More 90nm PowerPC Notes

[mjtomlin]

Facts, blah, blah, blah

Please people, this is a rumors site. Keep your facts to yourself. This is all about speculation.

Some guy at Apple (at the show) said the rumor sites were way off on what's coming up. So that obviously means 2.8-3GHz PowerMacs. Do I have to draw you a picture or something?

And then of course in the Fall, we'll see the PowerPC 980 @ 65nm running at 3.5-4GHz.

It's all about under-promise, over-deliver. This is IBM, not Motorola! Geesh!

 

[ddtlm]

Henriok:

The "970" that was supposted to go to 2.8 GHz was the 90 nm variant, ie 970FX. The fastest 130 nm 970 I've seen even suggested previously is 2.4 GHz! That would be one hot processor. Not likely!

Since when has any of this been more than rumors and vauge comments by IBM people?

With all due respect, we know almost nothing about the scalability of 970. AFAIK, it has already surpassed its original top speed at 1.8 GHz by 11% to 2 GHz. Going to 3 GHz from 1.8 GHz is a 66% increase and that's too much to ask I think. Why do you think 2.4 GHz is a very attainable speed for the 970 design? Care to elaborate?

Yields on chips improve over time as the maker figures out how to improve the process in small ways and as they correct little problems. I'm sure you know this, Intel and AMD have pushed all of their chips a lot farther by retirement than they would go at launch. For this reason I expect that 2.0ghz is not any sort of ceiling for the 130nm G5. 2.2ghz is pretty much gaurenteed since 2.0ghz was apparently yielding great early on in the game, and I'm guessing 2.4ghz would be pretty doable. 2.6ghz sounds impractical to me.

Intel would **** their pants though If tye arn't already.

I think AMD's almost has them pooping already.

 

[Snowy_River]

Originally posted by army_guy
I find it hard to believe this, in my opinion as I said before the 90nm version is very likely running hotter than the 130nm version due to the process shrink and also the 1u heatsinks, bear in mind any 1u rack server runs hotter than thier bigger cousins.

There's one problem in your logic. The primary cause of heat production has to do with the resistance within the chip. If you shrink the die, then you can get the transistors closer together -> less resistance -> less heat. Yes, it is true that there are some issues that come up around conducting the heat away from the chip, but historically those are dwarfed by the benefits of a smaller die. It is this reduction in heat that allows the processors to be sped up without over heating them. Thus you get a faster processor at the same temperature as you had before by using a smaller die.

 

[ddtlm]

Snowy_River:

The primary cause of heat production has to do with the resistance within the chip. If you shrink the die, then you can get the transistors closer together -> less resistance -> less heat.

Leakage is becoming a major problem at 90nm, which is making Intel's chips generate a lot more heat than they "should". IBM is probably effected by the same thing, to some extent. I'd believe the 90nm G5 produces less heat than a 130nm chip at the same clock, but its probably not as large of a savings as previous process shrinks would suggest.

 

[ClimbingTheLog]

Originally posted by army_guy
...
Who puts a drive that is meant for desktop use (home/games/multimedia/Digital content creation etc....) into a server?
...
Yes SCSI is expensive but how valuable is your data?
Can you put a price on it?
....

RAID.

Most servers will run just fine with a nice RAID-50 setup. The caches are appropriately large and they run one IDE controller per drive so a bum drive doesn't hose the bus.

You see, the problem is SCSI drives are nearly 10x as expensive as IDE drives. So, unless you need massive IO (database server) where SCSI's extra heads help, it's hard to cost justify SCSI drives. Fiber Channel makes it even more irrelevant.

Of course, SCSI drives are almost always more reliable. An IDE drive will last you two years, a SCSI drive, probably 5.

But they're both obsolete in two years anyhow.

If the machine is in a remote location or labor is otherwise prohibitavely expensive (changing drives every so often) and performance isn't paramount, Western Digital offers Server-class IDE drives for about a third of the cost of SCSI.

It's a shame - I like SCSI as a protocol, but the economics aren't there anymore for general server work.

 

[Telomar]

Originally posted by Snowy_River
There's one problem in your logic. The primary cause of heat production has to do with the resistance within the chip. If you shrink the die, then you can get the transistors closer together -> less resistance -> less heat.

Only problem is as you move transistors closer together and shorten gate lengths the electrical leakage through the transistor goes up meaning more heat is produced. This actually goes up with every process shrink and just so happens to go up quite significantly on 90 nm processes.

