News for hackers. Stuff that matters.
Re:Using voltage glitching to unleash the A100 in my mining ... by stingraycharles on Wednesday November 11, 2026 @07:53AM (#50452825)
Isn’t this how these things are always done? Same with number of cores in a CPU, the higher core and lower core come from the same fabrication process, it’s just that the lower core CPU had more faulty cores that are disabled.
Re:Using voltage glitching to unleash the A100 in my mining ... by amelius on Wednesday November 11, 2026 @07:55AM (#50452838)
Yes, that's why I question the approach here.

Testing hardware is a complicated matter (you can do a PhD on the topic), and nvidia probably does a better job at it than a hacker in their basement who thinks they can upgrade their GPU for free.

On the other hand ... perhaps a few bit errors is not a problem for AI workloads ... but they could also crash your system ...

Re:Using voltage glitching to unleash the A100 in my mining ... by swiftcoder on Wednesday November 11, 2026 @03:05PM (#50457943)
The good news is that Nvidia did test the hardware, and left the "defective" masks right there in the fuses for us to read. If you have a card that has been fuse-segmented well below its defective part count, you have a product segmentation product on your hands.
Re:Using voltage glitching to unleash the A100 in my mining ... by jamesnorden on Thursday November 12, 2026 @07:42AM (#50466326)
>a hacker in their basement who thinks they can upgrade their GPU for free

Except he literally did.

Re:Using voltage glitching to unleash the A100 in my mining ... by mmo93 on Wednesday November 11, 2026 @07:55AM (#50452839)
Depends a lot on when its from in the product cycle, the yield at the end of production runs are usually so good that it turns into artificial product segmentation
Re:Using voltage glitching to unleash the A100 in my mining ... by BeeOnRope on Wednesday November 11, 2026 @08:00AM (#50452887)
There's an aspect of that, but the primary reason for differences between various CPUs and GPUs which have the same underlying chip is product segmentation.
Re:Using voltage glitching to unleash the A100 in my mining ... by amelius on Wednesday November 11, 2026 @08:57AM (#50453496)
But nowadays they can make much more money with enterprise targeted products.

Which is why I think these devices are more likely to be faulty.

Re:Using voltage glitching to unleash the A100 in my mining ... by lukan on Wednesday November 11, 2026 @09:43AM (#50454051)
Nowdays - but this was a mining card, meaning bought for the crypto boom and before AI.
Re:Using voltage glitching to unleash the A100 in my mining ... by gabrielhidasy on Wednesday November 11, 2026 @12:32PM (#50456025)
The author mentions about 90% yield on getting the full 80GB of memory (in a limited 10 card sample).
Re:Using voltage glitching to unleash the A100 in my mining ... by sidewndr46 on Wednesday November 11, 2026 @09:35AM (#50453948)
Historically, there are products with high enough yield rates that it makes it irrelevant. See ATI Radeon 9500 Pro. A two byte patch in the firmware gives you an ATI Radeon 9800 Pro.
Re:Using voltage glitching to unleash the A100 in my mining ... by LoganDark on Wednesday November 11, 2026 @04:18PM (#50458830)
Sometimes people order more lower-tier chips than there are defects, and then you get fully flawless silicon with some disablement.
Re:Using voltage glitching to unleash the A100 in my mining ... by hypercube33 on Wednesday November 11, 2026 @07:07PM (#50460924)
Used to be now we have chiplets. The defective chips ship as some weird OEM part usually now with parts disabled. Example: Ryzen 5 3500

I don't know what Intel is doing as I quit keeping up with them. I do miss the core unlocked boards that you'd put a 2 core cpu and maybe win the lottery on and get all 4 cores.

Re:Using voltage glitching to unleash the A100 in my mining ... by userbinator on Wednesday November 11, 2026 @10:31PM (#50462719)
This is why, for a while, AMD was selling 3-core CPUs. They were quads with a bad core, which could sometimes be unlocked.