Broadway specs

[theafu]

Memory addressing and caches were tweaked specifially for this chip as I was told.

 

[Mariner]

I'm not sure about current designs where both AMD and Intel are putting much more effort into squeezing every last bit of performance out (and thus have those extra pipeline stages, fast-switch transistors, etc) but the Athlon XPs were able to downclock reliably from over 2ghz to 600mhz and were under 10W at that point, and though not all could, it seemed a significant number could downclock to 300mhz as well were the power draw was between 3W to 4W. Not too bad considering that the processor wasn't designed for low power at all (at least not exclusively).

Haven't heard about any Athlon 64s below 800mhz (maybe 600?), but that's still pretty low. AMD has started to differentiate their processors though, with the ones using fast-switching transistors being only the absolute top end processors, slow switching going to the low voltage and mobile, and then seemingly a mainstream range of processors. The mainstream processors are much cheaper, but at the same clock speeds about 10% to 20% less efficient than the slow switching, and 10% to 20% off the top speeds of the fast switching processors. (and likewise, the slow switching ones can't hit the clock speeds of the mainstream ones)

The current 90nm Athlon 64s can undervolt and underclock pretty well. I've seen quite a few reports of people running these chips at 1000 MHz at 0.8V (standard voltage is 1.35V).

Some of the lower-end Athlon 64s have a TDP of around 32.5W at 2000 MHz and 1.35V. Such a chip running at 1000 MHz and 0.8V would dissipate 5.7W, 800MHz at the same voltage would dissipate 4.5W. Pretty low.

A 750CL produced on 90nm running in the 700MHz region would dissipate a tiny amount of heat which is why I don't believe heat comes into any decisions made by Nintendo if indeed Broadway is based on 750CL and is running at around 700 MHz!

 

[darkblu]

A 750CL produced on 90nm running in the 700MHz region would dissipate a tiny amount of heat which is why I don't believe heat comes into any decisions made by Nintendo if indeed Broadway is based on 750CL and is running at around 700 MHz!

mariner, i don't really think i get what you're saying there.

'their cpu of choice is of particularly low TDP ergo they did not have serious TDP considerations for their application' ? - does not sound right to me.

apropost, here is the latest (from oct 5th) update to the preliminary 750CL datasheet.

one of the new things in there is that the TDP table is already per specific part number. what is unfortunate (for us here, at least) is that the 733MHz part's TDP is still unannounced.

 

[swaaye]

Some A64s can go down to 600 Mhz I believe (800 MHz is very common). Pentium M can do 200 MHz. Both do run those speeds with their power management enabled. Those are the older cores with lower FSB ratings, like Clawhammer and Banias. And some of the Semprons I'd guess.

200 MHz on Banias is not common. Usually Speedstep will drop it to 600 MHz. But I had a Sony note a couple of years ago and it came with Sony apps to control CPU speed. Minimum was 200 MHz fanless from 1400 MHz stock.

 

[darkblu]

Some A64s can go down to 600 Mhz I believe (800 MHz is very common). Pentium M can do 200 MHz. Both do run those speeds with their power management enabled. Those are the older cores with lower FSB ratings, like Clawhammer and Banias. And some of the Semprons I'd guess.

200 MHz on Banias is not common. Usually Speedstep will drop it to 600 MHz. But I had a Sony note a couple of years ago and it came with Sony apps to control CPU speed. Minimum was 200 MHz fanless from 1400 MHz stock.

step-down scalability is all fine and dandy, yet the question still remains: how do the above cores compared watt-wise to IBM's latest G3s? basically, some measure like a mW/MHz in the targetted clock range would be a good indicator.

btw, any idea how, say, a banias would do sleeping? the 750CL datasheet above quotes 1.6W, alas not clear for which particular CL parts.

 

[Fox5]

Some A64s can go down to 600 Mhz I believe (800 MHz is very common). Pentium M can do 200 MHz. Both do run those speeds with their power management enabled. Those are the older cores with lower FSB ratings, like Clawhammer and Banias. And some of the Semprons I'd guess.

