RAM Latency vs Frequency - Why It's Important - ThioJoeTech

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[manofmars]

latency is like how fast someone gets off the couch

frequency is how many things the person can get done while off the couch for a certain amount of time.

[ReverenXero]

Thanks for putting these together, I am a long time IT professional and I try to educate my clients as to the "why" something works the way it does. I am a big fan of education and knowing how a tool works. I would like to add a tail on to this, as I think that this topic is important enough. Pro Tip: This may require a little math or at least the spreadsheet mentioned in the video. There is one more piece to the performance puzzle. That is how much data your CPU will crunch through per cycle, and how it matches up with the operations/second - Total Bandwidth. Try and avoid too much of a difference on either side. if you are starving your RAM, (RAM frequency higher than how much data the CPU sends back, in multiples that can leave a remainder product. This will cause the RAM to fall  into wait states or Idle, and in the case of video games, can cause a "stutter" (another thought on this at the end). If your CPU is too fast then, obviously, the RAM gets overwhelmed. When this happens the buffer tells the CPU to go into wait state and operations are paused until the RAM can catch up. Most public sector CPU's have a small finite amount of on-board cache (L1, L2) to hold these commands/information. High end CPU's can be as high as 12MB. Not a lot relative to RAM these days.
About game stutter: If you have ever installed a new graphics card and notice a game you are used to playing is now stuttering even with the HUGE COSMIC POWER of a new card. You have even lowered the graphics settings trying to even it out to no avail. What is really going on is the new card has evolved. There is probably newer logic that handles things like shader operations, or light vector/reflection calculations more efficiently. Freeing up clock cycles. So again, when you lowered the settings, you effectively are starving your data bus and GPU, and they are initializing that wait state until more data has been processed. Stutter. Try increasing the graphics/effects level in your game. In this situation, it will respond favorably. Your new card can take it. Just a 2 cents, I found relevant to this GREAT POST!!

[ThioJoe]

Watch this video before you buy any more RAM.

[InfoTeddy]

I'll remember this next time I download more ram!

[asim.r]

Coming from an assistant professor of engineering, very nicely explained man. I know many professors who can't explain shit.

[ThioJoeTech]

Ever wonder what the heck CAS Timings were? Well they're more important than you think.

[florinpandele]

You forgot to mention that the Mainboard has to support the frequency and latency of the memory you buy, and also you may have to manually setup the latency in bios for high performance ram, otherwise the ram will run at some defaulted "auto" latency.

[AlsoIUseArch]

Thanks for doing all the hard work for me :)

[MusicForKidsWorld]

i dont install more ram because i dont want to get a virus

[guanyu]

For most normal gaming and all normal work, RAM capacity is the most important, just pick the best cost with the capacity you need. Faster RAM has almost no influence to your PC performance (some consider that an extra 1-2 fps is already a huge impact, I won't argue with that).
Aiming for faster RAM will be beneficial mainly if you do content creation and on some games e.g. GTA V. Here, keeping cost in mind you would probably want to find the best RAM for you after you decided the capacity you will need. The calculation in the video will spin your head off in real life...try this instead...which is basically the same...Just remember, this will be less precise but a lot easier to remember.
Just do simple math: Freq/latency is A. Look for RAM kits with the highest value A with the best cost you can find. You will then find e.g. 1600/8= 200 is as fast as 2400/12=200. In this case, no need to spend more for the 2400MHz CL12, if the 1600MHz CL8 is cheaper. (not very realistic example, this is only for example)

[abandonedmuse]

Awesome thank you! I didn’t know latency was in RAM. I had heard of it in graphics cards but now I know more! You are awesome.

[Dan-orcu]

This is by far the best explanation of ram latency/frequency I've ever seen. the excel spreadsheet was the cherry on top.

[xfernandoz]

So well explained! I watched several articles about this and nobody explained this better than u. Congrats. And thanks for the tutorial.

[tomtexas]

Any one else notice the tube of vasaline?

[HiTechDiver]

Good Video. Being CompTIA 801 and 802 certified, I appreciate 1.) That someone covered this aspect of RAM, as I haven't seen another video specifically on latency, and 2.) That you did a very good job explaining it.

[mevilmom]

that was extremely informational! I now am questioning my RAM purchase.

[samitechcookie]

I just love how he looks in the camera. This is just awesome :D
All your vids are great, Thio! Thanks :)

[henriroggeman]

One thing. Faster memory with higher latency will perform better than the slower memory with matching lower latency once the request is received because you don't need to send a request for every byte of data in memory. ;-)

[karimballan]

I watched every popular video about the subject and I never understood RAM speeds/latency .. until i watched this video
Great video Thank you!

[MrCJHamill]

Thanks mate. You broke it down very clearly and have made it easy to understand.

The only other thing I would have added is there are usually sets of CAS numbers quoted instead of a single CAS number. I don't understand about these sets.