Monday, April 13, 2015

Hardware basics according to me



I helped a friend last week assemble a bran-new computer and he was interested to learn how it's done.
A quick search on the Google machine showed mediocre results for learning PC basics so I thought a quick write-up would be in order. I started tinkering on computers when I was in Jr.-High, and in high school I built my first computer. It was just school-tech leftovers that they used for the students to practice on but I had a pretty good start to this hobby of mine.

There are two parts to a PC: hardware and software. I'm not much on software and most of it these days is pretty user-friendly and simple so I'll focus on hardware for this write up. Basic parts for a system include the Motherboard, the PSU, CPU, the RAM, the GPU, the HDD, and the optical drive or ROM.





 The Motherboard is where it all comes together. Its what flows all the data from on center to another. There are various ports, expansions, jumpers, chips, etc. Main components of the motherboard are the socket, the DIMMs, the IO, the PCI expansion ports, chipset, SATA, IDE, various headers, jumpers, and a battery. They come in various form factors and vary widely in features and capabilities.


Pictured above is the MOBO's Model Number (very useful for finding specs drivers and QVLs)
The socket is where the CPU installs. You can only install compatible CPUs into a socket.


 
DIMMs are where the RAM installs.

  
The IO are the ports on the rear of the motherboard for plugging in peripherals such as your keyboard, mouse, speakers, etc.


The PCI expansion slots are where additional functionality can be installed such as discrete graphics, TV cards, WIFI cards, etc. There are PCI, PCIe, PCIe4x, PCIe16x, AGP, PCIe2.0 and PCIe3.0. PCIe16X, 2.0 and 3.0 are backwards compatible. Your card will run properly, but the bandwidth is dumbed down to match the slot it's in.  (Pictured above are PCI slots and the brown one is an AGP)


The chipset is the main chips that direct the flow of data between the ROM, RAM, and CPU.  

There are various headers for USBs, Audio, fan headers, and power switches with their associated LED indicator lights. The USB headers are used for front mounted USB ports and card readers. For MOBOs with built-in audio you can connect front audio jacks to those audio headers. Then there is the header for the power switch, reset switch, power LED and HDD led.

There usually are various jumpers for certain feature control. I have a MOBO that allows you to limit CPU FSB speed with a jumper. Most MOBOs have jumpers to adjust power output to USB headers. One of my PCs I can charge my cell phone with the USB even if the PC is powered down. And also another important one is the BIOS reset jumper. Helpful if your BIOS become corrupted or you change a setting that doesn't work out.

The battery is important. It may just be a stupid little button battery but it's what keeps the system clock running, and the bios settings saved. I have a MOBO that I used for a while, then tucked back in the box for a later day. I recently got it out to use it once more and when I booted it up it had it's old settings still and the time was correct.

Two Fan headers (the white plugs)

SATA and IDE are the interfaces in which the storage devises are controlled. SATA is the newer, faster interface. IDE (or PATA) are the old interfaces. They were the big ribbon cables that are so obnoxious.

SATA (top) IDE or PATA (bottom)

The difference between an old IDE ribbon cable and a newer SATA cable.

Pictured above is the BIOS chip


I neglected to take a photo of a PSU, so apologies for that.

The PSU is simply the power supply (unit). They can come in several form factors and typical power output is read on the PSU as watts. There are standard, semi-modular, and fully-modular PSUs. A PSU can have any number of power outputs on it. Motherboard power, CPU power, Molex connectors, SATA power connectors, PCIe power connectors, etc.  Modular models help keep the interior of the case clear of a mess of wires.  There are also power efficient models rated bronze, silver, or gold for those of us interested in saving some money on our electric bill. I see them as a good option if the PC is in use often, runs all the time as a server, or if you have a computer lab and run many PCs. They are also more expensive. Hence why I've never owned one. That, and my PCs or only powered on for as long as I use them.

 
 Old AMD Athlon XPs on top, Pentium 3 and a Pentium Celeron in the middle and two Pentium 4s on the bottom.