 

[army_guy]

Yes MORE heat is produced, not only that you to to dissipate it over a much smaller contact area (die size) hence cooling techniques such as liquid cooling/TEC are needed just to reduce the temperature and noise which would be generated with an air cooler. I dont know about everyone else but aircooling went obsolite at 130nm if not before. There is no solution to the heat problem at the chip level, 65nm will be worse and so on. 1st we had no cooling, then passive cooling (heatsink), then active cooling (FAN + Heatsink) now manufacturers have to move to the next step.

 

[army_guy]

Originally posted by Telomar
Only problem is as you move transistors closer together and shorten gate lengths the electrical leakage through the transistor goes up meaning more heat is produced. This actually goes up with every process shrink and just so happens to go up quite significantly on 90 nm processes.

This guy knows what hes talking about!

 

[army_guy]

Pentium Tejas 2.8GHz 90nm sample 775 pin presumably the pentium 5 i think, not really sure but it eats 150W.

Either its a fake or its a multicore (unlikely with only 775 pins?) for it to chew 150W or it could have one MASSIVE CACHE (2Mb @ 2.8Ghz? ) Intel tell me the transistor count!.


No way your gona cool this with an HSF and at the same time expect a noise level less than 45-55db's ,id say minimum water cooling preferably with a TEC.

Not only that either 5 or 6 phase power regulation. Assuming a 1.55V core if not much higher this thing is gona rip with 100 Amps of current requirments.

http://www.anandtech.com/cpu/showdoc.html?i=1943

 

[Henriok]

Originally posted by army_guy
Pentium Tejas 2.8GHz 90nm sample 775 pin presumably the pentium 5 i think, not really sure but it eats 150W.

OMG! Even if it is a prototype, how on earth are they going to get that down to managable levels? And.. Isn't Tejas supposed to be introduced at ~4 GHz? I can't even imgine how much power that little sucker will draw at 4 GHz if it consumes 150 W at 2.8.

 

[wms121]

Hey Arn...is there a 'switch' on the new 970?

..i.e.,

to run "only" 64 bit code..do you need a BIOS switch and/or does the new 90 nm version have one ( from 64/32 mode to "only 64 bit" mode).

Some compilers have internal switches, and/or have to reformat drives..or recode Solid State Disk Drives. 64bit Java can do this in software provided the 'virtual servers' have at least one genuine 64bit capable hard drive.

Any hints on what big Steve is going to announce later this month?

<---embedded slave in motoland

 

[mim]

Originally posted by army_guy
How is Apple gona enter the enterprise market by using ATA drives?

Who puts a drive that is meant for desktop use (home/games/multimedia/Digital content creation etc....) into a server?

I can only see Apple entering the low-end server market nothing more.

You're completely right about the reliability of scsi drives. However, in a raid (5 say) this is really made redundant, as you're considering the reliability of the entire system, which then comes down to how quickly can you get the replacement part, and how quickly you can install it. And on top of that, the G5 servers have pretty damn good (disk) performance for a really good price.

Google have made the case for using cheap, easily replaceable parts to maximise reliability. I think Apple will set a similar trend (yet again) for storage. And yes, I think that lots of enterprise level clients will think that, now the performance is sorted out, xraids will be a really attractive storage solution.

 

[army_guy]

Originally posted by Henriok
OMG! Even if it is a prototype, how on earth are they going to get that down to managable levels? And.. Isn't Tejas supposed to be introduced at ~4 GHz? I can't even imgine how much power that little sucker will draw at 4 GHz if it consumes 150 W at 2.8.

Forget 4GHz, as clock vs power is not linear, for 4GHz maybe 250-350W, even with a 200-250W vapochill wouldnt be able to cool that!!!

 

[army_guy]

Originally posted by mim
You're completely right about the reliability of scsi drives. However, in a raid (5 say) this is really made redundant, as you're considering the reliability of the entire system, which then comes down to how quickly can you get the replacement part, and how quickly you can install it. And on top of that, the G5 servers have pretty damn good (disk) performance for a really good price.

Google have made the case for using cheap, easily replaceable parts to maximise reliability. I think Apple will set a similar trend (yet again) for storage. And yes, I think that lots of enterprise level clients will think that, now the performance is sorted out, xraids will be a really attractive storage solution.

I agree but then again iam thinking of the mechanical issues of an ATA drive under SCSI based conditions. It will come down to how long the ATA drive will last until it fails and how many times that drive will have to be replaced. Still maybe for the lowend it should be OK but anything other than that it wont. Mid/Highend servers are expensive anyway so theres nothing to gain in using ATA drives, thats not the matket apple is trying to penetrate I assume.