Hey if you are seeing this, let me tell you, this is the best video in KZfaq if you want to understand the concept of virtual memory, and others in simple and sweet. Perfect! ❤

Holy crap. KZfaq algorithm finally came through. This is some amazing content.

Fantastic video. I'm taking a OS course at university and we have a virtual memory assignment. The hand out documents left me feeling confused and a bit lost, but then this 20-minute video made all concepts clear as day. Thank you for putting effort into making these videoes, you earned a new subscriber!

Thank you for the video. The explanation was clear, structured and concise, better than most other explanations on youtube.

This is amazing! More detail than most Operating System courses in 20 minutes. Awestruck!

This might be the best content I have found on KZfaq this year. You explained these concepts in ways my teachers couldn’t, and you did it for free too ! You have my respect , and subscription haha !

I had a course back when i was in engineering school, the professor did a horrible job explaining memory and virtual memory, I ended up hating the class and i never really understood how it worked. until this day when I watched your video, you did an excellent job, I wish youtube had something like this before. Fast forward today, I work as a sysadmin/infra engineer and i really didn't have an idea how virtual memory works, again until I watched your video, thank you for the effort you put here, I am sure many will watch it and gain valuable informations.

There's a quite good reason 4 KB is used as a standard page size. In most disk partitioning software the minimum data you can read/write to is 4KB, so it can move it in one swoop

Thank you for this amazing video! It's truly refreshing to encounter such well-scripted and nicely illustrated content. It makes really enjoyable trying to learn such complex concepts.

Amazing explanation, always wanted to know core knowledge. Thanks, keep up with these videos!

Excellent description on how cpu/memory/os are working together! Well done!

The variety of content provided is much appreciated.

That's a very good, high quality production with a top notch explanation! Keep making more.

Wow! Clear, concise and very neat animations! Subscribing to a channel after a long time!

Wow, I was really surprised! I was just relaxing on KZfaq to fall asleep and came across your video. I thought it might be trash, but it turned out to be very good with excellent detail and explanation. Great job! Best video on youtube so fare 🎉🎉🎉

wow!! never felt like a computer science before. learned a lot on this clip. keep them coming

This is the BEST explanation i have had about this topic. I am a newbie to such concepts and you have explained in such an elegant way. Liked n subbed

I wanna thank the youtube algorithm for recommending this video. This is absolute gem for explaining the Virtual Memory concept.

This video is really good, the way that you simplified Virtual Memory is amazing!

the graphics really helped me visualize how this works! youre a lifesaver ^^

Dude, you're videos are so helpful, thanks so much!!!

An excellent, succint and illustrative explanation :)

the second part is a bit more complex but I love the visuals + explanation nonetheless. thanks for the effort put into making this one!

please never stop, really good video

This is awesome, made things so clear to me. Thank you.

Ahh…the swap file in Linux!!! I used to allocate a portion of my hard drive for swapping!! Wow!!! Such a refresher !!

What an excellent overview. Nice job. It clarified a few things i was unclear about.

absolute banger of a tech channel thanks, will watch again -IGN

Wooow this video is awesome! Great work on the animations and examples 🤝😎

Svaka cast burazeru. Ovo sam na faksu radio, ali si dosta bolje objasnio.

Thank you for your high quality work. 👏👏👏

Very clear! It helps a lot, thank you very much!😀

Wonderful illustration of Virtual Memory. Good Job !

Thanks, crazy good vid 👏

Oh Juniors, 1GB is huuuuge for old-school guys

Thanks! You explained this better than any professor did when I was still in university. Much appreciated, will be sending this video to people who ask me about this 😅

Great video ! I am preparing for my master degree and found this gold in KZfaq. I believe I can ace my upcoming OS class. I have liked your video and subscribed to your channel. Thanks a lot for the video. Greatly appreciate it.

Thank god I found this gem before my exam!

Can't thank enough for this

I have to words! That video is amazing! You won yourself a new subscriber, my friend! ❤

Your explanations are amazing Thank you, I hope to see more

Im just sitting here fascinated...and it makes sense.. knowing just the basics... nice work...a dumb thing to say but this is relaxing...straight to the point ..ask a question ...then answer it... terrific

Amazing video, wish I saw it while still in college 😊

that music player & video game example is hilarious to think about

watched the first video in this channel, subbed!

thank you, this video was very clarifying.

Finally ... a proper explanation! I say this because countless self-made experts get it wrong. You see, Microsoft seems to have invented the misuse of the term "virtual memory" around the time of Windows 95. They used the term VM to describe what is really demand paging. Microsoft publications at the time did NOT make this mistake. (See Jeff Richter's excellent book describing the internals of Windows NT, published at the time.) But in the settings UI ... I guess "virtual memory" sounded more appealing to Microsoft than "demand paging". So they misused the term ... and misled generations of self-made CS people who subsequently grew up unaware of the misuse. They often claim that VM size can be adjusted. (It cannot be.) They believe that the disk swap/paging space is virtual memory. (It is not.) You see, virtual memory was created as a MAPPING PROCEDURE that solved the long-standing problem of mapping a program binary into the run-time address space of a computer. It was preceded by address space paging (remember the early 80x86 paging registers?). This was present in minicomputers as far back as the late 1960s. Paged memory was, in turn, preceded by run-time relocation ... a tedious run-time editing of a binary to "patch" all of the code addresses and data addresses within a program binary before execution could begin. VM is superior to both of those methods. Meanwhile some systems implemented something called swapping ... a predecessor of demand paging. When swapping, a program's ENTIRE memory consumption is swapped to disk to make way for another program. This mechanism allows the system to get around memory size limitations ... but it performs a lot of disk swapping! Demand paging goes one better by swapping only small blocks of memory. And even better, it loads only portions of a program when needed. No need to load an entire program when most of that program code won't be executed any time soon. It's all quite efficient. Virtual memory is not demand paging, and demand paging is not virtual memory. And you don't have to use VM with demand paging. And you don't have to use demand paging with VM. But the two appeared at a similar time in computing history ... and they work hand in hand to improve performance. So you always see both of them together. This video correctly presents a unified view of demand paged/virtual memory. Nice work!

bro you are amazing, love your energy

clear as water, thanks!