The CPU is the brain of the Motherboard. Raw data goes in and calculated data comes out. When you execute a program the data is received by the CPU as a set of instructions. The CPU executes those instructions. There are single core, duel core, triple core, quad core, six core, and 8 core CPUs. Some CPUs have integrated graphics processors and AMD makes one with 12 cores. 4 CPU cores and 8 GPU cores. CPUs can only go in their associated sockets. AMDs series of am2, AM2+ and AM3 sockets are backwards compatible. You may use an AM3 processor in an am2+ socket, it just dumbs down the Front side bus speed to the socket's limit. There are two speeds to consider with CPUs. The CPU's speed itself, and the Front Side Bus speed. The speed of the CPU is how fast it can make calculations or run sets of instructions, or a better way of saying it is how quickly it can process data. General rated in ghz. The front side bus is how fast it can transfer that data to other parts of the motherboard. The more cores mean the more instructions or calculations it can do at a time. The faster the ghz the faster it makes those calculations or finishes those instructions. A duel core CPU can accomplish a task faster then a faster rated single core because it can have 2 cores work on it together. The enemy of a CPU is heat. CPUs come with coolers usually made of aluminum or copper or both. They draw the heat off the CPU chip so it can maintain it's stability. Sometimes if your computer is running sluggish or crashes for no apparent reason it can be as simple as opening up the computer and removing dust build up. I'm a bit of a nerd for air-cooling and the PC I'm building now has 9 fans and the biggest CPU heat-sink I could find that was both well rated and affordable.

The RAM is very important to the CPU. When the CPU is running instructions or calculations, it stores the data in the RAM. Random Access Memory. One of the best ways to speed up a computer is to add more RAM, or faster RAM. There are a few types of RAM, and none are compatible with each other (DDR, DDR2, DDR3, SDRAM, DRAM, and so on). RAM comes in different speeds measured in MHz. The more RAM, the more it costs, same with the faster the RAM. I think DDR4 RAM hit the market recently. 32 bit versions of Windows can only recognize up to 3 gigabytes of RAM. 64 bit versions don't really have a limit. I've seen motherboards with support for up to 64 gbs of RAM. I personally don't have a computer that currently runs more than 4 gbs. Though I plan to have 8 when my Frankenputer MKIV is complete. I could also easily double the RAM in my wife's PC to 8 gbs.

RAM pictured below:
The top two are DDR2 RAM sticks and the bottom 2 are PC133 Ram sticks.

Notice how the second and fourth one are single channel (RAM chips on only one side of the stick)

The GPU is the graphics processing unit. Many motherboards have some sort of on-board graphics built it and are fine for basic computer use or use that does not denote heavy graphical requirements. Some graphics GPUs are built into the CPU and can perform better than those built into the MOBO. Both are called integrated graphics. Optionally you can use discrete graphics. With means the GPU is separate from the MOBO. These are additional cards that plug into a PCI slot of some kind (or AGP for certain generations of MOBOs). Typically this option is for gamers, or people who do graphical heavy type computer work like 3D rendering and stuff like that. There is also a way to combine integrated graphics with discrete graphics for further performance. Exclusive to AMD products only it's called “Hybrid crossfire” and is useful when graphical performance is required in limited space. Both AMD and Intel GPUs can do a duel GPU setup. AMD's being called crossfireX and intel's being called SLI. The cards have to be compatible, the motherboard has to support the feature among other things. You get extra GPU performance when 2 GPUs are working together. I imagine it being similar to when CPU cores work together. GPUs themselves, seem to me, like little mini motherboards. They have their own processor, and their own RAM. (Integrated graphics borrow RAM from the MOBO) There are other specs to consider such as the interface generation (PCIe16x, PCIe2.0, etc.) shader cores, RAM speed, and so on. I'm still wrapping my head around all of this sort of stuff so I can't make any conclusions at this time.

Pictured below are some expansion cards.  Top is a Video Card (GPU) in the AGP interface.
Below that is a sound card, and below that is a wireless card.  To the right is a USB expansion card.

Below is some differences between 2 standard PCI interfaces (black and blue/green) and AGP (red)

Below are the IO ports on the 4 expansion cards.