200 MHz on Banias is not common. Usually Speedstep will drop it to 600 MHz. But I had a Sony note a couple of years ago and it came with Sony apps to control CPU speed. Minimum was 200 MHz fanless from 1400 MHz stock.

P-M can do 200mhz? Thought the power management only adjusted down to 800mhz for P-Ms. I didn't know it had multipliers enabled to allow any lower than that.

how do the above cores compared watt-wise to IBM's latest G3s? basically, some measure like a mW/MHz in the targetted clock range would be a good indicator.

I wouldn't be surprised to see them do better than IBM's G3 in performance per watt, but that's really irrelevant. They're not comparable cost wise, AMD and Intel are much more restrictive of their IP, and Nintendo really wanted backwards compatibility. An Athlon 64 may beat the G3 in overall mhz and performance per watt/clock, but I believe a G5 may as well, and Nintendo didn't go for a low clocked version of that either. Isn't the die of even a 128KB L2 cache sempron still substantially larger than Broadway? Nintendo is likely buying Broadway at prices Intel or AMD would only sell processors at if they had millions overstock and had to blow them out.

 

[darkblu]

I wouldn't be surprised to see them do better than IBM's G3 in performance per watt, but that's really irrelevant. They're not comparable cost wise, AMD and Intel are much more restrictive of their IP, and Nintendo really wanted backwards compatibility. An Athlon 64 may beat the G3 in overall mhz and performance per watt/clock, but I believe a G5 may as well, and Nintendo didn't go for a low clocked version of that either. Isn't the die of even a 128KB L2 cache sempron still substantially larger than Broadway? Nintendo is likely buying Broadway at prices Intel or AMD would only sell processors at if they had millions overstock and had to blow them out.

yes, i do agree with what you point out as strong restrains for nintendo (price & compatibility) and i was not contemplating the possibility for nintendo to pick a better performance part per se, i was trying to make a wattage-wise parallel, and i just wated it to be as fair as possible -- since we may not see an exact match of clocks between the considered cores, i was looking at a mW/MHz measure.

 

[Fox5]

yes, i do agree with what you point out as strong restrains for nintendo (price & compatibility) and i was not contemplating the possibility for nintendo to pick a better performance part per se, i was trying to make a wattage-wise parallel, and i just wated it to be as fair as possible -- since we may not see an exact match of clocks between the considered cores, i was looking at a mW/MHz measure.

Power consumption doesn't scale linearly with frequency though, power per performance would likely be the best measure to make.

 

[darkblu]

Power consumption doesn't scale linearly with frequency though, power per performance would likely be the best measure to make.

ergo

some measure like a mW/MHz in the targetted clock range would be a good indicator.

otherwise i would generally agree with you that ultimately you want power per performance, but what would you take for definitive performance? - dhrystones? MIPS?

and even if we assume we had the correct performance measure, didn't we already agree that ninty had de fact no options outside of the ppc family for compatibility reasons - so what does that leave us with to compare performance-wise then - moto's G4 and latest high-end IBM's? or a hypothetical 'what-if' G3 part by IBM?

 

[Fox5]

ergo



otherwise i would generally agree with you that ultimately you want power per performance, but what would you take for definitive performance? - dhrystones? MIPS?

and even if we assume we had the correct performance measure, didn't we already agree that ninty had de fact no options outside of the ppc family for compatibility reasons - so what does that leave us with to compare performance-wise then - moto's G4 and latest high-end IBM's? or a hypothetical 'what-if' G3 part by IBM?

