> Intel spends nearly 40% of the core’s die area to implement wide AVX-512 execution, so Knight’s Landing gets some incredibly high throughput for a low power architecture. In fact, it almost feels like a small OoO core built around feeding giant vector units
Well said!
There's some interesting details here. I love how the article tests SMT1 (aka no SMT), SMT2, and SMT4, and shows how things change. The re-order resources getting subdivided as SMT scales up is obvious but a neat hack, a real neat hack, for repartitioning core resources- on a core (Atom) that wasnt doing reordering much at all, at that point.
Also a good reminder that this almost 10 year old chip was using DDR4. I'd forgotten that DDR4 has been around for so so long!
The chip has some really monstrous capabilities. Modern flagship consumer GPUs are hitting the 1Tbps mark in memory bandwidth. AMD's upcoming Navi 3 has 96MB of L3 cache good for 5.3TB/s. Meanwhile, here's a chip that's 10 years older that has 16GB of onboard DRAM that C&C gets up to 4.5TB/s. Damn ya'll. And with huge AVX-512x2 per core, as mentioned in the top quote... this thing was such a wonderful & fascinating beast.
I didn't realize the previous incarnation- which I bought used/hella-cheap a long time ago & wanted to toy with but never did- was P54C based, aka an original-ish Pentium. That's wild.
This article is just so good. On and on, with every little characteristic and quirk. This is like a perfect "Speaking for the Dead", out of Enders Game. Alas that the world just wasn't awesome enough to put this shit to use at real volume. It's like an ultra-flexible on-the-fly reconfiguring DSP?