? and on and on...) and not actually limited to 8Gb by software or something. Anyone see anything about the Hard Drives? Will we be able to install anything larger than 250Gb when it's available...

A couple of 500Gb HDs sounds pretty sweet to me, and it's not far off.

Eug Wanker · Jul 4, 2003, 10:45 PM

Originally posted by jessejlt:
From what I hear, if the OS doesn't provide thermal control to the fans, than the fans default to a full-state, where they operate at their maximum speed. Hopefully, destros like YellowDog will add support for the fans when they release their new versions, although I wouldn't count on Debian releasing any sort of thermal control feature, although if the specs for such a thing are provided by Apple, than I'm sure it wouldn't be too difficult to create and add the software yourself.
jesse ;-)

Yellow Dog is taking pre-orders for the G5 already. See here. Hopefully this means they've already taken care of the problem or close to it.

tooki · Jul 5, 2003, 01:08 PM

We're not gonna run into maximum drive size problems for a long, long time, because it went from 28-bit LBA to 48-bit LBA, giving a maximum drive size of 128 petabytes, or 128,000 terabytes, or 128,000,000 gigabytes. I certainly hope we're not still using ATA hard drives by then! Nor do I expect a 128PB drive to be available within the G5's useful lifetime. (It wouldn't, however, surprise me to see drives get that big... in 20 years, we have seen a 50,000-fold increase in hard drive capacity, and I don't expect that growth trend to slow down. Assuming we get another 50,000-fold increase over 20 years, in 2023 we should have 12.5TB hard drives spinning in our Macs!)

My guess is that it takes a tiny fraction of a percent of CPU time, literally something along the lines of 0.00003%, to compute fan speed.

tooki

Eriamjh · Jul 5, 2003, 09:26 PM

Originally posted by sideus:
Look at this, wonder if this may be a problem installing other OS's onto the G5.

I think the key words are "thermal MANAGEMENT". Full on is not thermal management. It is maximum cooling or no cooling.

Apple wouldn't so stupid as to have no cooling the default. Even if the current OS crashes, the hardware must survive. Hence, default has to be some level of cooling.

kkant · Jul 5, 2003, 10:58 PM

Remember how stupid we thought MS was to include auto-running scripts in Outlook, thereby opening themselves up to all sorts of easily spreadable viruses? I kind of see this fan thing in a similar light. Except worse--this time downlading the wrong thing can melt your CPU's!

The worst part is, it seems to me that this could be so easily done with simple hardware. Like a couple thermistors and IC-based amps, to set up a negative feedback loop. I think this was a marketing-driven desicion. It sure sounds cool to say "computer-controlled cooling architecture" rather than "them thar fans".

King_Rat · Jul 5, 2003, 11:09 PM

I was wondering what is up with the 32 bit in / 32-bit out buss on the G5. Does this mean that the G5 must read and write in 32 bit chucks, so that it would take 2 buss cycles to read or write a 64 bit number? It seems to me that, if this is the case, it would really hurt 64-bit performance. On the other hand, if I am reading this right, it could read & write at the same time, which is nice. However, I don't know that much about computer architecture, so I could be wrong on this. Anyone know for sure?

tooki · Jul 6, 2003, 05:01 AM

My guess is that two 32-bit buses (like the G5's) that can communicate simultaneously end up being similar in performance to one 64-bit bus that has to take turns having data flow one way or the other.

tooki

zen · Jul 10, 2003, 08:40 PM

Here's my question:

Why would you *want* to run anything other than Mac OS X on a G5?

Zen

DBvader · Jul 11, 2003, 12:12 AM

i read that a bit ago, and i think i rememeber them showing the standard mouse and keyboard...so no new ones