I'm not even sure if we could narrow it down as much as PPC, anything that deviated greatly from Gecko (G5) may have broken backwards compatibility. And as always, cost, cost, cost. Supposedly MS got Pentium 3's pretty cheaply initially for the Xbox due to Intel having a surplus, but that was only a temporary situation with low prices. Nintendo's choices, assuming x86 was an option, would have been Pentium 4s (probably couldn't be downclocked enough to have acceptable heat characteristics) or more recently maybe some of AMD's chips, but I don't think AMD is having trouble selling their chips right now even if they are being beaten by Intel. Not like such a situation could have been relied upon either, especially since AMD's downturn is so close to launch. So Nintendo couldn't have purchased any currently produced chips cheaply outside of maybe Pentium 4's/Celerons, which still may not have been cheap enough.

 

[Mariner]

mariner, i don't really think i get what you're saying there.

'their cpu of choice is of particularly low TDP ergo they did not have serious TDP considerations for their application' ? - does not sound right to me.

What I was trying to say (obviously not very clearly!) was that I don't think Nintendo's design criteria heat-wise were low enough that a ~700MHz 750CL on 90nm was the fastest they could manage. I'd have thought that TDP of such a chip would be less than 2W and I can't believe that the design criteria were as low as that. Even 4-5W ought to be very easy to cool even in such a small form factor as Wii. Heat is undoubtedly one factor but if indeed Broadway is what we think it is, Nintendo probably went for such a chip for other reasons also - not just because of the amount of heat it dissipates.

That's probably as clear as mud. Must go now as I'm due to be in a pub about 80 miles away in 2 hours!

 

[crystall]

A few pages ago you can seen that from some estimations (if they are right) the chip can be up to 22mm^ and if like theafu say it has only 512Kb then it can be very well a upgraded GX/CL.

The GX has 1 MiB cache so it would be a shrink to 90nm with half the cache.

If you costumize a GX to be BC with Gekko (and with less L2) it would probably end like a CL, so both info can be right. (IIRC he CL also does have the kind of cache improvements of the GX, right?)

The CL actually has 256 KiB of L2 cache and it is only 2-way set associative, the GX's is 4-way set associative. That said the information on the CL is a little bit thin ATM, one of the improvements the FX/GX had over the CX was a wider 256-bit bus between L1 and L2 which allowed single-cycle transfers of a whole cache-line so this might have been in the Gekko too (and thus in the CL) but I'm unsure about it. The CL datasheet doesn't mention it and IBM's HotChips presentation of the Gekko didn't mention it either so we might never know about it.

 

[Flux]

I was thinking these CPUs can offer the comparable performance with low wattage. I don't believe the IGN specifications at all,too many inregularities.
I mean 50W on a 789MHz 750CL more like 7W? What about $250 pricetag? Thier markup cannot be that large. Another wierd irregularity is that Broadway was finished in may of 2006 and mass produced in september 2006, if it was a higher clocked Gekko why release so late. I believe IBM is not incompetant or unefficient and know how to build thier products. Even if said product was manufactured in 2000.Just doesn't sound right.

I am not saying IGN is lying or IGN sources are "making news", but what do you have thats official?

I mean if Nintendo wants a cheaper machine they can use the 970FX(built in 2004) and save the time and money on rebuilding a 1999 chip for 2006-2007to compete(yes nintendo calls Sony and Microsoft competitors)with new tech.A PowerPC 970FX (@ 1.6GHz 16W) and a small quiet fan is not that expensive.



The company already has a strong grip on certain sectors. It makes the processors for all three of the top gaming consoles: Sony Computer Entertainment's PlayStation 3, Microsoft's Xbox 360 and Nintendo's Wii. These improved chips could help it reach even further.
IBM's 750 CL is a 32-bit chip running at 400MHz to 1GHz, and is intended for high-performance embedded applications, including consumer electronics, storage and imaging. The 970GX supports both 32-bit and 64-bit applications running from 1,2GHz to 2,5GHz, making it appropriate for applications in high-bandwidth data processing or algorithmic computation

http://www.power.org/news/pr/view?it...d5d55a73 6f70

The PowerPC 970GX, a follow-on to the PowerPC 970FX, supports both 32-bit and 64-bit operations. It features the same power capabilities as its predecessor, but incorporates twice the integrated L2 cache at 1MB. The range of frequencies for the 970GX is 1.2 to 2.5GHz, enabling the chip to support high-bandwidth data processing and algorithmic intensive computations, making it suitable for communications, storage, multimedia and graphics based devices.

http://www.eweek.com/article2/0,1895,2023931,00.asp

Oh and hi everyone nice board!


