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Finding a CPU Design Bug in the Xbox 360 (2018)

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Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#21

Post by Aarostotle »

hbn wrote: post #10
timw4mail wrote: post #8

Earlier quoted context omitted.

And there was the same problem with early PS3s, on Nvidia's GPU package...it was a fairly widespread problem at the time.

I don't have any solid numbers on me, but I believe early 360s failing wasn't just widespread; it was straight up most of them dying within the first couple years. It's honestly insane they more or less got away with that. And I guess also speaks to how much Microsoft was killing it in that era that people were willing to go through multiple console RMAs (which I heard was a terrible, slow, and unreliable process) to…

Simple answer: Halo 3.

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#22

Post by Narishma »

Grazester wrote: post #20
cptskippy wrote: post #16

Earlier quoted context omitted.

> It is interesting that IBM dominated this generation of consoles, and was vanquished in the next. IBM's Power was the only logical option at the time. These consoles were being designed around 2000. Intel and AMD weren't partnering on bespoke CPUs at that time. I don't even think AMD would have been considered a viable partner. Neither had viable 64 bit options and part of console marketing at the time was the ever…

By the way, the AMD athlon 64-bit launched 2003. The PS3 launched in 2006. I had an AMD64 bit process in my laptop in 2005. What wasn't viable?

Yeah that part didn't make sense, not to mention that neither the PS3 nor the 360 were running 64-bit software. They didn't have enough memory for it to be worth it.

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#23

Post by Moosdijk »

rwmj wrote: post #9
timw4mail wrote: post #8

Earlier quoted context omitted.

And there was the same problem with early PS3s, on Nvidia's GPU package...it was a fairly widespread problem at the time.

And Apple iBook G3s too. There's a whole thing with owners reflowing the GPU: https://www.instructables.com/Fixing-the-infamous-iBook-scre...

I had to do this with my MacBook Pro models early 2015 and late 2017.

It seems like there was a period in time when solder just wasn’t done well, it seems like.

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#24

Post by chasil »

Grazester wrote: post #20
cptskippy wrote: post #16

Earlier quoted context omitted.

> It is interesting that IBM dominated this generation of consoles, and was vanquished in the next. IBM's Power was the only logical option at the time. These consoles were being designed around 2000. Intel and AMD weren't partnering on bespoke CPUs at that time. I don't even think AMD would have been considered a viable partner. Neither had viable 64 bit options and part of console marketing at the time was the ever…

By the way, the AMD athlon 64-bit launched 2003. The PS3 launched in 2006. I had an AMD64 bit process in my laptop in 2005. What wasn't viable?

I have some confidence that AMD's acquisition of ATI had a huge impact.

That allowed both a CPU and an advanced GPU to be on the same die.

They also wisely sold Global Foundries, and were able to scale with TSMC.

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#25

Post by sidewndr46 »

Narishma wrote: post #22
Grazester wrote: post #20

Earlier quoted context omitted.

By the way, the AMD athlon 64-bit launched 2003. The PS3 launched in 2006. I had an AMD64 bit process in my laptop in 2005. What wasn't viable?

Yeah that part didn't make sense, not to mention that neither the PS3 nor the 360 were running 64-bit software. They didn't have enough memory for it to be worth it.

you don't need memory to make 64 bit software worth it. Just 64 bit mathematics requirements. Which basically no video game console uses as from what I understand 32-bit floating point continue to be state of the art in video game simulations

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#26

Post by esaym »

chasil wrote: post #5
vondur wrote: post #4

Earlier quoted context omitted.

I thought the design flaws of the Xbox 360 cooling system had more to do with Microsoft than any inherent design flaw by IBM. I assumed that switching to x86 processors let Microsoft leverage their native developer tools from Windows which helped developers.

The main issue was revealed to be solder. "Microsoft did not reveal the cause of the issues publicly until 2021, when a 6-part documentary on the history of Xbox was released. The Red Ring issue was caused by the cracking of solder joints inside the GPU flip chip package, connecting the GPU to the substrate interposer, as a result of thermal stress from heating up and cooling back down when the system is power cycled…

When did the industry transition to different/lead free solders? Wonder if that was part of the issue?

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#27

Post by Tuna-Fish »

brcmthrowaway wrote: post #17
NooneAtAll3 wrote: post #13

unrelated, but recently XBox One was hacked for the first time https://www.youtube.com/watch?v=FTFn4UZsA5U

How does XBox get hacked when it uses Secure Boot?

Voltage glitching. An outside attacker who has direct, extremely fine-grained control over the power supply to the chip can cause it to brown out for one instruction cycle, preventing a result of an instruction from being written.

With enough sophistication, physical access is more powerful than root access, no exceptions.

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#28

Post by duped »

sidewndr46 wrote: post #25
Narishma wrote: post #22

Earlier quoted context omitted.

Yeah that part didn't make sense, not to mention that neither the PS3 nor the 360 were running 64-bit software. They didn't have enough memory for it to be worth it.

you don't need memory to make 64 bit software worth it. Just 64 bit mathematics requirements. Which basically no video game console uses as from what I understand 32-bit floating point continue to be state of the art in video game simulations

Fundamentally it's still a memory limitation, just in terms of memory latency/cache misses instead of capacity. If you double the size of your numbers you're doubling the space it takes up and all the problems that come with it.

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#29

Post by monocasa »

esaym wrote: post #26
chasil wrote: post #5

Earlier quoted context omitted.

The main issue was revealed to be solder. "Microsoft did not reveal the cause of the issues publicly until 2021, when a 6-part documentary on the history of Xbox was released. The Red Ring issue was caused by the cracking of solder joints inside the GPU flip chip package, connecting the GPU to the substrate interposer, as a result of thermal stress from heating up and cooling back down when the system is power cycled…

When did the industry transition to different/lead free solders? Wonder if that was part of the issue?

Yeah, it was the transition to RoHS.

Re: Finding a CPU Design Bug in the Xbox 360 (2018)

#30

Post by sidewndr46 »

duped wrote: post #28
sidewndr46 wrote: post #25

Earlier quoted context omitted.

you don't need memory to make 64 bit software worth it. Just 64 bit mathematics requirements. Which basically no video game console uses as from what I understand 32-bit floating point continue to be state of the art in video game simulations

Fundamentally it's still a memory limitation, just in terms of memory latency/cache misses instead of capacity. If you double the size of your numbers you're doubling the space it takes up and all the problems that come with it.

No it isn't. The 64-bit capabilities of modern CPUs have almost nothing to do with memory. The address space is rarely 64 bits of physical address space anyways. A "64-bit" computer doesn't actually have the ability to deal with 64 bits of memory.

If you double the size of numbers, sure it takes up twice the space. If the total size is still less that one page it isn't likely to make a big difference anyways. What really makes a difference is trying to do 64-bit mathematics with 32-bit hardware. This implies some degree of emulation with a series of instructions, whereas a 64-bit CPU could execute that in 1 instruction. That 1 instruction very likely executes in less cycles than a series of other instructions. Otherwise no one would have bothered with it

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