XBONE having problems with eSRAM yield. Crazy Buttocks confirms.

[Pemalite]

kitler53 said:

Porcupine_I said:

kitler53 said:
wouldn't low yield just mean low shipment numbers at launch until it is figured out?

probably, but if you want high shipment numbers at launch and a downgrade of the clockspeed can fix the problems of the faulty chips, you could also go down that route.

problem is, if you do that you can't fix it later.

i was going to rebuttle with that but you beat me too it.  downclocking now would really fuck up all the games currently in developement and limit future potential (without cloud assist which if I were MS I wouldn't rely on after the always online fallout).

 

also, it's just a little air-born..

Also "Downlocking" doesn't actually fix yield all yield problems, it's a very complex problem.

Sometimes you have units on a chip that are just simply far to damaged to do anything with, not even down-clocking or throwing more voltage at the problem can solve it.
AMD, nVidia, Intel and all the other semiconductor manufacturers have a solution to that however, they disable the non-functioning portions of the chip and sell it as a cheaper product, I.E. Instead of a Quad Core, it's now a Dual Core.
They can then harvest more working parts of a wafer, again that's not viable as all the hardware across all the consoles needs to be identical.

What Microsoft should have done (If this rumour is indeed true) is throw more transisters at the problem and built more redundancy into every chip, so if a Core or a Pixel pipeline is buggered, they have some spares, I would actually be surprised if they didn't do that, unfortunatly because it drives up die-area it also drives up costs and the Xbox One's Die-Size is already rather monolothic due to the eSRAM.

Now, when a chip has allot of leakage (Should not really be a problem now on a mature 28nm manufacturing process) they simply underclock or throw more voltage at the problem, unfortunatly underclocking affects all the consoles as they have to keep the hardware the same.
Over-volting won't work either as consoles have cooling systems that are engineered for a specific TDP.

kitler53 said:

i've been told MS have mountains of money to ensure that the xbone is succesful.  wouldn't taking a high cost per chip for a couple of months until you can get better yields be worth it?  its not like this kind of issue should take years to figure out.  faced with missing this holiday (giving ps4 a head start), down specing the system (risking delays to launch games that would need to be modified for the change in specs), or taking a short term financial hit,..  i'd take the hit and hide it in MS's billion+ quarterly profits.

Nah. 28nm that the Xbox One is using is fairly mature, they would need to do a re-spin of the silicon and re-work the chips to get better yields and maybe throw more redundancy in the chips for when something doesn't function, but that costs more transisters and hence drives up costs.

However, if AMD is handling the manufacturing side, I'm pretty sure they have a deal where they only pay for working chips anyway, they might just have to fire up some more production lines to throw more chips out, it also means supply might be limited on launch, provided this rumour is true.