A+ 220-1001: Day 2: CPUs

This is post 4 of 18 in the series “a-certification”

System Essentials

CPUs

RISC vs CISC

The 1001-1002 A+ Objectives do not go deeply into this topic. Know CISC from RISC. Additional information here is for your personal knowledge and professional competence.

In the consumer space, CISC came first. But RISC dominated high-end servers and workstations, and was an attempt to improve on CISC. Yes, it’s newer than CISC.

Intel and AMD are punching it out in the CISC space, with really ferocious processors coming to servers, workstations and consumer. Yah horsepower!

But RISC chips are more efficient (power-wise). While they’ve been used in smaller devices, they’re moving up into the consumer space. Apple’s M1 RISC processor punches head-to-head with Intel’s i9 unit in many comparisons (late 2020 as I write this).

ARM has been almost synonymous with RISC, but ARM is actually a design company. They license ARM designs to manufacturers, and most cell phone and tablet chips are ARM-licensed RISC processors.

But there is another. RISC V (or RISC 5) is an open-source design spec. While there isn’t a massive community developing for this design, it’s likely to become much more prominent BECAUSE:

Nvidia is buying ARM! This means they will have a virtual lock on the current ARM/RISC world. https://arstechnica.com/gadgets/2020/09/nvidia-reportedly-to-acquire-arm-holdings-from-softbank-for-40-billion/

An example of RISC vs CISC processing: https://cs.stanford.edu/people/eroberts/courses/soco/projects/risc/risccisc/

RISC vs CISC architecture: https://cs.stanford.edu/people/eroberts/courses/soco/projects/risc/risccisc/

Meet Gary Explains, a Guy Who Explains Things Very Well

8 bit, 16, 32 and 64 bit OSs, processors and system buses

CompTIA primarily wants you to know that 64-bit operation requires a 64-bit CPU, a 64-bit OS and 64-bit BIOS/UEFI support.

Types of Busses in Computers: https://electricalacademia.com/computer/types-buses-computer-architecture/

8 and 16 bit CISC: Intel 8088 and 8086: https://en.wikipedia.org/wiki/Intel_8088

32 bit CISC: Intel i386 / x86 architecture: https://en.wikipedia.org/wiki/Intel_80386

Note that early in the CISC era, up until the Pentium, many manufacturers made “286”, “386” and “486” chips: Intel of course, plus AMD, Cyrix, NEC and others that have disappeared.

64 bit RISC: DEC Alpha: https://en.wikipedia.org/wiki/DEC_Alpha

AMD64 / x86-64

64 bit CISC: x86-64: https://en.wikipedia.org/wiki/X86-64

Why x86-64 isn’t real 64-bit: Extended Memory: https://en.wikipedia.org/wiki/X86-64#Virtual_address_space_details

Processor Product Versions

The 1001-1002 Objectives do NOT require you to know specific processors in depth. Processor principles, however, are critical.

A detailed look at i7 versions from Intel: https://www.intel.com/content/www/us/en/products/processors/core/i7-processors.html

AMD’s path forward: https://www.digitaltrends.com/computing/amd-ryzen-radeon-roadmap/

A third-party comparison of Intel processor lines: https://growtechy.com/intel-processors-comparison/

Meet CPU-Monkey.com, and compare almost all modern processors. Take a look at the Ryzen chips, and also note the Epyc processors: https://www.cpu-monkey.com/en/cpus

Packaging: PGA, BGA, LGA, Slot 1 and Slot A, soldered

The 1001-1002 Objectives do NOT require you to know numbers or names of specific CPU sockets any more. It will be handy to know that Intel sockets change constantly, while AMD maintains socket compatibility across several versions.

ZIF Sockets: Zero Insertion Force: https://www.google.com/search?q=zif+socket

AMD’s AM4 Socket and Chipsets: https://www.amd.com/en/products/chipsets-am4<

Flip Chips: https://www.google.com/search?q=flip+chip&newwindow=1&source=lnms&tbm=isch&sa=X&ved=2ahUKEwi8s-qCzL_tAhVEHc0KHRydA3YQ_AUoAXoECA4QAw&biw=1408&bih=686

BGA: Ball Grid Array: https://www.google.com/search?q=ball+grid+array

Intel rebels against “compatible” processors

Slot 1 and Slot A: https://www.google.com/search?q=slot+1

LGA: Land Grid Array: https://www.google.com/search?q=land+grid+array

BGA: Ball Grid Array: https://www.google.com/search?q=ball+grid+array

Soldered CPUs / GPUs: https://www.google.com/search?q=soldered+cpu

Yes, CPUs and GPUs can melt their solder:

Introducing Louis Rossman and JayzTwoCents. Follow Jay’s attempt to resolder a GPU against Louis Rossman’s advice: https://www.youtube.com/results?search_query=resoldering+a+gpu

Where You’ll See CISC

In almost every desktop (i.e. Intel architecture) and most laptops.
Also most Macs running OS X through 2020.

Where You’ll See RISC

Cell phones
Tablets
Most Chromebooks
UNIX workstations and servers
Very old Macs (OS versions before OS X)
Raspberry Pies
Lots of single-board computers (SBCs)
Oh and also: New Macs with Apple’s own M1 RISC processor!

Processor Advances

Multitasking

Pre-emptive vs. Co-operative

Multithreading

Allowing more than one thread to run simultaneously, eg. Intel Hyperthreading.

Multiprocessing (Multiple Processor Cores)

Putting more than one CPU core on a single die or package.

On-Chip Virtualization

Virtualization in silicon is HUGELY faster than virtualization in software. It must be enabled in BIOS/UEFI, of course on a processor that has this feature.

On-Chip Security and Management

Intel’s vPro is probably the best known management feature within chips, though other manufacturers have similar tool sets.

Features like PAE and NX prevent execution of the contents of some areas of memory, and randomize the location of system files when they’re loaded into RAM (so evil hackers can’t inject code into known locations).

Lots of PCIe Lanes

Cheap processors don’t have many, or any, PCIe lanes. High-end processors have lots of them, some within the processor itself and some for connection to interfaces like PCIe slots, M2 slots, and Thunderbolt ports, and devices like video cards, NICs, etc.