A whole class of speculative execution attacks against CPUs were published in 2018. They seemed pretty catastrophic at the time. But the fixes were as well. Speculative execution was a way to speed up CPUs, and removing those enhancements resulted in significant performance drops. Now, people are rethinking the trade-off. Ubuntu has disabled some protections, resulting in 20% performance boost. > After discussion between Intel and Canonical’s security teams, we are in > agreement that Spectre no longer needs to be mitigated for the GPU at the > Compute Runtime level. At this point, Spectre has been mitigated in the > kernel, and a clear warning from the Compute Runtime build serves as a > notification for those running modified kernels without those patches. For > these reasons, we feel that Spectre mitigations in Compute Runtime no longer > offer enough security impact to justify the current performance tradeoff...

ShredOS is a stripped-down operating system designed to destroy data. GitHub page here.