HDD is a Hard Disk Drive. There are a few different form factors and interfaces. I have 1 HDD in a 5.25” size. It's old, slow, and only 19GB. I have about 10 PATA 3.5” HDDs, a few SATA 3.5” HDDs, 4 PATA 2.5” HDDs, and a 2.5” SATA SSD. HDDs are usually measured in size and speed. For Example: 80 GB size, 7200 RPM speed. 7200 RPM speed is typical. You get the best bang for your buck with that speed. Faster HDDs get expensive fast. Slower HDDs can bottlneck a system. The HDD is where your data is stored. The inside of an HDD are shiny disks where magnetic needles write the data onto them. (Don't have magnets near you computer, HDDs, or anything of the sort.) HDDs are usually pretty sturdy and can last a very long time. Sometimes they go out. I've had about 3 go out on me in my lifetime. It's always a good idea to have a separate HDD for backups. Sometimes an HDD that is going bad can be repaired with an old-fashioned-write-everything-to-zeroes type format. An SSD is a Solid State Drive. Where instead of magnetic disks it uses flash memory chips, much like a USB Jump Drive. They are faster, cooler, lighter, quieter, and more power efficient than HDDs. There is no disk to spin thus it's faster, produces less heat, weighs less, draws less power, and produces no noise. They are extremely expensive. I bought an SSD last year for 60 dollars and it is a 120GB. Just last week my friend bought a 1TB HDD for 55 bucks. That is more than 8 times the memory for less cost.

Below are 3 Hard Drives.  All PATA (IDE) interface.  Left to right is a 5.25" HDD, a 3.5" HDD, and a 2.5" (Laptop) HDD.  5.25 HDDs aren't very common.

The PATA and Molex and jumpers found on the rear of IDE drives.  The Jumpers are for setting the drive as a Master or a Slave.

Here is a 2.5" SSD.

It uses SATA connections making for a much slimmer interface.

Optical drives, also known as ROM drives are almost fading out. Streaming, downloading, and flash memory are the new thing. ROM means “Read Only Memory”. That Blue-Ray movie you bought the other day is ROM. Meaning you cannot pop that disk into your computer and change the data on it. Same goes for CDs, DVDs, HDDVDs, etc. There are some CDs and DVDs that are re-writable but it still requires an entire disk erase to do. Another thing that I think phases out ROM is the ability to write ISOs, or disk images. Your HDD is faster than your ROM drive. You can use your ROM drive to rip an image of the disk to your HDD, you can then mount that disk's image in a virtual drive that doesn't really exist and your PC will play it as if you had just popped in the disk. Only now it will play it faster. And you don't actually have to keep the disk on hand anymore. Having ISOs can eat up HDD memory space quickly though because they are essentially uncompressed. And if your HDD burns out, so does your data on it. So there are pros and cons to everything.

Top Drive is an old PATA CDRW.  It can only read, write, and re-write CDs.  Below it is a BlueRay ROM.  It can read BlueRay.  It can also read, write, and re-write DVDs.  And it can also read, write, and re-write CDs.  Notice how the old CDROM has a headphone jack, two buttons, and a volume knob.  These old drives could play music CDs without software directly to that audio jack.  A feature I used frequently in my high-school tech classes.  Running Music software in addition to the CAD program I was learning slowed the system down.  This feature solved that for me.
Below are the PATA and SATA interfaces of the same drives.

One last thing.  Earlier I mentioned a QVL.  That is a "qualified vendor list".  Every motherboard has one.  Just because a MOBO says it takes DDR3 RAM does not mean it will take just any DDR3 RAM.  When you build a system I recommend doing the following: Decide on the form factor, find the best MOBO in that form factor that fits your budget and specs, download the QVL and purchase your CPU and RAM based off of what that list says is supported by the MOBO then go from there.  Returning hardware takes time and costs money.
Well, in a nutshell those are my hardware basics. Some time in the future I'll do a software basics. I'm not a programmer, nor do I write code. But I can install an operating system and have a pretty good library of free PC software that I would call a must have for those who want to tinker with PCs.

Byebye.