Wow, good video. Good job and thanks for sharing.

This is a very good, concise and clear explanation, please keep the work's up, I really enjoyed it : ) PS: can you make a video about how compression algorithms work?

From Aritmetic concepts , the virtual memóry obeys bijective function (injective and surjective ) about Domain and Image . It is unbelievable !

Good explanation and yes 4kb is the optimal size to move , its similar like why the size of a page node of a BTree in a database is of 1024 because its optimal for I/O. But I also would like to see the explanation of exactly what does MMU do here.

Thank you for providing such valuable content. The examples you shared have greatly enhanced my understanding of the working principles of virtual memory.

such a good video, you are the man !

شكرا thanks 👍 it was helpful

Liked, subbed, turned on all notifications.

Starting off with the “bad old days” only being 4GB definitely lets me know I’m old! Just like running out of 32bit address space “must” have been back in the 1950s or something 😂

Superb...! Love it..❤

Can u make a video for registers, What are they used for… in a way that we can understand the assembly language

8:06 Correction: A word is two bytes in size, not 4. A double word (DWORD) is 4 bytes. And cpu's don't work with words necessarily, but general purpose registers of x32 bit cpu's are 32 bits in size. And 64 bits for x64 gprs.

Bravo !

Greate Video. Thanks

Very well explained

I've written some 6502 assembler for the BBC Master, where the most complicated it got was having to write to a memory-mapped hardware register to switch banks of RAM so that you can access 128Kb with a 16bit address bus. It's a bit mind-boggling to think about all this indirection that goes on in modern memory systems. All this back and forth would bring 8bit systems to their knees!

Truly amazing

Thank a lot.

Very helpful ❤❤

nice video bro!

Can you next teach us about deditated WAM?

it was so good

thank you man

This was great. I'm a bit lost (11:09 in) how virtual has 12 to 31 bits left and we somehow fit this in physical address that is 12 to 29. So we are missing 2 bits. What is happening with the last two bits. What did we do with it or are they ignored and we hit a limit of virtual because the size of the physical

I'm already at about 10 minutes and have about 80% understanding. What do you recommend I look for? Or if you have some resource/s I would be grateful

@0:54 and before that there were 16 bit CPUs that could only address which was only 64 Kilobytes. In the early days it was more around the problem with memory collisions rather then accessing something that is out of range. In the 1960s you wouldn't find the kind of problem you're talking about because the processing power was too expensive to have that kind of problem. Paper Tape and Punch Cards don't have the same problems with accessing memory out of range.

Well explained

great video. i didnt get 2^32 adreess for each byte = 2 ^ 30 words

Great video. So you mention that physical address is the "memory RAM". You also mention the "page tables" are store in the "memory RAM" and how there are difference level of page tables and some can be store in disk. Is virtual memory also store in the "memory RAM"?. I know I have to rewatch this video and keep studying to fully understand and that I have gaps in my knowledge. So in a high level the OS has to do a mapping between virtual memory and page tables. And then between page tables and physical address? Thanks.

Hey man, can you make same video with gpu and cpu? Your explanation is so good

Perfect. you did great job here, this topic became very easy after that sweet explanation but I need u to correct my info if I am wrong! in old days we know that byte is 8 bits word is 2 bytes = 16 bits dword is double words = 4 bytes = 32 bits so, is it changed those days as you claim in this video here 8:08 !!! is word become 32-bits ? thank you

Can you also call a programm a process with threads etc. or are those two seperat things?

0:35 As far as I understand, 4Gb of memory means less than 4Gb of RAM. CPU thinks that ROM and south bridge devices are memory as well.

you are a legend

Is Page Table update and TLB update treated as 1 atomic operation? If yes, how do we maintain atomicity? If no, how do we handle scenarios where the TLB has stale entry?

Me traga mais sugestões assim de canal algoritmo do KZfaq, very good

KZfaq suggesting me at 2 am here. thank god it did. I can sleep well now.

Very good

Actually GiB refers to Gibibyte which is a power of 2. And Gigabyte is a power of 10 :)

Quite good video. Just a minor comment. You use the word 'Security' in sections but I would call it 'Liability'. Thanks,.

is there a chance that a virtual page does not map to eithjer the disk or the physical page? what happens in that case? 12:45

❤

subbed.

11:38 I’m wondering when you copy the last 12bits to the physical memory, why the number changes from 0110 0111 1000 to 010110011110

Kindly make part 2 for DP

Your channel is a masterpiece! The Discord link is invalid or expired. Would you please comment it here? Thank you

I guess this is the system that downloading ram uses, bc I always wondered how you could get more ram from a website.

does page table also handle swap, putting memory onto hard disk?

10:39 All pages are 4096 long except Pages 2, is that a correct?

How to make (edit ) this type of content? Can anybody share software name or any youtube playlist to learn

U r a young man. I remember only 640k