I personally don't believe IGN (like fox news,abc,NYC times ect they can have "suggestions" from thier sponsors.) because without hard proof(IBM specification sheet, a techhead that opened it up or hacked it,nintendo's specification sheet.) I am not going to drink IGN's kool-aid yet. But if it is true they have great reporters and sources.

 

[theafu]

I was thinking these CPUs can offer the comparable performance with low wattage. I don't believe the IGN specifications at all,too many inregularities.
I mean 50W on a 789MHz 750CL more like 7W? What about $250 pricetag? Thier markup cannot be that large. Another wierd irregularity is that Broadway was finished in may of 2006 and mass produced in september 2006, if it was a higher clocked Gekko why release so late. I believe IBM is not incompetant or unefficient and know how to build thier products. Even if said product was manufactured in 2000.Just doesn't sound right.

I am not saying IGN is lying or IGN sources are "making news", but what do you have thats official?

I mean if Nintendo wants a cheaper machine they can use the 970FX(built in 2004) and save the time and money on rebuilding a 1999 chip for 2006-2007to compete(yes nintendo calls Sony and Microsoft competitors)with new tech.A PowerPC 970FX (@ 1.6GHz 16W) and a small quiet fan is not that expensive.



The company already has a strong grip on certain sectors. It makes the processors for all three of the top gaming consoles: Sony Computer Entertainment's PlayStation 3, Microsoft's Xbox 360 and Nintendo's Wii. These improved chips could help it reach even further.
IBM's 750 CL is a 32-bit chip running at 400MHz to 1GHz, and is intended for high-performance embedded applications, including consumer electronics, storage and imaging. The 970GX supports both 32-bit and 64-bit applications running from 1,2GHz to 2,5GHz, making it appropriate for applications in high-bandwidth data processing or algorithmic computation

http://www.power.org/news/pr/view?it...d5d55a73 6f70

The PowerPC 970GX, a follow-on to the PowerPC 970FX, supports both 32-bit and 64-bit operations. It features the same power capabilities as its predecessor, but incorporates twice the integrated L2 cache at 1MB. The range of frequencies for the 970GX is 1.2 to 2.5GHz, enabling the chip to support high-bandwidth data processing and algorithmic intensive computations, making it suitable for communications, storage, multimedia and graphics based devices.

http://www.eweek.com/article2/0,1895,2023931,00.asp

Oh and hi everyone nice board!


I personally don't believe IGN (like fox news,abc,NYC times ect they can have "suggestions" from thier sponsors.) because without hard proof(IBM specification sheet, a techhead that opened it up or hacked it,nintendo's specification sheet.) I am not going to drink IGN's kool-aid yet. But if it is true they have great reporters and sources.

IGN in some cases in regards to Wii specs has been far more accurate than the rampant rumors that turn out to be false or specs that are from outdated SDKs. Only thing I would slight them for is the 16MB edram they reported, but have never really confirmed, where as other aspects what broadway is based from, clock speeds are on the mark from I've been trying to confirm by going to do different sources with accurate info. The interpetation of what Matt knows is what gets under my skin more than anything.

 

[Flux]

IGN in some cases in regards to Wii specs has been far more accurate than the rampant rumors that turn out to be false or specs that are from outdated SDKs. Only thing I would slight them for is the 16MB edram they reported, but have never really confirmed, where as other aspects what broadway is based from, clock speeds are on the mark from I've been trying to confirm by going to do different sources with accurate info. The interpetation of what Matt knows is what gets under my skin more than anything.

