The technical knowledge in it is both out of date, and more relevant than ever.
The particular details are long since irrelevant - even in 1996 optimizing for the 8086 was irrelevant. But the thought process, approach and lessons learnt from optimizing the 8086 are still relevant today.
In fact, they're probably more easily demonstrated through and example using the 8086 than in modern environments. I still use Abrash's S3 FIFO buffer story when I'm mentoring people.
For more up to date technical knowledge, I really liked his software 3d renderer articles. He talks about Pentium 4s and such, which are old of course, but he gives good tips on optimizing for a cache hungry, superscalar processor (which is pretty much relevant today).
I have an old Pentium M notebook with 256 RAM lying around with Linux for optimizing. If you get it to run fast in it, it should run pretty much anywhere. I'm looking to moving to an old netbook though, but I'm not sure because of the architecture of the first Atoms.
If I was optimizing for ARM the RPi would be a great machine :)
The Penitum M is sort of like "the missing link" between old and newer architectures. From it "evolved" the Core Duo brand (I also have one of those around), Core 2 Duo, and Core i3/5/7 architectures. And while there are differences, the M is still similar enough to be representative.
The particular details are long since irrelevant - even in 1996 optimizing for the 8086 was irrelevant. But the thought process, approach and lessons learnt from optimizing the 8086 are still relevant today.
In fact, they're probably more easily demonstrated through and example using the 8086 than in modern environments. I still use Abrash's S3 FIFO buffer story when I'm mentoring people.
So yes, but no.