Do x86/x64 chips still use microprogramming?

Question

If I understand these two articles, the Intel architecture, at it's lowest level, has transitioned to using RISC instructions, instead of the the traditional CISC instruction set that Intel is known for:

http://www.hardwaresecrets.com/article/235/4

http://www.tomshardware.com/reviews/intel,264-6.html

If that's the case, then are x86/x64 chips still microprogrammed or does it use hardwired control like traditional RISC chips? I'm going to guess it's still microprogrammed but wanted to verify.

Answer 1

Microcode has been around for a long time, if that's what you're referring to. So I don't know what the HardwareSecrets article is on about, unless Intel is now building RISC processors on top of CISC processors.

Even the HardwareSecrets article calls them Micro-Instructions. Potato, potahto.

http://en.wikipedia.org/wiki/Microcode

Answer 2

On modern x86 processors, most instructions execute without microcode (*), but some complex or infrequently executed ones do use microcode.

(*) Not to be confused with micro-ops -- in x86 out-of-order processors, x86 instructions are typically decoded into one or more micro-ops which then are queued for execution (sans microcode!) in the out-of-order execution pipeline.

It is also interesting to note that modern x86 processors have a facility to patch/update microcode in order to fix errata in the field.