Where did you get your information? Developers?


If you are in contact with Wii developers, could you ask them (if they are at freedom to say this) what are the differences in the Wii developement kit and the commercial unit sold to us?

 

[Rolf N]

I was thinking these CPUs can offer the comparable performance with low wattage. I don't believe the IGN specifications at all,too many inregularities.
I mean 50W on a 789MHz 750CL more like 7W? What about $250 pricetag? Thier markup cannot be that large. Another wierd irregularity is that Broadway was finished in may of 2006 and mass produced in september 2006, if it was a higher clocked Gekko why release so late. I believe IBM is not incompetant or unefficient and know how to build thier products. Even if said product was manufactured in 2000.Just doesn't sound right.

Huh? Performance comparable to what? And where do the 50W come from now?
Nintendo wouldn't stockpile chips for years, they start making them as late as possible to reach their desired launch volumes, with mature (cheap, high yielding) process tech.

I mean if Nintendo wants a cheaper machine they can use the 970FX(built in 2004) and save the time and money on rebuilding a 1999 chip for 2006-2007to compete(yes nintendo calls Sony and Microsoft competitors)with new tech.A PowerPC 970FX (@ 1.6GHz 16W) and a small quiet fan is not that expensive.

970 is a large and complex architecture, it's built for high clocks (long pipeline), high ILP and SMT.
The 750CL is simply cheaper to make and needs less power. Besides, if you want a clock-cycle perfect emulation of Gekko, the 970 is the wrong architecture to use.

 

[theafu]

Where did you get your information? Developers?


If you are in contact with Wii developers, could you ask them (if they are at freedom to say this) what are the differences in the Wii developement kit and the commercial unit sold to us?

I've only gone to developers I know to vet the original info which I get which isn't from a dev. Usually I try not to bug certain devs I know about info because they usually can't give it out. Sorry I can't answer your question outright but from ign vids and from what I've read on boards by those who worked with both it seems the commerical version doesn't have issues playing games in regards to control while the debug units do at times.

 

[OtakingGX]

Broadway being a PPC 970 design would also run contrary to what IBM has said about Broadway being 20% more power efficient than Gekko. The 750CL, as pointed out in various threads, can achieve this, but we've yet to see a 970 that can.

 

[Flux]

Broadway being a PPC 970 design would also run contrary to what IBM has said about Broadway being 20% more power efficient than Gekko. The 750CL, as pointed out in various threads, can achieve this, but we've yet to see a 970 that can.

Doesn't explain why it gives off 50W at the clock IGN claims it to be.

And By the way was IBM talking about Watt/per clock efficiency?

Iwata says Wii consumes 50W. FACT.
http://itpro.nikkeibp.co.jp/article/NEWS/20060512/237702/?ST=newtech&P=1

Is on 90nm SOI CMOS process.FACT.
wii.nintendo.com/

built on a 300mm wafer. FACT
http://www-03.ibm.com/press/us/en/pressrelease/20213.wss

built in the same fabrication plant (East Fishkill, N.Y.) as 970FX and CELL. FACT.

About the PowerPC 970FX
IBM's versatile new PowerPC 970FX processor is designed for use in a wide array of applications, from desktops to servers to storage and communications products, which require 64-bit performance and/or low power consumption from a processor. The award-winning PowerPC 970FX is the first chip built using a trio of IBM technology breakthroughs — an industry-first combination of silicon-on-insulator (SOI), strained silicon and copper wiring technologies. IBM is putting this technique to work in volume 90 nanometer (nm) production at its 300mm manufacturing facility in East Fishkill, N.Y.

http://www-03.ibm.com/chips/power/powerpc/factsheets/powerpc970fx.html

maybe its a multicore design? Doesn't explain the die size or the wattage.

 

[theafu]

Broadway during a game runs at 729mhz at 5.5w from what I was told so I doubt it's cpu being the power hog. Would the ram or gpu being taking a lot of power up?