OCulink and Thunderbolt

Oculink and Thunderbolt 

Thunderbolt is hardware interface that connects external peripheral to a computer.

It was developed by Intel and Apple collaboration and is proprietary product.

There are four versions and version 5 planned for the future with bus speed of 80 Gbit per second

1 and 2 supports 20 Gbit and 3 and 4 supports 40 Gbit per second.

1 and 2 have 20 pins 3 and 4 has 24 points.

 

They have fast and slow data transfer lanes but only selected lanes are connected to data access. Other pins are for grounding and power supply.

PCIe is Peripheral Connect Interphase Express for high speed connection of the motherboard (internal)  to  an external hardware.

 

OCulink port and cables are used to connect to the external devices to the computer motherboard, directly unlike the thunderbolts which are intermediate connections. 

This is to prevent latency in data transfer. 

This factor is very important in playing games in high fps rates and pixel resolution. 

 

Physiology of Motion

FPS means frames per second, Medical Terminology, the brain can see individual frames if the are moving slow. If my memory of undergraduate physiology is right anything above 36 frames per second, the brain interpret as a motion .

There is also lag of election transfer from eye to the brain and back to the eye to see the picture of image. This is about milli seconds that depends on the length of the never. An impulse from toe of the toe takes longer than from the tip of the finger.

This called latency and these films guys have taken this word from medical terminology, I believe.

This comes from reeled motion pictures. The reel has to run at least 36 per second to emulate motion but there is latency of the film projector, too. When we take all these factors into consideration 24 frames per minute has no strain for the eye (brain does not feel pain but the eye does)

Even though one need 36 frames for motion for practical purposes for videos 24 frames per minute is barely enough considering the latency factor. Even though, light travel in space without scatter there is an element of scatter and that is why we see the sky as blue not white.

There is something called spectrum of energy, too and the eye uses certain part of the spectrum for (analog vs physiology) for visualization and we can distinguish only about 16 to 24 colours, whereas the computer can distinguish million colour shades. I am guy with colour blindness which I realized playing billiards on dim light (not in natural light) at night which is getting worse with age.

By the way, we had worse medical teachers of that time, who were learning physiology and anatomy with us. They had gone abroad had got PhDs and they were meant to train them in methodology in a science and not teaching. Our teachers came from Carlo Fonseka Era but Osmund Jayaratne was my fovourite with his brilliant exposition of matters about clouds and lightening and many other topics in physics. 

I loved physics and hated medicine.

Let me come to digital facts.

Digital technology of current era exploits human physiological facts and human weaknesses and use high frame rates of video games to entice people including an old guy like me. 

It is an illusion of motion.

I will leave at that.

 

Graphic cards manage the pixels and rendering and that is why they have lot of pins (20 to 24 pins). 

Not all pins are used for data exchange and some are reserved for grounding and power supply.

They work on 12 volt direct current and the heating that generate while running is due to speed of data transfer and also due to components (transistors, capacitors and gates) within the CPU, RAM, GPU and the Hard Disks. 

These components are connected in parallel and they work independently. Therefore, the current that runs in parallel may vary from 3.3V, 5V and 12V.

The AC power supply which is 220 or 110 is stepped down to direct (battery current) current of 12V and for some components 3.3V and some 5V.

CPU cords have 8 pins.

GPU cords have 20 pins

ATX Motherboard power cord has 24 pins.

There are no components needing series current, except perhaps CMOS battery supply on a computer. 

The advantage of parallel current is the system does not breakdown due to one component failing. 

That is why computer is better gadget than a bulb or an iron or a fridge.

OCulink is the connection system to PCIe internals and externals.

Small firm factor

Direct Connection as opposed to intermediate like thunderbolt connection.

 

It uses PCIe connection

Peripheral Connect Interphase Express

 

Connect to external PCIe

Connected to Graphic Card

Connected to SSDs and docking stations.

Connects the motherboard to the external expansion cards like, Graphic cards, external SSDs and  Network cards.

 

1. Fast

2. Cost effective

3. Less interference  with other electrical circuits.

Prof. Osmund Jayaratne -A lifetime of teaching

Prof. Osmund Jayaratne retired from the Physics Department, University of Colombo and Peradeniya, after a long and distinguished career spanning 44 years. His primary research interest was terrestrial a cloud physics. In his teaching, Prof. Jayaratne mentored more than a thousand students. He also served Sri Lanka in the area of policy related to higher education.
In addition to teaching, Dr. Jayaratne also conducted research on the lightning patterns of Sri Lanka in collaboration with Prof. Lakshman Kannangara.

Loss of sight

A few years after retirement, Prof. Jayaratne’s eyes developed cataracts. Lens implants, a new procedure in Sri Lanka at that time, were attempted. An infection occurred in one eye and spread to the other. Despite repeated surgical interventions, Prof. Jayaratne suffered complete loss of sight in both eyes — confining him to his home in a nearby suburb of Colombo. His wife, Joyce, is his eyes to the world. She reads to him the latest scientific developments reported in newspapers and magazines.