3 ms·

Adittionally, probably the most famous example is the Celeron range. Celerons were originally Pentium IIs with large segments of the cache fused off, unusable

Adittionally, probably the most famous example is the Celeron range. Celerons were originally Pentium IIs with large segments of the cache fused off, unusable due to defects. However they turned out to be so popular that Intel started to disable the cache of otherwise good cores, and then later began specifically fabbing them, to meet the demand.

pjtaipale 15y ago
For me, the most famous example is DRAM chips in Sinclair ZX Spectrum. Sir Clive got them cheap because they were ones rejected at the production test. Spectrum issue 1 48 K model used 64 kbit chips where one half was broken, and the motherboard was then wired to only use the other half. That was a time when hardware, particularly memory, was expensive. This was in 1982.
InclinedPlane 15y ago
Not exactly. Celerons began as straight up Pentium IIs designed to operate without any L2 cache. They didn't have great performance but were crazy cheap to make and super easy to overclock. Then they started cramming in just a little bit of on-die L2 cache (about 1/4 of the minimum for a regular Pentium II) to help out performance. This turned out to be wildly successful, and eventually this formulation (one chip with on-die L2 cache) became the predominant design for the mainline Intel micro-processors. Afterwards the Celeron family of processors were identical to retail Pentium/Core cpus but with sections of cache disabled, reduced clock rates, etc. (either due to binning by defects or intentional deactivation). Interestingly, Intel now offers "upgrade cards" for low-cost CPUs whereby components are deactivated via firmware or suchlike and special codes can be entered into the bios screen to turn them on (for a price, of course).
- reitzensteinm 15y ago
  Ah, it seems you're right - thanks for correcting me.

3 ms·

Adittionally, probably the most famous example is the Celeron range. Celerons were originally Pentium IIs with large segments of the cache fused off, unusable

by reitzensteinm 15y ago

pjtaipale 15y ago
For me, the most famous example is DRAM chips in Sinclair ZX Spectrum. Sir Clive got them cheap because they were ones rejected at the production test. Spectrum issue 1 48 K model used 64 kbit chips where one half was broken, and the motherboard was then wired to only use the other half. That was a time when hardware, particularly memory, was expensive. This was in 1982.
InclinedPlane 15y ago
Not exactly. Celerons began as straight up Pentium IIs designed to operate without any L2 cache. They didn't have great performance but were crazy cheap to make and super easy to overclock. Then they started cramming in just a little bit of on-die L2 cache (about 1/4 of the minimum for a regular Pentium II) to help out performance. This turned out to be wildly successful, and eventually this formulation (one chip with on-die L2 cache) became the predominant design for the mainline Intel micro-processors. Afterwards the Celeron family of processors were identical to retail Pentium/Core cpus but with sections of cache disabled, reduced clock rates, etc. (either due to binning by defects or intentional deactivation). Interestingly, Intel now offers "upgrade cards" for low-cost CPUs whereby components are deactivated via firmware or suchlike and special codes can be entered into the bios screen to turn them on (for a price, of course).
- reitzensteinm 15y ago
  Ah, it seems you're right - thanks for correcting me.